Method and testing device for thermomechanical testing of sample

Abstract

The invention relates to a method for thermomechanical testing of a sample (50) to which a high-speed thermal mass flow (22) is applied. The invention also relates to a testing device (10) for thermomechanical testing of a sample (50), comprising a chassis (30) having a receptacle (32) and an application member (20) for providing a high-speed mass flow (22).

Description

Technical Field

[0001] The invention is directed to a method for thermomechanical testing of a test specimen. The invention is also directed to a testing device for thermomechanical testing of a test specimen. Background Art

[0002] Fire shielding must have a sufficiently high resistance to burn-through, in particular a resistance to burn-through in terms of time (zeitliche Durchbrennbeständigkeit), and must shield the heat of the fire. An example is the case where the battery of an electric motor-driven motor vehicle is shielded relative to the passenger compartment of the vehicle. It should be designed to ensure that the flame in the battery does not penetrate directly into the passenger compartment, but allows the passengers to safely stop and leave the vehicle or be rescued within the period specified in the test rules. Other applications of such shielding include fire shielding devices in buildings, ships or aircraft. Therefore, it is necessary to select or develop materials with appropriate properties and a sufficiently high resistance to burn-through in terms of time for such shielding. To this end, it is necessary to test the expected material ("action characteristics (Einwirkungscharakteristik)") according to the energy flow and material flow of the action. In the context of the present invention, this test is referred to as a "thermomechanical test".

[0003] It is known from the prior art to test the intended material in a realistic device using practical means. The degree of damage to the fire protection shield is determined by observation of the test specimens. The disadvantage of this solution known from the prior art is that it allows only a very imprecise determination of the fire resistance and its dependence on the action characteristics. This is due to the fact that there are variabilities in the energy and material flows. In addition, the reproducibility is very insufficient, so that an objective test process for testing the test specimens is not possible with such a device. Summary of the invention

[0004] Therefore, it is an object of the present invention to provide a method for thermomechanical testing of test specimens which ensures improved reproducibility. Furthermore, another object is to provide a testing device for thermomechanical testing of test specimens which provides reproducibility and has a compact structure.

[0005] This object is achieved by a method having the features of claim 1 and a testing device having the features of claim 22 .

[0006] The dependent claims are respectively related to preferred embodiments or improved examples of the present invention, and their respective features can be freely combined with each other within a technically reasonable range and, if necessary, can also exceed the category limitations of the various claims.

[0007] The method according to the invention is a method for thermomechanical testing of a test specimen, wherein a high-speed thermal mass flow is applied to the test specimen.

[0008] Thanks to the method according to the invention, accurate fire testing of test specimens can be achieved without the outlay of actual equipment. As a result, test specimens can be tested faster and more economically before their material is used for fire protection shielding, or a suitable preselection can be made from a large number of materials before further testing. The damage mode of the test specimens, in particular the damage mode on the side facing the mass flow, can be evaluated in terms of relative damage intensity, and different test specimens can be objectively compared with each other. Another advantage of the method according to the invention is the increased repeatability compared to the prior art, so that when the method is performed again with similar test specimens, technically identical results are obtained, thereby creating an objective test method that provides the possibility of comparing different test specimens in an objective and standardized manner.

[0009] After carrying out the method according to the invention, the specimen is damaged, although it does not necessarily have to be burned through, ie it is intact. However, the specimen may also be burned through.

[0010] In an advantageous development of the method, at least one measured value can be determined by the determination device. The measured value is not limited to the determination of physical quantities (e.g. force or temperature, acoustic measurement variables); for example, this can also refer to the determination of an image. The term "measured value" should therefore be interpreted broadly. Preferably, the measured value is determined before and / or during and / or after the application of the high-speed thermal mass flow. By means of the determination device, the information value of the method according to the invention can be further increased.

[0011] In an advantageous development of the method, the time period between the start of the application and the occurrence of burn-through of the test specimen can be determined by the determination device.

[0012] By means of this refinement, the time period until the test specimen burns through can be accurately determined, which time period can be regarded as a measure of the fire barrier performance.

[0013] In an advantageous development, the force acting on the specimen as a result of the application is continuously determined by the determination device. The determined force or force curve can provide information about the acting mass flow, so that this information can be used for normalization between two or more runs of the method according to the invention and thus increase the reproducibility. In other words, fluctuations in the action characteristic can be determined and these fluctuations can be taken into account accordingly in the evaluation.

[0014] Preferably, the time period between the start of application and the occurrence of a force drop based on burn-through of the specimen may be determined.

[0015] A particularly preferred method is a method for determining the time-dependent burnthrough resistance of a test specimen, wherein a high-speed thermal mass flow is applied to the test specimen and the force acting on the test specimen due to the application is continuously determined, wherein the time period between the start of the application and the occurrence of a force drop due to burnthrough of the test specimen is determined.

[0016] The force is determined by a determination device. To this end, the force introduced into the specimen by the high-speed thermal mass flow is continuously determined throughout the application time so that the time period between the start of application and the occurrence of a force drop based on or due to a burn-through of the specimen can be determined. The time is determined using a time measuring device so that the time period, i.e. the time difference, between the start time point of application and the occurrence time point of a force drop based on a burn-through of the specimen can be determined. The determination device may include a time measuring device.

[0017] In other words, during the entire time during which a high-speed hot mass flow (hereinafter also referred to as mass flow) is applied to the sample, the force introduced into the sample by the mass flow is determined by a determination device designed as a force measuring device and can preferably be plotted in a force-time curve (also referred to as force-time profile). As soon as the sample burns through, the force drops, i.e. the force introduced into the sample by the mass flow suddenly decreases, since the mass flow no longer introduces any force into the sample, or at least only introduces a small amount of force, since the mass flow flows through or passes through the sample due to the burn-through of the sample. The point in time of the force drop corresponds to the point in time when the sample burns through, so that the time period between the start of the application and the occurrence of the burn-through of the sample can be determined very accurately. The point in time when the force drop starts preferably corresponds to the point in time when the burn-through of the sample starts. By means of the method according to the invention, this time period can be determined with an accuracy of up to 1 / 10 (0.1) second.

[0018] The time-dependent burn-through resistance of a specimen corresponds to the time period between the start of application and the start of burn-through of the specimen (i.e. the breaking through of the high-speed hot mass flow flowing through or through the specimen). The time-dependent burn-through resistance can therefore be regarded as a component or material property, which can give information on the fire protection properties and resistance to thermal effects of the component or material. Preferably, the method according to the invention is suitable for determining the pulse course (pulse curve), in particular by continuously determining the force.

[0019] A high-speed thermal mass flow (or mass flow for short) is provided by an application member and introduces heat and force into the sample. The high-speed thermal mass flow can be in the form of a jet directed at the sample. The force introduced into the sample by the mass flow (i.e., the force acting on the sample) is provided by the impact of a mass flow having a flow velocity. Particles can be added to the mass flow, wherein the mass flow is particularly preferably a gaseous flow. The maximum value of the flow velocity of the mass flow is preferably higher than 50m / s, particularly preferably higher than 100m / s, and very particularly preferably higher than 200m / s. Preferably, the flow velocity is supersonic and higher than 300m / s. This flow velocity is closest to the thermal runaway condition of the accumulator. The temperature of the mass flow is significantly higher than the ambient temperature, so that heat is at least partially transferred to the sample and its temperature is increased. Preferably, the maximum temperature of the mass flow is preferably higher than the melting temperature of the sample. The maximum temperature of the mass flow is preferably higher than 500°C, particularly preferably higher than 600°C, and very particularly preferably higher than 800°C. Thus, for samples made of materials with relatively high melting points, the burn-through resistance of the relevant time can also be determined. Preferably, the maximum temperature that can be generated for the sample is higher than the melting temperature of the sample, in particular, the maximum temperature that can be generated is higher than the temperature of the mass flow. The temperature of the mass flow is higher than the ambient temperature, so when the mass flow hits the sample, the kinetic energy of the mass flow is converted into thermal energy, i.e. the temperature of the sample increases. As a result, the sample can be heated to a temperature higher than the mass flow itself. This can save energy and costs.

[0020] Burning through of a sample can also be referred to as breaking through of the sample, which means that the sample breaks through the obstacle that the sample constitutes for the mass flow. Burning through of a sample means that the material of the sample is at least partially melted and / or burned by the mass flow, so that the geometry of the sample is changed as a result. In other words, the material is at least partially melted and flows out of the area of ​​influence of the mass flow and / or is at least partially burned.

[0021] In a preferred refinement, the introduced force is determined continuously with a time resolution of at least 1 / 25 second. Thus, 25 force measurements are recorded per second. In a particularly advantageous refinement, the time resolution is at least 1 / 50 second. With this time resolution, the accuracy of the method according to the invention can be further improved.

[0022] The test specimen can preferably be designed as a test piece, for example in the form of a plate, or as a component having a geometry different from that of a plate. The method according to the invention thus offers the possibility of testing both a plate-shaped test specimen and a real component such as a housing or a cover simultaneously for their time-dependent burn-through resistance.

[0023] Preferably, the force drop that occurs due to the burning through of the specimen can be greater than 50%, particularly preferably greater than 80%, of the force introduced before the force drop. Particularly preferably, the force drop can be greater than 50%, very particularly preferably greater than 80%, of the force introduced immediately before the force drop. As a result, the force drops sharply during the burning through compared to the previously approximately constant force, so that the time and time period of the burning through of the specimen can be determined precisely. The force drop preferably occurs in less than 2 seconds, particularly preferably in less than 1.5 seconds and most preferably in less than 1 second. The force drop thus represents a jump in the force-time diagram, so that the time of the beginning of the force drop and thus the beginning of the burning through can be determined precisely.

[0024] In an advantageous development of the method, the mass flow flows through the opening in the sample produced by the burn-through. The mass flow therefore does not flow towards the edge portion of the sample, but preferably towards the central portion of the sample, so that an opening preferably having a substantially rounded shape, in particular a substantially circular shape, is formed in the sample due to the burn-through; after the burn-through has occurred, the mass flow flows through the sample. Since the mass flow flows through the opening and therefore at least no longer completely strikes the sample, after the burn-through it no longer introduces any forces into the sample or only very small forces compared to the point in time before the burn-through. In other words, the mass flow succeeds in achieving the burn-through of the sample and the resulting opening, so that it can flow through the opening unhindered, i.e., without significant forces being introduced into the sample. As a result, the force drop caused by the burn-through can be more abrupt and the measurement accuracy can be further increased.

