Method and testing device for thermomechanical testing of a specimen

Abstract

The invention relates to a method for thermomechanical testing of a test specimen (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 test specimen (50), comprising a chassis (30) with a receiving portion (32) and an application member (20) for providing a high-speed mass flow (22).

Description

Technical Field

[0001] The object of this invention is a method for thermomechanical testing of a sample according to the preamble of claim 1. Furthermore, the object of this invention is a testing apparatus for thermomechanical testing of a sample according to the preamble of claim 9. Background Technology

[0002] Fireproof shielding must have sufficiently high burn-through resistance, especially time-related burn-through resistance. Furthermore, the heat of the fire must be shielded. One example is the shielding of the battery of an electric motor vehicle relative to the passenger compartment. The design must ensure that flames from the battery do not directly penetrate the passenger compartment, but allow passengers to safely stop and exit the vehicle or be rescued within a time period specified by the test rules. Other applications of this shielding include fire-resistant shielding devices in buildings, ships, or aircraft. Therefore, it is necessary to select or develop materials with appropriate properties and sufficiently high burn-through resistance over time for such shielding. For this purpose, it is necessary to test the intended materials (“actual properties”) based on the energy and material flow of the action. In the context of this invention, such testing is referred to as “thermomechanical testing”.

[0003] As is known from the prior art, the intended material is tested in a practical apparatus using actual methods. The degree of damage to the fireproof shield is determined by observing the specimen. A drawback of this known solution in the prior art is that it only allows for a very imprecise determination of fire resistance and its dependence on operational properties. This is due to the variability in energy and material flow. Furthermore, repeatability is extremely poor, making it impossible to achieve an objective testing process for the specimen using such an apparatus.

[0004] DE 24 35 999 A1 discloses a method and apparatus for testing thermoplastics, wherein a sample is subjected to a jet of hot gas.

[0005] US 3,908,440 A discloses an apparatus and method for applying a high-speed thermal mass flow to a specimen, wherein the specimen is clamped on one side and has a free end. Mass flows are applied to both sides of the specimen, with mass blocks disposed at the free end of the specimen. A measuring scale is used to determine the specimen deformation (deflection) caused by the thermal load.

[0006] In addition, US 7,966,868 B1 discloses an apparatus and a method for applying a high-speed hot mass flow to a sample to test a gas turbine and its components.

[0007] CN 111 562 189 A describes a testing device having an adjustable application member for providing a high velocity mass flow, wherein the application member is directed to a test specimen fixed on a chassis. The jet flow of the application member flows through a Laval nozzle.

[0008] DE 14 46 965 C discloses a device and a method for simulating explosion pressure and temperature.

[0009] Furthermore, DE 10 2020 118 072 A1 discloses a testing device for testing the resistance of a test specimen to particle impact and high temperatures. The test specimen is a battery for an electrically driven vehicle.

[0010] CN 111 024 750 A describes a device and a method for ablative testing of ceramic matrix composites using a controllable gas environment. SUMMARY

[0011] It is therefore an object of the present invention to provide a method for the thermomechanical testing of a test specimen which ensures an improved repeatability. Furthermore, it is another object to provide a testing device for the thermomechanical testing of a test specimen which provides repeatability and has a compact structure.

[0012] The method according to the present invention is a method for the thermomechanical testing of a test specimen, wherein a high velocity thermal mass flow is applied to the test specimen, wherein a force resulting from the application by the action on the test specimen is continuously determined by a determination device.

[0013] Due to the method according to the present invention, an accurate fire protection testing of a test specimen can be achieved without the expense of an actual device. Thereby, a test specimen can be tested faster and more economically before its material is used for a fire protection shield, or a proper preselection from a large number of materials can be made before further testing is performed. The damage pattern of a test specimen, in particular of the side facing the mass flow, can be evaluated in terms of a relative damage intensity, and different test specimens can be objectively compared to each other. A further advantage of the method according to the present invention is an increased repeatability compared to the prior art, such that upon performing the method again with a similar test specimen, technically identical results are obtained, thereby creating an objective testing method which provides the possibility to compare different test specimens in an objective and standard manner.

[0014] After performing the method according to the present invention, the test specimen is damaged, although it does not necessarily have to be burned through, i.e. it is intact. However, it is also possible that the test specimen is burned through.

[0015] In an advantageous refinement of the method, the at least one measurement value can be determined by a determination device. The measurement value is not limited to the determination of a physical quantity, such as a force or a temperature, an acoustic measurement variable; for example, this can also refer to the determination of an image. The term "measurement value" is therefore to be interpreted broadly. Preferably, the measurement 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 application can be further increased.