[0025] In an advantageous development of the method, the point in time at which the application begins is determined by the force increase. At the point in time at which the mass flow is applied to the specimen, a force is also introduced, so that the specimen, which was previously not loaded, is now loaded with the mass flow, i.e. a force is introduced into it. From this, the point in time at which the application of the force increase begins can be determined. It is also conceivable and possible that the point in time at which the application begins is different from the point in time at which the force increase begins, but is a later point in time (e.g. a point in time with a predetermined time interval from the point in time at which the force increase begins), or that the point in time at which the application begins is the point in time at which the force reaches a first maximum (first turning point in the force-time curve), e.g. caused by a starting pulse of the mass flow. In this way, for example, a preheating phase of the specimen can be taken into account and the determination of the time-dependent burn-through resistance can be further improved.

[0026] However, in an alternative embodiment of the method, it is also conceivable and possible to determine the point in time of the start of application, for example the ignition point in time, by the start of the high-speed hot mass flow. By means of such an embodiment of the method, for example, the ignition of a fire occurring on site can be simulated, since the point in time of the start of the mass flow can be regarded as the start of the ignition of the fire. The method according to the invention thus provides not only a possibility for determining the time-dependent burn-through resistance. Instead, the method according to the invention also provides the possibility of determining the ignition point in time, the point in time of the start of the force increase and the point in time of the first maximum value as well as the final time period in a single run, thereby providing comprehensive results for the time-dependent burn-through resistance of the test specimen. The method according to the invention thus not only provides very precise measurement results, but also saves costs and resources.

[0027] In another advantageous improvement of the method, the temperature of the sample is determined. The temperature is determined using a temperature measuring device while applying a mass flow to the sample. The determining device preferably includes a temperature measuring device. The temperature measuring device can be designed, for example, as a thermocouple, a thermometer or an infrared thermometer. The temperature measuring device can preferably be designed as an analog or digital measuring device. Preferably, the temperature is determined continuously over time so as to record a temperature-time curve, which can be used to determine the burn-through resistance over time. The force-time curve can be recorded redundantly and in an analog manner. Preferably, the temperature is measured in the portion of the sample to which the mass flow flows. Particularly preferably, the temperature is determined on the side of the sample facing away from the mass flow. Thus, the temperature of the portion of the sample to which the mass flow is applied but not directly impacted by the mass flow can be determined. In other words, the sample shields the temperature measuring device. The side of the sample facing away from the mass flow is the side of the sample facing away from the side that is impacted by the mass flow before the burn-through. In other words, the back side is the back side of the side that is impacted by the mass flow before the burn-through. In practical applications, the side of the sample facing away from the mass flow is the fireproof side of the sample. Furthermore, this allows conclusions to be drawn about the thermal conductivity of the specimen.

[0028] In another advantageous development of the method, the temperature can be determined at a plurality of points on the sample. Thus, the temperature distribution and the temperature propagation, ie their change over time, can be determined.

[0029] In a further advantageous development of the method, the start of application can be determined by the exceeding of a predetermined temperature of the specimen, i.e. the point in time at which the application starts corresponds to the point in time at which the predetermined temperature (i.e. the predefined temperature) of the specimen is exceeded. As a result, the preheating phase of the specimen can be neglected when determining the time-dependent burn-through resistance, i.e. the preheating phase can be excluded from the time period used as a measure for the time-dependent burn-through resistance.

[0030] In another advantageous development of the method, the force and the temperature can be determined in a common data acquisition device. This can be done, for example, using a measurement calculator in the form of a computer. This provides the possibility of automatically evaluating the measurement results, for example by using the different determination methods explained above for determining the time period as a measure of the time-dependent burn-through resistance. The common data acquisition device can preferably comprise a multimeter. The determination device preferably comprises a data acquisition device.

[0031] Furthermore, in an advantageous refinement of the method, the impulse acting on the sample can be determined by the force acting during the time period. In this way, the force continuously determined during the application time can be used to determine the impulse or impulse curve introduced into the sample by the mass flow. The impulse essentially corresponds to the so-called impulse integral (Schubintegral) of the mass flow. The impulse integral can be used as a measure of damage. Preferably, the impulse can be between 1 Newton second (Ns) and 250Ns. It has been shown that it is particularly advantageous to introduce a mass flow of up to 1000Ns pulses into the sample. This saves costs and resources.

[0032] In an advantageous refinement, a thermal image and / or a thermogram of the sample can be recorded. This can be done, for example, using an infrared camera, whereby the determination device can include an infrared camera. As a result, the temperature distribution of the sample can be determined during the application time, which also makes it possible to determine so-called hot spots in the sample. The thermal imaging and / or thermogram is preferably performed on the side of the sample facing away from the mass flow. This has the advantage that the interferences caused by the mass flow are reduced and the shielded side of the sample is observed. In an advantageous refinement, the thermogram can be performed as a differential thermogram, thereby reducing the albedo. Thus, the burn-through resistance over time can be determined by a determination device comprising an infrared camera.

[0033] In a further advantageous development, the applied image recording can preferably be obtained with an image frequency of more than 30 images per second (frames per second; fps for short), particularly preferably more than 100 images per second and very particularly preferably more than 200 frames per second. The image recording can be performed, for example, using a high-speed camera, wherein the determination device can include a high-speed camera. The image recording preferably records the impact of the mass flow on the specimen and / or the side of the specimen facing away from the mass flow. Thus, the time-dependent burn-through resistance can be determined by the determination device including a high-speed camera.

[0034] In an advantageous development, the data acquisition device, which is designed as a computer, for example, can also record thermal images and / or thermographic images and / or video recordings of a camera in addition to the forces and temperatures.

[0035] Preferably, the data acquisition device is designed such that it automatically synchronizes the curves of the measured values ​​(e.g. force or temperature) of the individual measuring devices with the video recording and / or the thermal imaging and / or the thermograph using markers. Preferably, the obtained results are stored by the data acquisition device in a common file. For example, ignition pulses, optical or acoustic ignition signals, etc. can be used as synchronization markers.

[0036] In an advantageous development, the data acquisition device can be designed to evaluate the image of the spark on the side of the specimen facing away from the mass flow by automatic image evaluation in order to determine the time point at which the spark begins to fly. The beginning of the spark on the side of the specimen facing away from the mass flow corresponds to the burning through of the specimen. This can be done in addition to the force measurement or temperature measurement, but it can also be omitted.

[0037] In a further advantageous development, the data acquisition device can be designed such that the image is scanned by automatic image evaluation to determine the time point at which the application of the mass flow to the test specimen was started. In other words, the relevant time points for determining the time period (i.e. the time point at which the application was started and the time point at which the burn-through occurred) can be determined by automatic image evaluation of the image recording and thus the burn-through resistance can be determined. In this way, redundancy for other measuring devices can be achieved and the accuracy can be further increased. Alternatively, the automatic image evaluation can also be carried out without the use of additional measuring devices.

[0038] In an advantageous development of the method, an acoustic signal can be determined during the application. The acoustic signal can be determined using an acoustic measuring device, which can comprise, for example, a microphone. Preferably, the determining device comprises an acoustic measuring device.

[0039] The acoustic measuring device is preferably connected to a data acquisition device. Thus, all the acquired measurement data can be processed and synchronized in a common data acquisition device.

[0040] In an advantageous development, the acoustic signal can also be started before the application. This allows the point in time at which the mass flow to the sample is started to be determined acoustically, so that redundancy can be created here and this can be used as a synchronization marker for a separate measurement sequence. Alternatively, the acoustic evaluation can also be performed without the use of an additional measuring device.

[0041] Furthermore, the acoustic signal can also be used to determine the point in time at which the test specimen burns through. Thus, the time period can be determined by the acoustic measuring device as a measure of the time-dependent burn-through resistance.

[0042] Furthermore, the acoustic measuring device can also provide redundancy for other measuring devices based on different measuring principles. Furthermore, the determination of the acoustic signal offers the advantage that its measuring properties are not impaired by the generation of smoke during application, as can happen, for example, when using optical measuring devices such as cameras. This ensures that the burn-through resistance can be determined even if other measuring devices are impaired and that, due to the determination of the acoustic signal, no expensive retests are necessary.

[0043] In another advantageous embodiment of the method, the jet velocity of the mass flow can be determined. The jet velocity can be determined using a jet velocity measuring device, which can be done, for example, using Doppler spectroscopy. Preferably, the jet velocity can be determined spatially before the mass flow is applied to the sample. In other words, the jet velocity measuring device is arranged spatially between the application member and the sample. This has the advantage that, for example, in addition to the force or temperature introduced into the sample, the jet velocity can also be determined continuously and a diagram can be drawn over time so that any changes in the force curve / temperature curve can be compared with changes in the jet velocity curve, thereby further improving the measurement accuracy of the method of the present invention. The mass flow can be calculated by force and velocity measurement. Alternatively or additionally, the jet velocity can be determined on the side of the sample facing away from the mass flow, that is, here only the jet velocity of the mass flow is determined after burn-through. The jet velocity (Strahlgeschwindigkeit) of the mass flow can also be referred to as the flow velocity of the mass flow.

[0044] In an advantageous refinement, the test specimen comprises a material for a battery housing, or is a battery housing or a portion of a battery housing. The method according to the invention is particularly suitable for determining the material (i.e. the material for the battery housing or a portion of the battery housing) or the battery housing itself. The battery housing serves to accommodate and shield the battery. A battery is also understood to be a storage battery, in particular a lithium-ion storage battery for an electrically driven vehicle. In the event of a fire in such a battery, it is necessary to protect the occupants of the motor vehicle from the fire so that they can leave the vehicle unharmed before the fire spreads to the passenger compartment.

[0045] In an advantageous refinement, the mass flow flows orthogonally or at an angle to the sample. This increases the variability of the method, making it possible to apply the mass flow to the sample at an angle corresponding to the actual conditions of later use. Alternatively or additionally, it is also conceivable to adjust the distance between the application member for providing the mass flow and the sample in order to adjust the temperature distribution and the jet characteristics.

[0046] In a preferred embodiment of the method, the mass flow is provided by a rocket propellant charge, an acetylene burner with mass feed, flame spraying, a galvanic element or plasma spraying. These means are also referred to as application means. In particular, rocket propellant charges designed as solid composite propellant charges have proven to be particularly advantageous, since they provide a reproducible and partly constant (more uniform) mass flow over the application time, since the tolerances between the individual propellant charges are very low.

[0047] In an advantageous development, the galvanic cell is designed as a secondary battery, also referred to as an accumulator. The galvanic cell comprises at least one battery cell. The galvanic cell is particularly preferably designed as a lithium-ion battery. Due to this design of the application component, the specimen can be tested under quasi-real conditions.

[0048] In an advantageous development, the galvanic cell is preferably arranged such that the mass flow flows out of the galvanic cell against gravity. This offers the advantage that, compared to a suspended arrangement, no or only a small amount of flammable liquid electrolyte escapes from the galvanic cell before the mass flow flows out, thereby preventing uncontrolled combustion or even deflagration.

[0049] In another advantageous refinement, the fuel of the application member for providing the mass flow can be weighed at least before the start of application and after application; preferably, the weighing is performed continuously during application. Thus, the mass of the fuel is determined before or after or during application, so that a comparison can be made with the fuel consumption of other experiments, so that any faulty application member can be determined. The weighing can be done using a mass measuring device, for example in the form of a scale.

[0050] In an advantageous refinement, a mass flow can flow through the nozzle and thereby adjust the discharge characteristics of the mass flow. In this case, the mass flow flows through the nozzle starting from the application member and, after passing the nozzle, hits the sample, wherein the nozzle is preferably spaced apart from the sample. The nozzle has a predetermined nozzle geometry, which is designed so that the discharge characteristics of the mass flow provided by the application member can be changed and adjusted accordingly and thus adapted to the real conditions of thermal runaway, in particular with regard to temperature, injection opening angle and momentum. Due to the use of the nozzle, the mass flow can be changed so that the discharge characteristics are more in line with the actual situation, such as failures of lithium-ion batteries. In particular, the following geometrical features of the nozzle can be varied: the central nozzle hole, the opening angle of the cone, the length of the central nozzle hole and the length of the cone.

[0051] The nozzle is preferably used in conjunction with a rocket propellant charge.

[0052] Furthermore, a testing device for thermomechanical testing of a test specimen is proposed, comprising a base frame with a receptacle and an application member for providing a high-speed thermal mass flow, which can be directed to the test specimen.

[0053] By means of the testing device according to the invention, the fire protection properties of materials can be tested or preselected without great effort and expense.

[0054] The test device is preferably suitable for carrying out the previously described method with all the aforementioned refinements. Therefore, all the aforementioned features of the method and its advantageous refinements can be transferred to the test device accordingly. Likewise, all the features of the test device and its refinements explained below can be transferred to the method and its advantageous refinements.

[0055] Preferably, the test device has a determination device. Due to the determination device, the measured value can be determined before and / or during and / or after the application. Preferably, the determination device comprises at least one of the following devices: a force measuring device, a time measuring device, a temperature measuring device, an acoustic measuring device, an infrared camera, a high-speed measuring device, a data acquisition device. The determination device can have these devices alone or in combination.

[0056] Furthermore, due to the repeatable conditions (and their measurement), even if a specimen does not burn through, the relative burn through resistance of the specimens can be compared based on surface damage and / or backside temperature, allowing for effective pre-screening (variants of the specimen can be pre-selected) in order to subject the “best” specimens to further, more complex fire tests.

[0057] Preferably, the determination device is designed to determine the burn-through resistance of the test specimen, in particular the time-dependent burn-through resistance of the test specimen.

[0058] In this way, the time period until the specimen burns through can be determined precisely.

[0059] In an advantageous refinement, the determination device can comprise a force measuring device which is operatively coupled to the base frame and is arranged to determine the force introduced into the specimen by the mass flow.

[0060] The test device can thus be used to continuously determine the force introduced into the test specimen by the high-speed thermal mass flow over the entire application time. Thereby, fluctuations in the mass flow can be easily determined so that they can be taken into account accordingly when evaluating the test. Thereby, the test accuracy can be further improved.

[0061] Furthermore, the time period between the start of application and the occurrence of a force drop based on or due to a burn-through of the specimen can be determined. To this end, the force measuring device is preferably designed such that it detects the force continuously during the application time.

[0062] The chassis of the test device has a receptacle in which the sample can be received directly or indirectly (i.e., via an intermediate element). Preferably, the receptacle is designed as a recess or opening in which the sample or the intermediate element can be received, so that the sample is preferably held fixedly in a precise position relative to the receptacle at least in the direction of action of the mass flow.

[0063] The base frame can be effectively coupled to a force measuring device, wherein the force measuring device is arranged to determine the force introduced into the sample by the mass flow. In other words, the base frame and its receptacle are at least effectively connected to the force measuring device, thereby ensuring a force flow between the sample that can be accommodated in the receptacle and the force measuring device. As a result, the force introduced into the sample by the mass flow can be determined by the force measuring device.

[0064] The application member is designed to provide a high velocity thermal mass flow, the application member being oriented so that the mass flow will impact a specimen that can be contained in a receptacle. In other words, the application member is aligned with a position predetermined by the receptacle for the specimen.

[0065] In an advantageous refinement, the chassis comprises a temperature-resistant and fire-resistant material, such as a material made of steel and / or ceramic material. In this way, it can be ensured that the chassis is not damaged by the mass flow when a mass flow is applied to the sample, thereby increasing the service life of the test device.

[0066] In an advantageous refinement, the force measuring device can include a force transducer. A force transducer is also referred to as a force sensor or a weighing device. In particular, the force transducer can be designed as a piezoelectric transducer. Preferably, the force measuring device is arranged between the chassis and a rigid support structure (e.g. a machine tool, a base or a frame). In a preferred refinement, the force measuring device has a nominal force between 250 N and 750 N, particularly preferably 500 N.

[0067] In a preferred refinement, the force measuring device can be calibrated only for compressive or tensile forces, since the mass flow introduces forces with a previously known direction into the specimen and thus compressive or tensile forces act. This increases the accuracy and simplifies the calibration process. Standard weights of 1 kg or 5 kg are particularly suitable for calibration.

[0068] In an alternative embodiment, the force measuring device can be used to measure the displacement (stroke) of the chassis relative to the rigid mount, wherein the elastic element is arranged between the chassis and the mount. The elastic element may include at least one spring element, for example in the form of a spiral spring or a disc spring. Since the stiffness of the elastic element is known, the force acting on the chassis can be calculated based on the displacement of the chassis relative to the rigid mount. In an advantageous improvement, it is conceivable and possible to use a lever device to convert the displacement of the chassis so that the measurement accuracy can be further improved. In addition, an additional damping element can be arranged between the chassis and the rigid mount. In this way, vibrations in the system can be suppressed and the measurement of force can be further improved.

[0069] In an advantageous improvement, the determination device may have a temperature measuring device for determining the temperature of the sample. The temperature measuring device preferably comprises a thermocouple and / or a thermometer and / or an infrared thermometer. The temperature measuring device preferably comprises a plurality of thermocouples and / or a plurality of thermometers and / or a plurality of infrared thermometers. The temperature measuring device may preferably be designed as an analog or digital measuring device. It is preferably arranged on the side of the receiving portion or the sample facing away from the application member or aligned with the application member, that is, it determines the temperature of the back side of the sample, or when using a plurality of thermocouples and / or a plurality of thermometers and / or a plurality of infrared thermometers, determines the temperature of the back side of the sample and its distribution. The side facing away from the application member corresponds to the side of the sample facing away from the mass flow.

[0070] In another advantageous improvement, the application member is accommodated in the blind hole opening of the support element. The support element can be designed as a tube closed on one side and having a cup-shaped recess, in which the application member is accommodated and advantageously maintained in a precise position. The support element preferably has a locking device, which fixes the application member relative to the support element, thereby preventing the application member from falling from the support element. The locking device can be designed as a force-matching locking device (e.g., a clamping device) and / or a shape-matching locking device (e.g., one or more locking elements). The support element can be connected to the mount in a detachable or non-detachable manner. In the case of a detachable design, the support element is replaceable so that it can be replaced to match the application member. This means that the test device can be used universally and is not limited to a specific application member.

[0071] In an advantageous embodiment, the application member is adjustable relative to the base frame. This allows the application member to be positioned in a desired position relative to the base frame and its receptacle and ultimately relative to the sample, so that the mass flow can be applied to the sample in a desired manner. Preferably, the support element is held on the mount in an adjustable manner.

[0072] Preferably, the angle and / or distance of the application member relative to the chassis can be adjustable. Therefore, the application member can be adjusted so that the mass flow hits the sample orthogonally or at a certain angle. In addition, the distance between the application member and the chassis and its receptacle and therefore also the distance related to the sample that can be accommodated in the receptacle can be adjusted. Preferably, the support element is pivotally held on the frame. Alternatively or additionally, the support element can be held on the frame in a translationally displaceable manner so that the distance of the support element from the chassis can be adjusted and / or the support element can be adjusted to be parallel to the receptacle or the sample, so that when the angle of the application member is set, the application member is aligned with the receptacle or the sample, that is, so that the mass flow preferably hits the center of the sample. Preferably, the adjustable angle is preferably between 0° and 60°, particularly preferably between 0° and 45°. The 0° angle corresponds to a mass flow that flows orthogonally to the receptacle or the sample.

[0073] The test device preferably has a baffle, which is arranged on the side of the receiving portion facing away from the application member. The baffle is preferably made of a temperature-resistant and fire-resistant material, or includes such a material, such as steel or a ceramic material. The baffle should not be understood to mean that it must be made of a metal sheet. Alternatively, the baffle can also be referred to as a baffle element. The baffle is arranged in the path of the mass flow so that after the sample is burned through, the mass flow is guided in a predetermined direction by the baffle. This allows the mass flow to flow in the direction toward the exhaust device. Preferably, the baffle can be adjusted rotatably and / or translationally relative to the chassis. This allows the baffle to be adjusted to the set position of the application member so that the mass flow can flow in the desired direction, preferably in the direction toward the exhaust device. The baffle is preferably arranged to be force-decoupled from the force measuring device. This can ensure that the force measuring device only determines the force introduced into the sample, and the measurement will not be distorted by the mass flow hitting the baffle after the burn-through.