[0016] In an advantageous refinement of the method, the time period between the start of the application and the occurrence of the burn-through of the test specimen can be determined by means of the determination device.

[0017] By means of this refinement, the time period until the burn-through of the test specimen can be determined precisely, which can be regarded as a measure of the fire shielding performance.

[0018] According to the application, the force acting on the test specimen as a result of the application is determined continuously by means of the determination device. The determined force or force curve can provide information about the mass flow acting, so that this information can be used for the normalization between two or more runs of the method according to the application and thus increase the reproducibility. In other words, fluctuations in the acting properties can be determined and can be taken into account accordingly in the evaluation.

[0019] Preferably, the time period between the start of the application and the occurrence of the force drop based on the burn-through of the test specimen can be determined.

[0020] A particularly preferred method is a method for determining the time-dependent burn-through 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 as a result of the application is determined continuously, wherein the time period between the start of the application and the occurrence of the force drop based on the burn-through of the test specimen is determined.

[0021] The force is determined by means of a determination device. For this purpose, the force introduced into the test specimen by the high-speed thermal mass flow is determined continuously over the entire application time, so that the time period between the start of the application and the occurrence of the force drop based on or due to the burn-through of the test 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 point in time of the start of the application and the point in time of the occurrence of the force drop based on the burn-through of the test specimen can be determined. The determination device can comprise the time measuring device.

[0022] In other words, during the entire time of the application of the high-speed thermal mass flow (in the following also referred to as mass flow) to the test specimen, the force introduced into the test specimen by the mass flow is determined by the determination device designed as force measuring device and can preferably be plotted in a force-time curve (also referred to as force-time run). As soon as the test specimen burns through, the force drops, i.e. the force introduced into the test specimen by the mass flow suddenly decreases, since the mass flow no longer introduces any force into the test specimen or at least only a small amount of force, since the mass flow flows through or penetrates the test specimen due to the burning through of the test specimen. The point in time of the force drop corresponds to the point in time of the burning through of the test specimen, so that the time period between the start of the application and the occurrence of the burning through of the test specimen can be determined very precisely. The point in time of the start of the force drop preferably corresponds to the point in time of the start of the burning through of the test specimen. By means of the method according to the application, this time period can be determined with an accuracy of up to 1 / 10 (0.1) seconds.

[0023] The time-relevant burn-through resistance of the test specimen corresponds to the time period between the start of the application and the start of the burning through of the test specimen, i.e. the breakthrough of the high-speed thermal mass flow through or past the test specimen. The time-relevant burn-through resistance can thus be regarded as a kind of component or material property which can give information about the fire protection properties and the heat effect resistance of the component or material. Preferably, the method according to the application is suitable for determining a pulse run (pulse curve), in particular by continuously determining the force.

[0024] The high-speed thermal mass flow (or simply mass flow) is provided by the application means and introduces heat and force into the test specimen. The high-speed thermal mass flow can be in the form of a jet directed at the test specimen. The force introduced into the test specimen by the mass flow, i.e. acting on the test specimen, is provided by the impact of the 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 50 m / s, particularly preferably higher than 100 m / s, very particularly preferably higher than 200 m / s. Preferably, the flow velocity is supersonic and higher than 300 m / s. This flow velocity is closest to the thermal runaway condition of the energy accumulator. The temperature of the mass flow is significantly higher than the ambient temperature, so that heat is at least locally transferred to the test specimen and increases its temperature. Preferably, the maximum temperature of the mass flow is preferably higher than the melting temperature of the test specimen. The maximum temperature of the mass flow is preferably higher than 500°C, particularly preferably higher than 600°C, very particularly preferably higher than 800°C. Thereby, the time-relevant burn-through resistance can also be determined for test specimens made of materials having a relatively high melting point. Preferably, the maximum temperature that can be generated for the test specimen is higher than the melting temperature of the test specimen, 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 that the kinetic energy of the mass flow is converted into thermal energy when the mass flow impacts the test specimen, i.e. the temperature of the test specimen increases. Thereby, the test specimen can be heated to a temperature higher than the temperature of the mass flow itself. This makes it possible to save energy and costs.

[0025] The burn-through of the test specimen can also be referred to as a breakthrough of the test specimen, which means a breakthrough of the test specimen against the obstacle constituted by the mass flow. The burn-through of the test specimen indicates that the material of the test specimen is at least partially melted and / or burned by the mass flow, so that the geometry of the test specimen is thereby changed. In other words, the material is at least partially melted and flows out of the area of influence of the mass flow and / or at least partially burned.