[0074] In an advantageous development, a sample holder is provided in which the sample can be accommodated, the sample holder being accommodated in the accommodation portion. The sample holder can be used to place the sample on the test device easily, conveniently and in a time-saving manner. The sample holder preferably has a mesh grid that can be placed over the sample. This ensures that the sample is securely arranged on the sample holder. The sample holder is preferably made of steel or aluminum or comprises such a material.

[0075] The mesh grid is preferably made of a material that is resistant to high temperatures and thermal shocks, preferably made of a fiber composite ceramic. The fiber composite ceramic is preferably a ceramic fiber reinforced ceramic. The fibers are advantageously oriented long fibers. Preferably, the mesh grid is a fabric of ceramic long fibers embedded in a ceramic matrix. The ceramic long fibers and / or the matrix are particularly preferably composed of metal oxide ceramic materials such as alumina or mullite. However, other ceramic materials for the fibers and / or the matrix are also possible. A large number of materials that are substantially suitable for both the matrix and the fibers are known in the prior art.

[0076] The mesh grid has been shown to withstand high thermal loads and is therefore particularly suitable for specimens containing organic insulating materials, which are often sources of fire and deflagration.

[0077] The mesh grid preferably has an area of ​​3 cm 2 Up to 25cm 2 The central opening between the two ends allows the mass flow to act on the sample without hindrance. Particularly preferably, in the case of low scattering mass flows (opening solid angle of the mass flow less than 10°), the central opening has a width of 3 cm. 2 Up to 7cm 2 The area between, especially 5cm 2 Particularly preferably, in the case of a scattered mass flow (mass flow opening solid angle greater than 10°), the central opening has a central opening of 10 cm 2 and 20cm 2 The area between.

[0078] Studies have shown that the scattered mass flow corresponds largely to the mass flow of a damaged cell. In particular, a distance between the application member and the specimen of between 40 mm and 60 mm has proven to be advantageous. A particularly advantageous arrangement has a mass flow with an opening solid angle of 40°, with a distance of 50 mm from the application member to the specimen and a central opening area of ​​16 cm2 of the mesh grid. 2 .

[0079] The opening solid angle is the opening angle of the mass flow cone and is twice the angle between the surface generatrix and the cone axis.

[0080] Preferably, the opening solid angle has a value between 3° and 10°. The grid is preferably fixed at a certain distance from the surface of the sample. This can be done, for example, by fixing the grid to a sample holder or to the sample in a floating manner. "Floating support" means that the grid is placed on the sample or at a certain distance from the sample. The grid is subjected to vertical downward forces, such as the weight of the grid and the components connected to the grid. The floating grid can also have vertical guides to allow the grid to move in the vertical direction, but fix it in the XY plane. Preferably, the distance between the grid and the sample surface is preferably between 1 and 5 mm.

[0081] In an advantageous embodiment, the sample holder is designed like a frame, so that the sample can be inserted therein. By means of this design, it can be ensured that when a mass flow is applied to the sample, the sample holder is not damaged and / or this has no or only a very small influence on the measurement result.

[0082] In an advantageous embodiment of the test device, a fixture may be provided for fixing the sample or sample holder to the receiving portion. The fixture may be switched between a fixed position and a release position, so that in the fixed position, the sample or sample holder is fixed relative to the receiving portion, and in the release position, the sample or sample holder can be accommodated in the receiving portion or removed therefrom. The fixture may be designed as a clamping device, such as a clamping rod or a tensioning rod. Alternatively or additionally, the fixture may be designed as a form-fitting locking device. In addition, the fixture may also be formed by screw elements such as screws, nuts or studs. The fixture ensures that the sample or sample holder does not move during the application of the mass flow. In an advantageous improvement, such a fixture may also be additionally provided on the sample holder to fix the sample relative to the sample holder.

[0083] In an advantageous improvement, the determination device may include a high-speed camera and / or an infrared camera and / or an acoustic measuring device. The infrared camera may be used to record thermal imaging and / or thermographic images of the sample. The infrared camera is aimed at the receiving portion or the sample that can be inserted into the receiving portion. Preferably, the infrared camera is aimed at the side of the receiving portion opposite to the application member or the sample that can be inserted into the receiving portion. This allows recording of thermal imaging or thermographic images of the back side of the sample. A high-speed camera (also referred to as a high-speed camera) may be used to record the image of the mass flow applied on the sample. For this purpose, the high-speed camera is aimed at the sample that can be accommodated in the receiving portion, preferably so that the image of the mass flow impacting the sample and / or the side of the sample that is opposite to the mass flow can be recorded. Preferably, the high-speed camera is arranged so that an image frequency of more than 30 images per second, particularly preferably more than 100 images per second, can be recorded. Preferably, the high-speed camera may include a filter device, the function of which is, for example, similar to welding goggles. The recording of the applied image is thereby improved. Two high-speed cameras may also be provided, one of which includes a filter device and is preferably aimed at the impact portion of the mass flow on the sample. The acoustic measuring device is preferably designed as a microphone. The microphone is particularly preferably designed as a directional microphone and is directed toward the application member or the test specimen. The test device can have two microphones, one of which is directed toward the application member and the other toward the test specimen. An advantage of the acoustic measuring device is that its measuring properties are not impaired by the generation of smoke during application.

[0084] In an advantageous development, the infrared camera and / or the high-speed camera and / or the acoustic measuring device can be adjustably mounted on the mount. Thus, the infrared camera and / or the high-speed camera can be optimally aligned with the impact portion of the mass flow.

[0085] In a further advantageous development, the test device has an air suction device and / or an exhaust fan device or can be connected to an air suction device and / or an exhaust fan device.

[0086] An extraction device can be used to extract the gases and fumes generated by the mass flow. For example, the extraction device can be arranged on the side of the receptacle or the specimen facing away from the mass flow, so that the mass flow can be at least partially extracted after burn-through. Alternatively or additionally, the extraction device can also be arranged on the side of the receptacle facing the mass flow, so that the fumes generated during the application can be extracted by the extraction device. This has the advantage that when using a high-speed camera, the field of view of the specimen remains clear during the application and is not affected by the fumes. Thus, by using a high-speed camera, the accuracy of the test can be further increased, for example when determining the time-dependent burn-through resistance.

[0087] The air extraction device can be part of the test device or can be connected to the test device, for example, by a hose. The air extraction device preferably comprises a wet scrubber and / or a HEPA filter (HEPA: High-Efficiency Particulate Air / Arrestance Filter). Such a wet scrubber is used to wash away components that are harmful to health and the environment, such as acids and fumes. The HEPA filter removes soot, fine particles and dust.

[0088] As an alternative or in addition to the extraction device, an exhaust fan device can be provided, which is preferably arranged on the side of the receiving portion facing the mass flow. The exhaust fan device is configured and arranged so that it removes the smoke generated during the application by means of a fluid flow, in particular an air flow. This has the advantage that when a high-speed camera is used, the field of view of the specimen remains clear during the application and is not affected by the smoke. As a result, the accuracy when determining the time-dependent burn-through resistance using a high-speed camera can be further increased. The size of the fluid flow must be set so that its influence on the mass flow during the application is negligible and technically negligible.

[0089] The exhaust blower device may preferably comprise a compressed air lance for directing the fluid flow, which compressed air lance may be connected to a compressed air hose for connecting the compressed air lance to the pneumatic system.Alternatively or additionally, the exhaust blower device may comprise a blower and / or a compressor.

[0090] In a further advantageous development of the test device according to the invention, the force measuring device is at least partially surrounded by a shield or an encapsulation. Particularly preferably, the force measuring device is completely surrounded by the encapsulation, wherein the electrical lines are passed through the encapsulation in a sealed manner. Preferably, the shield or the encapsulation is a sealed thermal encapsulation. In this way, negative interfering effects of gases and particles emitted by the mass flow on the force measuring device are at least greatly reduced, so that distortions of the force measurement are offset, thereby further improving the measuring accuracy of the test device.

[0091] In an advantageous improvement, a jet velocity measuring device may be provided for determining the jet velocity of the mass flow. The jet velocity measuring device may also be referred to as a flow velocity measuring device. Preferably, the jet velocity measuring device is preferably a Doppler spectrometer. Preferably, the jet velocity measuring device may be arranged between the receiving portion and the application member, so that the jet velocity may be spatially determined before the mass flow strikes the sample. Alternatively or additionally, the jet velocity measuring device or another jet velocity measuring device may be arranged on the side of the receiving portion or the sample facing away from the application member. Thus, the jet velocity may be determined after the sample has been burned through.

[0092] In an advantageous development, the application member is designed to provide pulses between 1 Newton-second (Ns) and 250 Ns, particularly preferably between 1 Ns and 100 Ns.

[0093] In a further advantageous development, the application means is designed to provide the mass flow within a flow duration of between 2 seconds and 30 seconds, particularly preferably between 5 seconds and 25 seconds. It can thereby be ensured that the mass flow is applied to the specimen for a sufficient time so that the time-dependent burn-through resistance can be determined and that the mass flow does not continue to flow for an unhelpful time after the burn-through. In other words, the flow duration can be adapted to the properties of the specimen or to the flow duration of the fire to be simulated, for example thermal runaway of a lithium-ion battery.

[0094] Preferably, the fuel of the application member is selected so that the mass flow has a specific flow rate, momentum, temperature, opening angle and chemical composition. The fuel supply can be adjusted according to the demand curve and supplied to the application member. Therefore, it is conceivable and possible to adjust the fuel and its amount before or even during the application. Thus, the mass flow can be adjusted according to the expected test parameters.

[0095] In a preferred embodiment, the application member has means designed to add particles to a mass flow. The mass flow is preferably a gaseous flow. In this way, for example, the force introduced into the sample by the mass flow can be adjusted.

[0096] Preferably, the test device can include a mass measuring device for determining the mass of the fuel applied to the member. The mass measuring device can be designed, for example, in the form of a scale. Alternatively, the volume of the fuel can also be determined, so that the mass can be determined from this.