[0026] In a preferred refinement, the force introduced is determined continuously with a time resolution of at least 1 / 25 seconds. Thereby, 25 force measurements are recorded per second. In a particularly advantageous refinement, the time resolution is at least 1 / 50 seconds. With this time resolution, the accuracy of the method according to the application can be further improved.

[0027] The test specimen can preferably be designed as a test sheet, for example in the form of a plate, or as a component having a geometry different from a plate. The method according to the application thus offers the possibility of simultaneously testing the burn-through resistance over time of plate-shaped test specimens and real components such as housings or covers.

[0028] Preferably, the force drop occurring as a result of the burn-through of the test specimen can be greater than 50%, particularly preferably greater than 80%, of the force introduced immediately 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. Thereby, the force drops sharply during the burn-through compared to the previously approximately constant force, so that the point in time at which the burn-through of the test specimen and the time period begin can be determined precisely. The force drop preferably occurs within a time of less than 2 seconds, particularly preferably within a time of less than 1.5 seconds and most preferably within a time of less than 1 second. The force drop thus represents a jump in the force-time diagram, so that the point in time at which the force drop begins and thus the point in time at which the burn-through begins can be determined precisely.

[0029] In an advantageous refinement of the method, the mass flow flows through the opening in the test specimen that is produced by the burn-through. The mass flow thus does not flow to the edge portion of the test specimen, but preferably to the central portion of the test specimen, so that an opening having a preferably substantially rounded, in particular substantially circular, shape is formed in the test specimen as a result of the burn-through; the mass flow flows through this test specimen after the burn-through has occurred. Since the mass flow flows through the opening and thus at least no longer impinges on the test specimen completely, it no longer introduces any force or only a very small force into the test specimen compared to the point in time before the burn-through. In other words, the mass flow successfully achieves the burn-through of the test specimen and thereby produces an opening, so that it can flow unhindered through the opening, i.e. no significant force is introduced into the test specimen. Thereby, the force drop caused by the burn-through can be more drastic and the measurement accuracy can be further improved.

[0030] In an advantageous refinement of the method, the point in time of the start of the application is determined by the force increase. At the point in time at which the mass flow is applied to the test specimen, a force is also introduced, so that a test specimen which was not previously loaded is now loaded with the mass flow, i.e. a force is introduced to it. Thereby, the point in time of the start of the application of the force increase can be determined. It is also conceivable and possible that the point in time of the start of the application is different from the point in time of the start of the force increase, but is a later point in time, for example a point in time which has a predetermined time interval from the point in time of the start of the force increase, or that the point in time of the start of the application is the point in time at which the force reaches a first maximum value, for example caused by a starting pulse of the mass flow, a first turning point in the force-time curve. In this way, for example, a preheating phase of the test specimen can be taken into account and the determination of the burn-through resistance with regard to the time can be further improved.

[0031] However, in an alternative embodiment of the method, it is also conceivable and possible that the point in time of the start of the application, for example the ignition point in time, is determined by the start of the high-speed thermal mass flow. With this embodiment of the method, for example, the ignition of a fire occurring in the field 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. Thus, the method according to the application not only provides a possibility for determining the burn-through resistance with regard to the time. Rather, the method according to the application 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 and the final time period in a single run, thus providing a comprehensive result of the burn-through resistance with regard to the time of the test specimen. Thus, the method according to the application not only provides very precise measurement results, but also saves costs and resources.

[0032] In a further advantageous refinement of the method, the temperature of the test specimen is determined. The temperature is determined using a temperature measuring device at the same time as the mass flow is applied to the test specimen. The determination device preferably comprises the temperature measuring device. The temperature measuring device can be designed, for example, as a thermocouple, a thermometer or an infrared thermometer, etc. The temperature measuring device can preferably be designed as an analog or digital measuring device. Preferably, the temperature is determined continuously over time in order to record a temperature-time curve, which can be used to determine the burn-through resistance with regard to the time. The force-time curve can be recorded redundantly, analogously. Preferably, the temperature is measured in the part of the test specimen which is flowed towards by the mass flow. It is particularly preferred that the temperature is determined on the side of the test specimen which faces away from the mass flow. Thereby, the temperature of the part of the test specimen which is applied with the mass flow but not directly hit by the mass flow can be determined. In other words, the test specimen screens the temperature measuring device. The side of the test specimen which faces away from the mass flow is the side of the test specimen which faces away from the side which is hit by the mass flow before the burn-through. In other words, the facing away side is the back side of the side which is hit by the mass flow before the burn-through. In practical applications, the side of the test specimen which faces away from the mass flow is the side of the test specimen which is protected from the fire. Furthermore, this can also lead to conclusions about the thermal conductivity of the test specimen.

[0033] In a further advantageous refinement of the method, the temperature can be determined at a plurality of points on the test specimen. Thereby, the temperature distribution and the temperature propagation, i.e. their change over time, can be determined.

[0034] In a further advantageous refinement of the method, the start of the application can be determined by the overshooting of a predetermined temperature of the test 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 test specimen is exceeded. Thereby, the preheating phase of the test specimen can be ignored when determining the burn-through resistance in relation to time, i.e. the preheating phase is excluded from the time period used as a measure for the burn-through resistance in relation to time.

[0035] In a further advantageous refinement 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 offers 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 for the burn-through resistance in relation to time. The common data acquisition device can preferably comprise a multimeter. The determination device preferably comprises the data acquisition device.

[0036] Furthermore, in an advantageous refinement of the method, the impulse acting on the test specimen can be determined by the force acting within the time period. In this way, the force determined continuously over the application time can be used to determine the impulse or the impulse curve introduced into the test specimen by the mass flow. The impulse essentially corresponds to the so-called Schubintegral of the mass flow. The Schubintegral can be used as a measure for the damage. Preferably, the impulse can be between 1 Newton second (Ns) and 250 Ns. It has proven particularly advantageous to introduce a mass flow into the test specimen which introduces an impulse of up to 1000 Ns. This saves costs and resources.

[0037] In an advantageous refinement, a Thermofotografie and / or a Thermografie of the test specimen can be recorded. This can be done, for example, using an infrared camera, whereby the determination device can comprise an infrared camera. Thereby, the temperature distribution of the test specimen can be determined over the application time, which also makes it possible to determine so-called hotspots in the test specimen. The Thermofotografie and / or the Thermografie is preferably carried out on the side of the test specimen facing away from the mass flow. The advantage of this is that the interference caused by the mass flow is reduced and the shielded side of the test specimen is observed. In an advantageous refinement, the Thermografie can be carried out as a differential Thermografie, thereby reducing the Albedo. Thus, the burn-through resistance in relation to time can be determined by the determination device comprising an infrared camera.

[0038] In a further advantageous refinement, the applied video recording can preferably be obtained at an image frequency of more than 30 images per second (frames per second; fps), particularly preferably more than 100 images per second and very particularly preferably more than 200 frames per second. The video recording can be carried out, for example, using a high-speed camera, wherein the determination device can comprise the high-speed camera. The video recording preferably records the impingement of the mass flow on the test specimen and / or on the side of the test specimen facing away from the mass flow. Thus, the burn-through resistance in relation to time can be determined by means of the determination device comprising the high-speed camera.

[0039] In an advantageous refinement, in addition to the force and the temperature, the data acquisition device, which is designed, for example, as a computer, can also record thermal images and / or thermographs and / or video recordings of the camera.

[0040] Preferably, the data acquisition device is designed in such a way that it automatically synchronizes the curves of the measured values, for example of the force or the temperature, of the individual measuring devices with the video recordings and / or thermal images and / or thermographs using markers. Preferably, the results obtained are stored by the data acquisition device in a common file. For example, a firing pulse, an optical or acoustic firing signal or the like can be used as a synchronization marker.

[0041] In an advantageous refinement, the data acquisition device can be designed to evaluate the video of the spark on the side of the test specimen facing away from the mass flow by means of automatic image evaluation, in order to determine the point in time at which the spark begins to fly. The beginning of the spark to fly on the side of the test specimen facing away from the mass flow corresponds to the burn-through of the test specimen. This can be carried out in addition to the force measurement or the temperature measurement, but also without the force measurement or the temperature measurement.

[0042] In a further advantageous refinement, the data acquisition device can be designed in such a way that the video is scanned by means of automatic image evaluation in order to obtain the point in time at which the mass flow is applied to the test specimen. In other words, the relevant points in time for determining the time period, i.e. the point in time of the beginning of the application and the point in time of the occurrence of the burn-through, and thus the burn-through resistance can be determined by means of automatic image evaluation of the video recording. In this way, a redundancy to other measuring devices can be achieved and the accuracy can be further improved. Alternatively, the automatic image evaluation can also be carried out without the use of additional measuring devices.

[0043] In an advantageous refinement of the method, an acoustic signal can be determined during the application. This acoustic signal can be determined using an acoustic measuring device, which can comprise, for example, a microphone. Preferably, the determination device comprises the acoustic measuring device.

[0044] The acoustic measuring device is preferably connected to the data acquisition device. Thereby, all measurement data obtained can be processed and synchronized in the common data acquisition device.