[0097] In a favorable improvement example, the application member has a nozzle or can be connected to the nozzle. The nozzle preferably has a nozzle outlet channel, which has a predetermined length, a predetermined opening cross section and a predetermined opening angle. Therefore, the nozzle has a predetermined nozzle geometry at the outlet end. The nozzle geometry can be selected so that different emission characteristics can be set using the same type of application member, for example, the impact area of ​​the mass flow and / or the impact velocity and the momentum of the mass flow can be set. The nozzle geometry is determined, for example, by the length of the nozzle outlet channel (corresponding to the length of the outlet cone also referred to as the outlet cone), the opening cross section (the diameter of the outlet opening) and the opening angle (the cone opening angle of the outlet). Thus, the pulse and the impact area can be specially adjusted.

[0098] The opening angle of the nozzle outlet can be selected according to the desired discharge characteristics. For example, the opening angle can also be zero, so that the nozzle outlet is formed by a cylindrical channel. The opening angle preferably has a value between 45° and 135°. The opening angle corresponds to twice the angle between the surface generatrix and the cone axis.

[0099] Due to this adaptability of the nozzle geometry, the emission characteristics of different lithium-ion batteries in the event of a failure (also called thermal runaway) can be simulated, in particular with regard to the opening angle of the jet cone (exit cone), the nozzle outlet channel), the hot gases and particles, the temperature at the impact point, the overall mass impulse at the impact area, the mass impulse per unit area, the jet velocity.

[0100] Alternatively, the nozzle can also be arranged on a support element for holding the application member. Thereby, nozzles with different geometries can be easily attached to the support element and thus the mass flow of the application member can be guided through them. The nozzle can have an adjustable nozzle geometry, which is preferably also adjustable during application. Thereby, during application, the flow characteristics of the mass flow can be further uniformed.

[0101] In an advantageous embodiment of the test device according to the invention, the application member is designed as a rocket propellant charge, an acetylene burner with mass feed, a flame spray device, a galvanic cell or a plasma spray device. A rocket propellant charge may also be referred to as a rocket or a rocket engine.

[0102] The rocket propellant charge is preferably a solid composite propellant charge. These solid composite propellant charges have proven to be particularly advantageous because they provide a more uniform mass flow over the application time and improve repeatability due to very small tolerances between individual thrusters.

[0103] The rocket propellant charge can preferably be activated by electrical ignition. This is simple, practical, and can be achieved without much effort.

[0104] In an advantageous development, the galvanic cell is designed as a secondary battery, also known as an accumulator. The galvanic cell comprises at least one battery cell. The galvanic cell is particularly preferably designed as a lithium-ion battery. Due to this design of the application component, the specimen can be tested under quasi-real conditions.

[0105] In an advantageous refinement, the galvanic cell is preferably arranged such that the mass flow flows out of the galvanic cell against gravity. This offers the advantage that, compared to a suspended arrangement, with this upright arrangement no or almost no flammable liquid electrolyte can escape from the galvanic cell, thus counteracting uncontrolled combustion or even deflagration.

[0106] In an advantageous improvement, the test device and / or the determination device has a data acquisition device. For example, the data acquisition device can be designed as a computer. The data acquisition device is preferably electrically connected to at least one of the aforementioned measuring devices or all of the aforementioned measuring devices and is configured to record the measurement signals of the measuring devices.

[0107] In an advantageous development, the shielding component and / or the deflecting device are arranged between the application component and the receptacle.

[0108] Due to the shielding element arranged in this way, it can be ensured that, in particular at small distances between the application element and the specimen, the application element is not damaged or destroyed by reflections of the mass flow. The shielding element is preferably made of a high temperature and thermal shock resistant material, preferably a fiber composite ceramic.

[0109] The shielding member can preferably be designed as a perforated plate (Lochblende) with holes that allow the mass flow to flow through. The perforated plate is preferably mounted directly on the application member so that the holes are designed to correspond to the nozzles of the application member. Alternatively, the shielding member can be arranged at a certain distance from the application member. The size of the hole is set so that the mass flow can flow unimpeded. In a particularly advantageous refinement, the mass flow hits the specimen at a certain angle (i.e. slightly inclined) so that a large part of the reflection of the mass flow hits the shielding member and the application member is even better protected.

[0110] By means of such a deflection device, the mass flow can be deflected accordingly during propagation. The deflection device is preferably arranged between the application member and the specimen, in particular, the deflection device is arranged on the side of the specimen facing the application member and is located in the impact portion. The deflection device can be fixed to the specimen, for example, by means of fixing devices such as screws. It has been shown that it is particularly advantageous to design the deflection device in a pyramidal or wedge-shaped manner. Due to such a design of the deflection device, the so-called thermal runaway of lithium-ion batteries can be simulated more realistically than in the prior art. This thermal runaway causes the metal battery components to be ejected quickly and in large quantities, thereby forming a pyramid-shaped deposit, which accordingly deflects the fast, hot gas. This represents an emission characteristic that is completely different from a vertical impact jet. Therefore, the described deflection device can be simulated very realistically using the test device according to the invention.

[0111] By changing the angle of the deflector, the damage intensity can be adjusted and set, wherein at an angle of 45° the main intensity of the mass flow is parallel to the sample surface. An angle between the jet direction and the surface normal of the deflector is advantageously between 30° and 45°.

[0112] In an advantageous development, the steering device is made of a ceramic material or a metallic material, in particular steel, or comprises a ceramic material or a metallic material.

[0113] The deflection device is preferably designed as a wedge having two surfaces for guiding the mass flow, wherein the angle of one surface relative to the sample surface is equal or different than the angle of the second surface relative to the sample surface. As a result, the conditions prevailing in reality can be reproduced more accurately on the test device.

[0114] The testing device is preferably suitable for executing the above-mentioned method for testing a sample according to the present invention and its improved examples, whereby the testing device may also preferably have the aforementioned improved examples.

[0115] It is noted that the features of the specified refinements and advantageous refinements can be freely combined with one another as far as is technically possible, even if this is not explicitly stated in the text. This applies in particular to claims that go beyond the scope of the device and method claim categories. BRIEF DESCRIPTION OF THE DRAWINGS

[0116] Further advantages and features of the method according to the invention and of the testing device according to the invention emerge from the following embodiments, which will be explained in more detail with reference to the drawing.

[0117] Figure 1 shows a schematic diagram of a first embodiment of a test apparatus according to the present invention before applying a high-speed thermal mass flow to a specimen,

[0118] Figure 2 shows a schematic diagram of a first embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0119] Figure 3 A schematic diagram showing a first embodiment of a testing device according to the present invention after burning through of a test specimen,

[0120] Figure 4a shows a schematic diagram of a force-time diagram having a force-time curve generated by carrying out the method according to the invention,

[0121] Figure 4b A schematic diagram of a force-time diagram with a force-time curve is shown, wherein the specimen survives the application without burning through,

[0122] Figure 5 shows a schematic diagram of a second embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0123] Figure 6 A schematic diagram showing a second embodiment of a testing device according to the present invention after burning through of a test specimen,

[0124] Figure 7 shows a schematic diagram of a third embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0125] Figure 8 shows a schematic diagram of a fourth embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0126] Fig. 9 shows a schematic diagram of a fifth embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0127] Fig.10 shows a schematic diagram of a sixth embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a test specimen,

[0128] Fig.11 shows a schematic diagram of a seventh embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a test specimen,

[0129] Fig.12 shows a schematic diagram of an eighth embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0130] Fig.13 shows a schematic diagram of a ninth embodiment of a test apparatus according to the present invention during application of a high-speed thermal mass flow to a specimen,

[0131] Fig.14 A schematic cross-sectional view of a nozzle for adjusting the discharge characteristics of a mass flow is shown. DETAILED DESCRIPTION

[0132] In the individual figures, identical components are always provided with the same reference symbols and are therefore usually named or mentioned only once.

[0133] Figures 1 to 3 A first embodiment of a test device 10 according to the invention is shown. The test device 10 is used to test a test specimen 50 using the method according to the invention. The test device 10 has a chassis 30; the chassis 30 has a receptacle 32 and the test specimen 50 is received directly in the receptacle 32. The application component 20 designed as a rocket engine is held on a fixed, immovable first support 98, which is schematically shown here as a clamp. Figure 1 In the process, the application member 20 has not yet been ignited, so in Figure 1 FIG. 5 shows the test apparatus before applying the high-speed thermal mass flow 22 to the sample 50. The high-speed thermal mass flow is referred to as mass flow hereinafter. Figure 2 It can be seen that the application member 20 is directed toward the specimen 50 such that the mass flow 22 impinges on the specimen 50 .

[0134] Furthermore, the test device 10 has a determination device designed as a force measuring device 40, which is operatively coupled to the base frame 30. The force measuring device 40 is designed as a force measuring sensor and is accommodated in an encapsulating housing 42. The force measuring device 40 is held on an immovable second support 99 so that the force F introduced into the specimen 50 by the mass flow can be determined. Figures 1 to 3 In the first embodiment of the test device 10 shown, the plate-shaped specimen 50 is directly received in the receiving portion 32. To this end, the receiving portion 32 is designed as an edge portion of the chassis defining a recess 33, which is stepped so that the specimen 50 can be securely inserted therein and at the same time, as shown in FIG. Figure 2 When the mass flow 22 is applied to the sample 50 as shown, the support of the sample 50 is ensured, so that the force flow is introduced from the sample 50 into the base frame 30 via the receiving portion 32, and the base frame 30 further transmits the force flow to the force measuring device 40. The sample 50 has a front side 51 and a back side 52, wherein the front side 51 faces the application member 20 and the back side 52 faces away from the application member 52. The edge portion of the back side 52 of the sample 50 rests on the receiving portion 32, wherein the largest area of ​​the back side 52 is not in contact with the receiving portion 32, that is, there is no contact.

[0135] Here, the chassis 30 is schematically designed as a pot-shaped component, preferably made of steel, having a base 34 by which the chassis 30 stands on the force measuring device 40 and is thus effectively coupled to the force measuring device 40 , thereby ensuring a force flow from the chassis 30 to the force measuring device 40 .