[0045] In an advantageous refinement, the sound signal can also be started before the application. Thereby, the point in time at which the application of the mass flow to the test specimen is started can be determined acoustically, so that a redundancy can be created here and this can be used as a synchronization marker for the individual measurement sequences. Alternatively, an acoustic evaluation can also be carried out without the use of additional measurement devices.

[0046] Furthermore, the sound signal can also be used to determine the point in time at which the test specimen is burnt through. Thereby, the time period can be determined by the acoustic measurement device as a measure of the burn-through resistance in relation to the time.

[0047] Furthermore, the acoustic measurement device can also provide a redundancy for other measurement devices based on different measurement principles. Furthermore, by determining the acoustic signal, the following advantage is provided: its measurement properties are not impaired during the application by the production of smoke, which can occur, for example, in the case of the use of optical measurement devices, such as cameras. Thereby, it can be ensured that the burn-through resistance can be determined even if the other measurement devices are impaired, and due to the determination of the acoustic signal, an expensive repeat test is not necessary.

[0048] In a further 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 measurement device, for example, this can be done using the Doppler spectroscopy method. Preferably, the jet velocity can be determined spatially before the application of the mass flow to the test specimen. In other words, the jet velocity measurement device is arranged spatially between the application member and the test specimen. The advantage of this is that, for example, in addition to the force or temperature introduced into the test specimen, the jet velocity can also be determined continuously, and a diagram can be plotted over time, so that any changes in the force curve / temperature curve can be compared with changes in the jet velocity curve, whereby the measurement accuracy of the inventive method can be further improved. The mass flow can be calculated by force and velocity measurement. Alternatively or additionally, the jet velocity of the mass flow can be determined on the side of the test specimen facing away from the mass flow, i.e. here only the jet velocity of the mass flow is determined after the burn-through. The jet velocity of the mass flow can also be referred to as the flow speed of the mass flow.

[0049] In an advantageous refinement, the test specimen comprises a material for a battery housing or is a battery housing or a partial battery housing. The method according to the invention is particularly suitable for determining a material, i.e. a material for a battery housing or a partial battery housing, or a battery housing itself. The battery housing serves to accommodate and shield a battery. A battery is also understood to be an accumulator, in particular a lithium-ion accumulator for electrically driven vehicles. 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.

[0050] In an advantageous refinement, the mass flow flows orthogonally or at an angle to the test specimen. This increases the variability of the method, so that the mass flow can be applied to the test specimen 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 means for providing the mass flow and the test specimen in order to adjust the temperature profile and the jet characteristics.

[0051] In a preferred embodiment of the method, the mass flow is provided by a rocket propellant charge, an acetylene burner with mass feed, a flame spray, a galvanic element or a plasma spray. 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.

[0052] In an advantageous refinement, the galvanic element is designed as a secondary cell, also referred to as a battery. The galvanic element comprises at least one cell. The galvanic element is particularly preferably designed as a lithium-ion cell. Due to this design of the application means, the test specimen can be tested under quasi-real conditions.

[0053] In an advantageous refinement, the galvanic element is preferably arranged such that the mass flow flows out of the galvanic element against the force of gravity. This provides the advantage that, in comparison with a hanging arrangement, no or only a small amount of flammable liquid electrolyte escapes from the galvanic element before the mass flow flows out, thus preventing uncontrolled combustion or even deflagration.

[0054] In a further advantageous refinement, the fuel of the application means for providing the mass flow can be weighed at least before the start of the application and after the application; preferably, the weighing is carried out continuously during the application. Thereby, the mass of the fuel is determined before or after the application or during the application, so that it can be compared with the fuel consumption of other experiments, so that any faulty application means can be determined. The weighing can be carried out using a mass measuring device, for example in the form of a scale.

[0055] In an advantageous refinement, a mass flow can flow through the nozzle and the discharge characteristics of the mass flow are thereby adjusted. In this case, the mass flow flows from the application member through the nozzle and impinges on the test specimen after passing through the nozzle, wherein the nozzle is preferably spaced apart from the test specimen. The nozzle has a predetermined nozzle geometry which is designed in such a way 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 the thermal runaway, in particular with regard to temperature, jet 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 real situation, for example a failure of a lithium-ion battery. In particular, the following geometric features of the nozzle can be varied: central nozzle hole, opening angle of the cone, length of the central nozzle hole and length of the cone.

[0056] The nozzle is preferably used in combination with a rocket propellant charge.

[0057] Furthermore, a test device for the thermomechanical testing of a test specimen is proposed, comprising a chassis having a receiving portion and an application member for providing a high-speed thermal mass flow, which can be directed to the test specimen, wherein the test device has a determination device, which comprises a force measuring device, which is operatively connected to the chassis and is arranged to determine the force introduced into the test specimen by the mass flow.

[0058] By means of the test device according to the application, the fireproofing properties of preselected materials can be tested without a great deal of effort and expense.

[0059] The test device is preferably suitable for carrying out the previously described method with all the aforementioned refinements. Thus, all the aforementioned features of the method and advantageous refinements thereof can be transferred to the test device accordingly. Likewise, all the features of the test device and refinements thereof explained below can be transferred to the method and advantageous refinements thereof.

[0060] The test device has a determination device. Due to the determination device, measurement values 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 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 individually or in combination.

[0061] Furthermore, due to the reproducible conditions (and the measurement thereof), even if the test specimen is not burned through, the relative burn-through resistance of the test specimens can be compared in terms of surface damage and / or backside temperature, so that an effective preselection (preselection of variants of the test specimen) is carried out in order to subject the "best" test specimen to further, more complex fireproofing tests.

[0062] Preferably, the determination device is designed to determine the burn-through resistance of the test specimen, in particular the time-related burn-through resistance of the test specimen.

[0063] In this way, the time period until the burn-through of the test sample can be determined precisely.

[0064] According to the application, the determination device can comprise a force measuring device, which is effectively coupled to the base frame and is designed to determine the force introduced into the test sample by the high-speed thermal mass flow.

[0065] The test device can thus be used to continuously determine the force introduced into the test sample by the high-speed thermal mass flow over the entire application time. Fluctuations in the mass flow can thus be determined easily in order to take them into account accordingly when evaluating the test. The test accuracy can thus be further improved.

[0066] Furthermore, the time period between the start of the application and the occurrence of a force drop based on or due to the burn-through of the test sample can be determined. To this end, the force measuring device is preferably designed such that it detects the force continuously over the application time.

[0067] The base frame of the test device has a receptacle in which the test sample can be accommodated directly or indirectly, i.e. via an intermediate element. The receptacle is preferably designed as a recess or opening in which the test sample or the intermediate element can be accommodated such that the test sample is preferably held fixedly in an exact position relative to the receptacle at least in the direction of action of the mass flow.

[0068] The base frame can be effectively coupled to a force measuring device, wherein the force measuring device is designed to determine the force introduced into the test 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 test sample accommodatable in the receptacle and the force measuring device. The force introduced into the test sample by the mass flow can thus be determined by the force measuring device.

[0069] The application member is designed to provide a high-speed thermal mass flow, which is oriented such that the mass flow will hit the test sample accommodatable in the receptacle. In other words, the application member is aimed at the position predetermined for the test sample by the receptacle.

[0070] In an advantageous refinement, the base frame comprises a temperature- and fire-resistant material, for example a material made of steel and / or a ceramic material. In this way, it can be ensured that the base frame is not damaged by the mass flow when applying the mass flow to the test sample, thereby increasing the service life of the test device.

[0071] In an advantageous refinement, the force measuring device can comprise a force transducer. Force transducers are also referred to as force sensors or load cells. In particular, the force transducer can be designed as a piezoelectric transducer. The force measuring device is preferably arranged between the base frame and a rigid support structure, for example a machine tool, a base or a stand. In a preferred refinement, the force measuring device has a nominal force of between 250 N and 750 N, particularly preferably 500 N.

[0072] In a preferred refinement, the force measuring device can be calibrated only for compressive or tensile forces, since the mass flow introduces forces with previously known direction into the test specimen and thus compressive or tensile forces act. Thereby, the accuracy can be increased and the calibration process can be simplified. Standard weights of 1 kg or 5 kg are particularly suitable for calibration.

[0073] In an alternative embodiment, the force measuring device can be used to measure the displacement (stroke) of the chassis relative to the rigid seat, wherein an elastic element is arranged between the chassis and the seat. The elastic element can comprise at least one spring element, for example in the form of a helical spring or a coil spring. Since the stiffness of the elastic element is known, the force acting on the chassis can be calculated on the basis of the displacement of the chassis relative to the rigid seat. In an advantageous refinement, 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 increased. Furthermore, an additional damping element can be arranged between the chassis and the rigid seat. In this way, vibrations in the system can be suppressed and the measurement of the force is further improved.

[0074] In an advantageous refinement, the determination device can have a temperature measuring device for determining the temperature of the test specimen. 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 can preferably be designed as an analog or digital measuring device. It is preferably arranged on the side of the receiving portion or the test specimen facing away from the application member or aligned with the application member, i.e. it determines the temperature of the back side of the test specimen or, when using a plurality of thermocouples and / or a plurality of thermometers and / or a plurality of infrared thermometers, the temperature of the back side of the test specimen and its distribution. The side facing away from the application member corresponds to the side facing away from the mass flow of the test specimen.