[0136] Figure 2 The graph shows that during the application of mass flow 22 to the sample 50 Figure 1 The supply device 20 provides a mass flow 22 after its electrical ignition within a flow duration predetermined by the characteristics of the application component 20, which is designed here as a rocket engine with a solid composite thruster and is also referred to as an application component. The application component 20 is aligned with the test specimen 50 so that the mass flow 22 hits the test specimen 50 in an impact portion 55 on the front side 51 and introduces heat and force F into the test specimen. The impact portion 55 can also be referred to as an impact point. The application component 20 ejects the mass flow 22 and presses it onto the test specimen 50, thereby introducing the force F via the receptacle 32 into the chassis 30 coupled to the force measuring device 40 via the base portion 34, so that the force F introduced into the test specimen 50 by the mass flow 22 is determined by the force measuring device.

[0137] The method according to the invention can be used to determine the time-dependent burn-through resistance of a test specimen 50 by means of a determination device which comprises a force measuring device. Figure 2As shown, a high-speed thermal mass flow 22 is applied to the specimen 50 and the force F acting on the specimen 50 due to the application is continuously determined by the force measurement device 40 to determine the time period ts between the start of the application and the occurrence of a force drop based on burn-through of the specimen 50.

[0138] Figure 3 It shows that after the sample 50 is burned through, Figure 1 and 2 The test device 10 according to the present invention is shown. Figure 3 The result of the burn-through of the specimen 50 can be seen. Due to the heat input, the mass flow 22 burns through the specimen 50 and produces an opening 58 therein. Since the mass flow 22 can now flow through the burn-through opening 58 of the specimen 50, no or only very little force is introduced into the specimen 50, so that there is a force drop, which is determined by the force measuring device 40. Thus, the time period ts between the start of the application and the occurrence of the force drop due to the burn-through of the specimen 50 can be determined by the described method according to the invention. From Figure 4a This can be better seen in the force-time diagram of .

[0139] Figure 4a A schematic force-time diagram with a force-time curve is shown, which is obtained, for example, by Figures 1 to 3 and Figures 5 to 8 One of the test devices according to the invention shown in FIG. 1 is used to determine the force F introduced into the test specimen 50 by the mass flow 22 over a time t. This force-time curve can be determined by a force measuring device 40 .

[0140] At the starting time point t0, which indicates the start of applying the mass flow 22 to the specimen 50, there is a sharp increase in force up to a maximum force F2. The force then drops to force F1, so that the force introduced by the mass flow 22 remains relatively constant from time point t1 to time point t2. The time period between time points t0 and t1 shows the starting pulse of the application component 20 designed as a rocket engine. After the starting pulse occurs, the application component designed as a rocket engine provides a constant mass flow 22, which uniformly and continuously introduces heat and force in the specimen 50, so that from time point t1 to time point t2, a substantially constant force acts on the specimen 50. At time point t2, the specimen 50 reaches its time-dependent burn-through resistance, so it starts to burn through at time point t2. For example, as Figure 3As shown, since the mass flow 22 burns out the opening 58 in the specimen 50 and can thus flow therethrough, and thus no force or very small force is introduced into the specimen 50, there is a quasi-sharp drop in force from the force F1 to the force F3 from the beginning of the burn-through corresponding to the time point t2. When the burn-through of the specimen ends, the drop in force to the force level of the force F3 ends at the time point t3. In other words, the burn-through time point t2 is determined by the force jump between the force level (force plateau) of the force F1 and the force level (force plateau) of the force F3. Therefore, the time period ts can be determined as a measure of the burn-through resistance of the relevant time between the start t0 of the application and the occurrence of the force drop based on the burn-through of the specimen 50 at the time point t2. Therefore, the method according to the present invention can be used to determine the burn-through resistance of the relevant time (i.e., the time period ts). Since the mass flow 22 continues to flow for a certain time even after the burn-through and flows over the edge of the opening 58, even after the burn-through, a small force F3 is still introduced into the specimen 50. The following relationship holds true: F2>F1>F3>0. Starting from time t4, the force F3 drops to a value of 0 at time t5 because of a propellant (fuel) shortage leading to a so-called burnout of the application member 20 designed as a rocket engine.

[0141] Figure 4b A schematic force-time diagram is shown with a force-time curve obtained by Figures 1 to 3 and Figures 5 to 8 The force F introduced into the test specimen 50 by the mass flow 22 is determined over a time t, in which case the test specimen 50 does not burn through but survives the application of the mass flow 20. Such a force-time curve can be determined by the force measuring device 40.

[0142] At the start time point t0, which represents the beginning of the application of the mass flow 22 to the specimen 50, there is a sharp increase in force up to a maximum value F2. The force then drops to force F1, so that the force introduced by the mass flow 22 remains relatively constant from time point t1 to time point t4. The time period between time points t0 and t1 shows the starting pulse of the application component 20 designed as a rocket engine. After the start pulse occurs, the application component designed as a rocket engine provides a constant mass flow 22, which uniformly and continuously introduces heat and force in the specimen 50, so that from time point t1 to time point t4, a substantially constant force acts on the specimen 50. Starting from time point t4, the force drops from force F1 to a value of 0 at time point t5, because the fuel is exhausted resulting in the so-called burnout of the application component 20 designed as a rocket engine. With Figure 4aIn contrast to the force curve in , sample 50 did not burn through, so it can be seen that there was no force drop from F1 to force F3>0 due to burn through. Sample 50 survived the entire application time (t0 to t5) without burning through. Therefore, the time period ts>t5-t0.

[0143] Figure 5 and 6 A second embodiment of a testing device 10 according to the present invention is schematically shown, wherein: Figure 5 A second embodiment is shown during application of a high-speed thermal mass flow to a specimen 50, and Figure 6 The second embodiment is shown after burn-through of the specimen.

[0144] The structure of the second embodiment is based on the test device 10 of the first embodiment, wherein the application member 20, the force measuring device 40 and the receiving portion 32 of the chassis 30 and the test specimen 50 shown correspond to those components of the test device of the first test device 10 of the first embodiment, and therefore no repeated description is given to avoid redundancy. All features described with respect to the similar components mentioned can be transferred.

[0145] In this embodiment, the application member 20 is not supported on a fixture, but on a support beam 73 of a frame 70. The frame 70 can also be referred to as a frame or a support unit. The force measuring device 40 is also mounted on the frame 70 and supported thereon, i.e., supported on a support foot 71 of the frame 70.

[0146] The base frame 30 is schematically designed as a pot-shaped component, which has a base part 34, by means of which the base frame 30 stands on the force measuring device 40 of the determination device and is thus effectively coupled to the force measuring device, thereby ensuring a force flow from the base frame 30 to the force measuring device. The base frame 30 can thus be moved at least to a small extent relative to the support frame 70, so that the force F introduced into the test specimen 50 by the mass flow 22 can be determined. In a variant that is not shown, a guide device can be provided between the support frame and the base frame, so that the base frame is guided in a manner that it can be moved in one direction.

[0147] A baffle 60 is arranged in the base frame 30 and is arranged at one end of a support arm 72 of the mount 70. The support arm 72 extends through a hole-shaped recess 35 in the side wall of the base frame 30, wherein the support arm 72 protrudes through the hole-shaped recess 35 with a gap, thereby ensuring force decoupling of the baffle 60 from the base frame 30 and thus from the measuring device 40. Figure 6It can be clearly seen that the baffle 60 is inclined relative to the front side 51 of the specimen 50, i.e. arranged at a certain angle, so that the mass flow 22 flowing through the opening 58 of the specimen 50 in the event of a burn-through is directed toward the exhaust device. The inclination of the baffle relative to the front side 51 of the specimen 50 is preferably between 30° and 60°. The air inlet 65 of the exhaust device is shown here in a schematic manner. This air inlet 65 passes through another recess in the other side wall of the base frame 30.

[0148] The infrared camera 84 is arranged on the support arm 72, which is aimed at the back side 52 of the sample 50 and records a thermal image of the back side 52 of the sample 50 when the mass flow 22 is applied to the sample 50. The infrared camera 84 is attached to the support arm 72 in an adjustable orientation. The infrared camera 84 forms part of the determination device.

[0149] Furthermore, a temperature measuring device 81 is arranged on the rear side 52 of the test specimen 50 and adjacent to the impact portion 55. The temperature measuring device 81 is designed as a thermocouple and is bonded to the rear side 52 of the test specimen.

[0150] A first high-speed camera 82 with a filter 821 and a second high-speed camera 83 are attached to the mount 70, and the orientation of each of them is adjustable. The high-speed cameras 82, 83 form part of the determination device. The first high-speed camera 82 is aimed at the impact part 55 of the mass flow 22. The second high-speed camera 83 is aimed at the mass flow 22 and its impact part 55 and the sample 50. However, it can also be arranged so that the application member 20 is also recorded. The two high-speed cameras obtain a video record of the application process.

[0151] Figure 7 A third embodiment of a test apparatus 10 according to the invention is schematically illustrated, showing the third embodiment during application of a high velocity thermal mass flow 22 to a test specimen 50 .

[0152] The structure of the third embodiment is based on the test device 10 of the second embodiment, wherein the application member 20, the force measuring device 40 and the receiving portion 32 of the chassis 30 correspond to those of the second embodiment, so they are not described repeatedly to avoid redundancy. All features described with respect to the similar components mentioned can be transferred.

[0153] The structure and function of the seat frame 70 are similar to Figure 5 and 6 The support frame 70 of the second embodiment, in which the support beam 73 carrying the application member 20 can be adjusted in the height direction H by a first adjustment device 77. Therefore, the distance between the application member 20 and the receiving portion 32 and thus the distance between the application member 20 and the test specimen 50 can be adjusted.

[0154] The application member 20 is accommodated in the blind hole opening of the support element 90. The support element 90 is designed as a tube closed on one side. The support element 90 has a locking device (not shown) that fixes the application member 20 relative to the support element 90, thereby preventing the application member 20 from falling from the support element 90.

[0155] The support element 90 is pivotally held in the pivot direction W by means of a lockable joint 92 on the support beam 73 of the mount 70, so that the angle of the application member 20 relative to the receptacle 32 and therefore relative to the specimen 50 is adjustable, so that the mass flow 22 can also strike the front side 51 of the specimen 50 at a certain angle. The adjustable angle is preferably between 0° and 60°, particularly preferably between 0° and 45°. Figure 7 As shown, an angle of 0° corresponds to a mass flow 22 which flows orthogonally to the receptacle 32 or to the sample 50 .