[0075] In a further advantageous refinement, the application member is accommodated in a blind hole opening of a support element. The support element can be designed as a tube closed on one side and has a cup-shaped recess in which the application member is accommodated and advantageously held in an exact 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 out of the support element. The locking device can be designed as a force-fitting locking device, for example a clamping device, and / or as a form-fitting locking device, for example one or more locking elements. The support element can be connected to the seat 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.

[0076] 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 test specimen, so that the mass flow can be applied to the test specimen in a desired manner. Preferably, the support element is held on the seat frame in an adjustable manner.

[0077] Preferably, the angle and / or the distance of the application member relative to the base frame can be adjustable. Thus, the application member can be adjusted so that the mass flow hits the test specimen orthogonally or at an angle. Furthermore, the distance between the application member and the base frame and thus also relative to the test specimen that can be accommodated in the receptacle can be adjusted. Preferably, the support element is held pivotably on the seat frame. Alternatively or additionally, the support element can be held on the seat frame in a displaceable manner, so that the distance of the support element from the base frame can be adjusted and / or the support element can be adjusted parallel to the receptacle or the test specimen, so that, at a set angle of the application member, the application member is aligned with the receptacle or the test specimen, i.e. so that the mass flow hits, preferably, the center of the test specimen. 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 test specimen.

[0078] The test device preferably has a baffle that is arranged on the side of the receptacle facing away from the application member. The baffle is preferably made of or comprises a temperature- and fire-resistant material, for example steel or a ceramic material. The baffle should not be understood to mean that it has to be made of a metal plate. Alternatively, the baffle can also be referred to as a baffle element. The baffle is arranged in the path of the mass flow in order to guide the mass flow in a predetermined direction by the baffle after the test specimen has burned through. This allows the mass flow to flow in a direction towards the suction device. Preferably, the baffle is rotatably and / or displaceably adjustable relative to the base frame. 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 towards the suction device. The baffle is preferably arranged to be force-decoupled from the force measurement device. This can ensure that the force measurement device only determines the force introduced into the test specimen and that the measurement is not distorted by the mass flow hitting the baffle after the burn-through.

[0079] In an advantageous refinement, a test specimen holder is provided, in which the test specimen can be accommodated, the test specimen holder being accommodated in the receptacle. By means of the test specimen holder, the test specimen can be placed on the test device easily, conveniently and time-savingly. The test specimen holder preferably has a grid grate that can be placed over the test specimen. This ensures that the test specimen is arranged firmly on the test specimen holder. The test specimen holder is preferably made of or comprises steel or aluminum.

[0080] The 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 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 a metal oxide ceramic material such as aluminum oxide or mullite. However, other ceramic materials for the fibers and / or the matrix are also possible. A large number of materials that are essentially suitable for both the matrix and the fibers are known in the prior art.

[0081] It has turned out that such a grid can withstand high thermal loads, so it is particularly suitable for specimens containing organic insulating materials, as these materials often lead to fires and deflagrations.

[0082] The grid preferably has a central opening with an area of between 3 cm 2 and 25 cm 2 , so that the mass flow can act unhindered on the specimen. It is particularly preferred that in the case of a low scattering mass flow (opening solid angle of the mass flow less than 10°), the central opening has an area of between 3 cm 2 and 7 cm 2 , in particular an area of 5 cm 2 . It is particularly preferred that in the case of a scattering mass flow (opening solid angle of the mass flow greater than 10°), the central opening has an area of between 10 cm 2 and 20 cm 2 .

[0083] It has been shown that a scattering mass flow largely corresponds to the mass flow of a damaged battery. In particular, a distance between the application means 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°, in which the distance of the application means from the specimen is 50 mm and the central opening area of the grid is 16 cm 2 .

[0084] The opening solid angle is the opening angle of the mass flow cone, which is twice the angle between the surface generatrix (Mantellinien) and the cone axis.

[0085] Preferably, the opening solid angle has a value between 3° and 10°. The grid is preferably fixed at a distance from the sample surface. This can be done, for example, by fixing the grid on the sample holder or in a floating manner on the sample. By "floating support" is meant that the grid is placed on the sample or at a distance from the sample. The grid is subjected to a vertically downward force, for example the weight of the grid and components connected to the grid. The floating grid can also have vertical guide rails to allow the grid to move in the vertical direction, but to fix it in the XY plane. Preferably, the distance between the grid and the sample surface is preferably between 1 and 5 mm.

[0086] In an advantageous embodiment, the sample holder is designed in a frame-like manner, so that the sample can be inserted therein. With this design, it can be ensured that the sample holder is not damaged and / or this has no or only a very small influence on the measurement result when the mass flow is applied to the sample.