[0156] The support element 90 is held in the vertical direction V in a translational manner by a second adjustment device 78 on the support beam 73 of the frame 70, so that the support element 90 can be adjusted in a manner parallel to the receptacle 32 or the sample 50. Therefore, according to the set angle of the support element 90 and the application member 20 accommodated therein, adjustment can be made so that the mass flow 22 is guided to the receptacle 32 or the sample 50, preferably so that the mass flow 22 hits the center of the sample 50.

[0157] The first adjusting device 77 can be designed as a manual, electric, pneumatic or hydraulic adjusting device. The second adjusting device 78 can also be designed as a manual, electric, pneumatic or hydraulic adjusting device.

[0158] A first high-speed camera 82 with a filter 821 and a second high-speed camera 83 are attached to the mount 70, and the orientation of each of them is adjustable. The first high-speed camera 82 is aimed at the impact part 55 of the mass flow 22. The second high-speed camera 83 is aimed at the mass flow 22 and its impact part 55 and the specimen. However, it can also be arranged so that the application member 20 is also recorded. The two high-speed cameras obtain an image record of the application and form part of the determination device for testing the specimen.

[0159] The infrared camera 84 is arranged on the support arm 72 of the mount 70, and is constructed and arranged as in the second embodiment.

[0160] The baffle 60 is arranged in the base frame 30 and is adjustable in position and angular orientation at one end of a support arm 72 of a mount 70. The support arm 72 extends through a hole-shaped recess in the side wall of the base frame 30 so that the recess is force-decoupled from the base frame 30. The baffle 60 is inclined relative to the front side 51 of the specimen 50 so that the mass flow 22 flowing through the opening in the specimen 50 in the event of a burn-through is directed to the exhaust device. Preferably, the inclination of the baffle relative to the front side 51 of the specimen 50 is adjustable between 30° and 60°. An air inlet 65 of the exhaust device is schematically shown here. The air inlet 65 passes through another recess in the other side wall of the base frame 30.

[0161] Furthermore, a temperature measuring device 81 is arranged on the back side 52 of the test specimen 50 and adjacent to the impact portion 55. The temperature measuring device 81 is designed as a thermocouple and is bonded to the back side 52 of the test specimen.

[0162] In contrast to the first two embodiments, the sample 50 is not directly accommodated in the accommodation portion 32 of the base frame 30, but is indirectly accommodated in the accommodation portion 32 of the base frame 30. For this purpose, a sample holder 38 for accommodating the sample 50 is provided, and the sample holder 38 is accommodated in the accommodation portion 32. The sample holder 38 preferably has a mesh grid 59, which is placed on the sample 50 like a cover. Therefore, the sample 50 is firmly held on the sample holder 38. The sample holder 38 is designed in a frame shape so that the sample 50 can be inserted therein.

[0163] The first fixing device 37 is provided for fixing the sample holder 38 in the receiving portion 32 and is designed as a clamping lever. The fixing device 37 can be switched between a fixing position and a release position, so that in the fixing position the sample holder 38 is fixed relative to the receiving portion 32, and in the release position the sample holder 38 can be received in the receiving portion 32 or removed therefrom.

[0164] Furthermore, a second fixing device 39 is provided for fixing the sample 50 on the sample holder 38 , which is designed as a screw element and is shown schematically.

[0165] In addition, the test device 10 has a data acquisition device 100, which is designed as a computer and can also be called a measurement computer. The data acquisition device 100 is electrically connected to all the above-mentioned measuring devices and is configured to record the measurement signals from the measuring devices. That is, the data acquisition device 100 is connected to the force measuring device 40, the temperature measuring unit 81, the first high-speed camera 82, the second high-speed camera 83 and the infrared camera 84 via a data line 101. The data line 101 can be designed as a data bus.

[0166] In a variant that is not shown, it is also conceivable and possible for the first adjusting device 77 and the second adjusting device 78 to each have a position sensor and / or to be controlled by a data acquisition device in the case of a non-manual design.

[0167] Furthermore, the data acquisition device 100 can be used to electrically ignite the application component 20 and thus initiate the recording of measurement results.

[0168] Figure 8 The fourth embodiment of the test apparatus 10 according to the present invention is shown during application of a high velocity thermal mass flow 22 to a specimen 50 .

[0169] This fourth embodiment corresponds largely to Figures 1 to 3 The first embodiment shown in , but supplemented by a shielding member 24 designed as a perforated plate, which is arranged between the application member 20 and the receiving portion 32. In addition, in contrast to the first embodiment, the mass flow 22 does not hit the specimen 50 completely vertically because the chassis 30 is slightly inclined. Therefore, most of the reflections of the mass flow 22 hit the shielding member 24, and the application member 20 is sufficiently well protected from damage. The shielding member 24 designed as a perforated plate 24 is made of a material resistant to high temperatures and thermal shocks. The shielding member 24 has a hole 26 through which the mass flow 22 can flow. The shielding member 24 designed as a perforated plate is directly mounted on the application member 20, so that the hole 26 is designed to correspond to the nozzle of the application member 20. In an alternative embodiment not shown, the shielding member can be arranged at a certain distance from the application member. In this case, the size of the hole is set so that the mass flow can flow unimpeded. All other aspects of the test device 10 of the fourth embodiment correspond to the first embodiment, and in order to avoid redundancy, they are not repeated here.

[0170] Fig. 9 A schematic diagram of a fifth embodiment of a testing device according to the invention is shown during application of a mass flow to a test specimen.

[0171] The structure of the fifth embodiment is based on the test device 10 of the second embodiment, but the only difference is that Fig. 9A fifth embodiment of the invention comprises an acoustic measuring device 85 designed as a microphone. By means of the acoustic measuring device 85, recording can be performed during the application of the mass flow 22 to the specimen 50, so that additional information about the application process can be determined. For example, the ignition time point t0 of the application member 20 can be accurately determined by means of the acoustic measuring device 85. In addition, the time point when the specimen 50 burns through can also be determined by means of the acoustic measuring device. Therefore, the acoustic measuring device is part of the determination device. This provides redundancy for other similar measuring devices such as force measuring devices and cameras, which are also based on different measurement principles. In addition, the acoustic measuring device has the advantage that, unlike a camera, its measuring performance is not impaired by the generation of smoke during application. The acoustic measuring device can also form a determination device without other measuring devices. In other words, the burn-through resistance of the specimen in relation to time can be determined solely by means of the acoustic measuring device.

[0172] Figure 5 All other described features of the second exemplary embodiment in the Fig. 9 The fifth embodiment of the invention.

[0173] Fig.10 A schematic diagram of a sixth embodiment of a test apparatus 10 according to the present invention is shown during application of a high velocity thermal mass flow 22 to a specimen 50 .

[0174] The test device 10 comprises a base frame 30 with a receptacle 32, in which a sample 50 is directly received. The receptacle 32 is designed as an edge portion of the base frame 30 that defines a recess 33, wherein the edge portion is stepped so that the sample 50 can be firmly inserted therein. The application member 20, which is designed here as a galvanic cell, in particular as a lithium-ion cell, is held on a fixed, immovable first support 98, which is schematically shown here as a support frame 79 and is fixed to the fixture. The support frame 79 extends through a hole-shaped recess 35 in the side wall of the base frame 30, and the support frame 79 protrudes through the hole-shaped recess 35 in a manner that there is a gap, thereby ensuring a force decoupling of the application member 20 from the base frame 30 and therefore from the measuring device 40.

[0175] The mass flow 22 is provided by the application member 20. The application member 20 is aligned with the test specimen 50 so that the mass flow 22 hits the test specimen 50 in the impact portion 55 of the front side 51 and introduces heat and force F therein. The impact portion 55 may also be referred to as an impact point. The application member 20 ejects the mass flow 22 and presses it onto the test specimen 50. This transfers the force F via the fixing device 37 designed as a screw and the receiving portion 32 to the chassis 30 coupled to the force measuring device 40 via the base 34, so that the force F introduced into the test specimen 50 by the mass flow 22 is determined by the force measuring device.

[0176] The method according to the invention can be used to determine the time-dependent burn-through resistance of a test specimen 50. Fig.10 As can be seen in FIG. 1 , the high-speed heat mass flow 22 from the galvanic cell 20 is applied to the specimen 50, and the force F acting on the specimen 50 due to the application is continuously determined by the force measuring device 40, thereby determining the time period ts between the start of the application and the occurrence of the force drop based on the burn-through of the specimen 50. Additionally or alternatively, the determination device may also include other or additional measuring devices.

[0177] The application member 20 is arranged in the base frame 30 so that the mass flow 22 flows out of the galvanic element against the force of gravity, i.e. upwards. This offers the advantage that in this upright arrangement, compared to a suspended arrangement, no or almost no flammable liquid electrolyte can escape (leak) from the galvanic cell 20 and thus uncontrolled combustion or even deflagration is counteracted.

[0178] The test device 10 has a force measuring device 40 operatively coupled to the base frame 30. The force measuring device 40 is accommodated in an encapsulating housing 42. The force measuring device 40 is held on an immovable second support 99 so that a force F introduced into the test specimen 50 by the mass flow can be determined.

[0179] Furthermore, a temperature measuring device 81 is arranged on the back side 52 of the test specimen 50 adjacent to the impact portion 55, so that the temperature of the test specimen 50 can be determined during the application. The temperature measuring device 81 is designed as a thermocouple.

[0180] Fig.11 A schematic diagram showing a seventh embodiment of a test apparatus according to the present invention during application of a high velocity thermal mass flow to a specimen.

[0181] The structure of the seventh embodiment is based on the test device 10 of the second embodiment, but the only difference is that Fig.11 The seventh embodiment comprises an exhaust fan device 67. The exhaust fan device has a compressed air spray gun 69, which is fixed in a mount 70 and is connected to a compressed air hose 68, which is connected to a compressor (not shown). The exhaust fan device 67 is configured and arranged so that it removes the smoke generated during application by an air flow. The advantage of this is that when a high-speed camera is used, the field of view of the specimen remains clear during application and is not affected by the smoke. Therefore, the test accuracy of the specimen can be further improved, in particular the accuracy when using a high-speed camera to determine the burn-through resistance over time. The size of the fluid flow must be set so that its influence on the mass flow during application is negligible and technically negligible.

[0182] Figure 5 All other described features of the second exemplary embodiment can be transferred without restriction to Fig.11The seventh embodiment of the invention.

[0183] Fig.12 A schematic diagram of an eighth embodiment of a test apparatus according to the present invention is shown during application of a high velocity thermal mass flow to a specimen.

[0184] The structure of the eighth embodiment is based on the test device 10 of the seventh embodiment, but the only difference is that Fig.12 The eighth embodiment of the invention does not include a force measuring device. The determination device for determining the time-dependent burn-through resistance here comprises high-speed cameras 82 and 83 which determine the time period ts using the method according to the invention.

[0185] Fig.11 All other combinations of the seventh embodiment Figure 5 The features described in the various aspects of the second embodiment can be transferred to Fig.12 The eighth embodiment of the present invention.

[0186] Fig.13 A schematic diagram of a ninth embodiment of a testing apparatus according to the present invention is shown during application of a high velocity thermal mass flow to a specimen.

[0187] The structure of the ninth embodiment is based on the test device 10 of the first embodiment, but the only difference is that Fig.13 The ninth embodiment includes a steering device 25 .

[0188] from Fig.13 It can be clearly seen that the mass flow 22 can be turned accordingly when it propagates by the steering device 25 designed as a wedge. The steering device 25 designed as a wedge is arranged between the application member 20 and the sample 50, specifically between the application member and the side 51 of the sample 50 facing the application member 20. The steering device 25 is fixed to the sample by screws not shown. The steering device 25 is made of steel. The steering device 25 designed as a wedge has two surfaces for guiding the mass flow, wherein the angle of one surface relative to the sample surface is equal to the angle of the second surface relative to the sample surface. Thus, the conditions prevailing in reality can be reproduced more accurately on the test device. When the mass flow 22 hits the steering device 25, the mass flow is basically halved and turned laterally accordingly. The effect of the steering device acts like a plow. The steering device 25 can be easily combined into other embodiments.

[0189] Fig.14A schematic longitudinal cross-sectional view of a nozzle 21 is shown. The nozzle 21 can be combined with all previously shown embodiments in order to adjust the discharge characteristics of the mass flow accordingly. The nozzle 21 has a conical or tapered nozzle outlet channel 211, which has a predetermined length 212, a predetermined opening cross section 213 and a predetermined opening angle α. The opening cross section 213 here represents the inlet cross section from the supply line to the nozzle outlet channel. Due to the cone angle, the final outlet cross section can be easily determined by calculation. The wall of the outlet channel can be curved, for example convex or concave.

[0190] In principle, the measuring device, the camera and all other advantageous developments shown in the other exemplary embodiments can also be transferred to Fig.10 The test setup is shown.

[0191] Reference numerals list 10 Test equipment 20 Apply components 21 Nozzle 22 Mass Flow 24 Shielding member 25 Steering device 26 holes 30 Base 32 Accommodation 33 Notch 34 Base 35 Hole-shaped notch 37 First Fixing Device 38 Specimen holder 39 Second Fixing Device 40 Force measuring device 42 Package Shell 50 samples 51 front 52 dorsal 55 Impact part 58 Opening 59 mesh grille 60 Baffle 65 Air inlet of the air extraction device 67 Exhaust fan device 68 Compressed air hose 69 Compressed air spray gun 70 Seat 71 Support feet 72 Support arm 73 Support beam 77 First adjustment device 78 Second adjustment device 79 Support frame 81 Temperature measuring device 82 First high-speed camera 821 Filter 83 Second High Speed ​​Camera 84 Infrared Camera 85 Acoustic Measurement Device 90 Support element 92 Connectors 98 First support 99 Second support 100 Data acquisition device 101 Data Cable 211 Nozzle outlet channel 212 Length 213 Opening cross section α Opening angle t0 start time ts Time period as a measure of the time-dependent burn-through resistance.

Claims

1. A method for thermomechanical testing of a specimen (50), characterized in that A high velocity thermal mass flow (22) is applied to the sample (50).

2. The method according to claim 1, characterized in that The measured value is determined by the determination device.

3. The method according to claim 1 or 2, characterized in that: A time period (ts) between the start of the applying and the occurrence of burn-through of the test specimen (50) is determined by a determination device.

4. The method according to any one of the preceding claims, characterized in that The force (F) acting on the test specimen (50) as a result of the applying is continuously determined by a determining device.

5. The method according to claim 4, characterized in that A time period (ts) between the start of the applying and the occurrence of a force drop based on burn-through of the test specimen (50) is determined.

6. The method according to any one of the preceding claims, characterized in that The mass flow (22) flows through an opening (58) in the test specimen (50) produced by the burn-through.

7. The method according to any one of the preceding claims, characterized in that The point in time (t0) at which the application starts is determined by the force increase.

8. The method according to any one of the preceding claims, characterized in that The temperature of the sample (50) is determined.

9. The method according to claim 8, characterized in that The temperature is determined on a side (52) of the sample (50) facing away from the mass flow (22).

10. The method according to claim 8 or 9, characterized in that: The start of the application is determined by the exceeding of a predetermined temperature of the test specimen.

11. The method according to any one of claims 8 to 10, characterized in that The determination of the force and / or the temperature is performed in a common data acquisition device (100).

12. The method according to claim 11, characterized in that The public data collection device (100) comprises a multimeter.

13. The method according to any one of the preceding claims, characterized in that The impulse acting on the test specimen (50) is determined by the force (F) acting during the time period (ts).

14. The method according to any one of the preceding claims, characterized in that Recording a thermal image and / or a thermal diagram of the sample (50).

15. The method according to any one of the preceding claims, characterized in that An acoustic signal is determined during the applying.

16. The method according to any one of the preceding claims, characterized in that The jet velocity of the mass flow (22) is determined.

17. A method according to any one of the preceding claims, characterised in that The test specimen (50) comprises a material for a battery housing, or is a battery housing or a portion of a battery housing.

18. A method according to any one of the preceding claims, characterised in that The mass flow (22) is directed orthogonally or at an angle to the sample (50).

19. The method according to any one of the preceding claims, characterized in that The mass flow (22) is provided by a rocket propellant charge, an acetylene burner with a mass feed, flame spraying or plasma spraying.

20. The method according to any one of the preceding claims, characterized in that The mass flow (22) flows through the nozzle (21), and the discharge characteristic of the mass flow (22) is adjusted thereby.

21. A test device (10) for thermomechanical testing of a specimen (50), comprising a base frame (30) having a receiving portion (32) in which the specimen (50) can be directly or indirectly received, and an application member (20) for providing a high-speed thermal mass flow (22) that can be directed onto the specimen (50).

22. The testing device (10) according to claim 21, characterized in that The testing device (10) has a determination device.

23. The testing device (10) according to claim 22, characterized in that The determination device is designed to determine the burn-through resistance of the test specimen (50), in particular the time-dependent burn-through resistance of the test specimen (50).

24. The testing device (10) according to claim 22 or 23, characterized in that The determining device comprises a force measuring device (40) operatively coupled to the base frame (30) and arranged to determine a force (F) introduced into the specimen (50) by the mass flow (22).

25. The testing device (10) according to any one of claims 21 to 24, characterized in that The determining device comprises a temperature measuring device (81) for determining the temperature of the sample (50).

26. The testing device (10) according to any one of claims 21 to 25, characterized in that The application member (20) is received in a blind hole opening of the support element (90).

27. The testing device (10) according to any one of claims 21 to 26, characterized in that The application member (20) is adjustable relative to the chassis (30).

28. The testing device (10) according to any one of claims 21 to 27, characterized in that The angle and / or distance of the application member (20) relative to the chassis (30) is adjustable.

29. The testing device (10) according to any one of claims 21 to 28, characterized in that A baffle (60) is arranged on a side of the receiving portion (32) facing away from the application member (20).

30. The testing device (10) according to any one of claims 21 to 29, characterized in that A sample holder (38) is provided, in which the sample (50) can be accommodated, wherein the sample holder (38) is accommodated in the receptacle (32).

31. The testing device (10) according to claim 30, characterized in that The sample holder (38) is designed in a frame shape so that the sample (50) can be inserted therein.

32. The test device (10) according to any one of claims 21 to 31, characterized in that A fixing device (37, 39) is provided for fixing the sample (50) or the sample holder (38) to the receiving portion (32).

33. The testing device (10) according to any one of claims 21 to 32, characterized in that The determination device comprises a high-speed camera (82, 83) and / or an infrared camera (84) and / or an acoustic measurement device (85).

34. The testing device (10) according to any one of claims 21 to 33, characterized in that The test device has an air suction device and / or an exhaust fan device (67), or the test device can be connected to the air suction device and / or the exhaust fan device.

35. The testing device (10) according to any one of claims 21 to 34, characterized in that The force measuring device (40) is at least partially surrounded by a shield or enclosure (42).

36. The testing device (10) according to any one of claims 21 to 35, characterized in that A jet velocity measuring device is provided, which is used to determine the jet velocity of the mass flow (22).

37. The testing device (10) according to any one of claims 21 to 36, characterized in that The application member (20) is designed as a rocket propellant charge, an acetylene burner with mass feed, a flame spray device, a galvanic cell or a plasma spray device.

38. The testing device (10) according to claim 37, characterized in that The rocket propellant charge is a solid composite propellant charge.

39. The testing device (10) according to claim 37 or 38, characterized in that The rocket propellant charge can be activated by electrical ignition.

40. The testing device (10) according to any one of claims 21 to 39, characterized in that A shielding member (24) and / or a deflecting device (25) is arranged between the application member (20) and the receiving portion (32).

41. The testing device (10) according to any one of claims 21 to 40, characterized in that The application member comprises a nozzle (21) or is connectable to said nozzle.

42. The testing device according to claim 41, characterized in that The nozzle (21) has a nozzle outlet channel (211) having a predetermined length (212), a predetermined opening cross section (213) and a predetermined opening angle (α).

43. A testing device (10) for carrying out the method for testing a test specimen (50) according to any one of claims 1 to 20, characterized in that: The testing device (10) is designed according to any one of claims 21 to 42.

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