[0087] In an advantageous embodiment of the test device, there can be a securing device provided for securing the sample or the sample holder on the accommodation. The securing device can be switched between a securing position and a release position, so that in the securing position the sample or the sample holder is secured relative to the accommodation and in the release position the sample or the sample holder can be accommodated in or removed from the accommodation. The securing device can be designed as a clamping device, for example a clamping lever or a tensioning lever. Alternatively or additionally, the securing device can be designed as a form-fit locking device. Furthermore, the securing device can also be formed by a screw element such as a screw, a nut or a stud bolt. The securing device ensures that the sample or the sample holder does not move during the application of the mass flow. In an advantageous refinement, such a securing device can also be additionally provided on the sample holder in order to secure the sample relative to the sample holder.

[0088] In an advantageous further development, the determination device can comprise a high-speed camera and / or an infrared camera and / or an acoustic measuring device. The infrared camera can be used to record thermal images and / or thermographs of the test specimen. The infrared camera is directed at the test specimen accommodated in the accommodation or insertable into the accommodation. Preferably, the infrared camera is directed at the side of the accommodation opposite the application member or the test specimen insertable into the accommodation. This allows thermal images or thermographs of the back side of the test specimen to be recorded. A high-speed camera, also referred to as a high-speed camera, can be used to record a video of the application of the mass flow on the test specimen. For this purpose, the high-speed camera is directed at the test specimen accommodatable in the accommodation, preferably such that a video of the impact of the mass flow on the test specimen and / or on the side of the test specimen facing away from the mass flow can be recorded. Preferably, the high-speed camera is set up such 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 can comprise a filter device, the effect of which is, for example, similar to welding goggles. The video recording of the application is thereby improved. It is also possible to provide two high-speed cameras, one of which comprises a filter device and is preferably directed at the impact of the mass flow on the test specimen. The acoustic measuring device is preferably designed as a microphone. This microphone is particularly preferably designed as a directional microphone and is directed at the application member or the test specimen. The test device can have two microphones, one of which is directed at the application member and the other of which is directed at the test specimen. The advantage of the acoustic measuring device is that its measuring properties are not impaired by the production of smoke during the application.

[0089] In an advantageous further development, the infrared camera and / or the high-speed camera and / or the acoustic measuring device can be adjustably mounted on a holder. The infrared camera and / or the high-speed camera can thus be optimally directed at the impact of the mass flow.

[0090] In a further advantageous further development, the test device has or can be connected to a suction device and / or an exhaust fan device.

[0091] The suction device can be used to extract the gases and smoke produced by the mass flow. For example, the suction device can be arranged at the accommodation or at the side of the test specimen facing away from the mass flow, such that the mass flow can be at least partially extracted after the burn-through. Alternatively or additionally, the suction device can also be arranged at the side of the accommodation facing the mass flow, such that the smoke produced during the application can be extracted by means of this suction device. The advantage of this is that the field of view of the test specimen remains clear during the application when using the high-speed camera and is not influenced by the smoke. By using the high-speed camera, the accuracy of the test can thus be further improved, for example when determining the burn-through resistance with respect to time.

[0092] The suction device can be part of the test device or can be connected to the test device, for example, by means of a hose. The suction device preferably comprises a wet scrubber and / or a HEPA filter (HEPA: High-Efficiency Particulate Air / Arrestance Filter). Such a wet scrubber serves to wash off components that are harmful to health and the environment, such as acids and fumes. The HEPA filter can clear soot, fine particles and dust.

[0093] The exhaust fan device can be provided as an alternative or in addition to the suction device, which is preferably arranged on the side of the receiving portion facing the mass flow. The exhaust fan device is arranged and designed in such a way that it removes the fumes generated during the application by means of a fluid flow, in particular an air flow. The advantage of this is that the field of view of the test specimen remains clear during the application when using a high-speed camera and is not affected by fumes. The accuracy when determining the time-related burn-through resistance using a high-speed camera can thus be further improved. The size of the fluid flow must be set in such a way that its influence on the mass flow during the application is negligible and technically negligible.

[0094] The exhaust fan device can preferably comprise a compressed air lance for guiding the fluid flow, which can be connected to a compressed air hose for connecting the compressed air lance to a pneumatic system. Alternatively or additionally, the exhaust fan device can comprise a fan and / or a compressor.

[0095] In a further advantageous embodiment of the test device according to the application, the force measuring device is at least partially surrounded by a shield or a package. It is particularly preferred that the force measuring device is completely surrounded by a package, wherein the electrical lines pass through the package in a sealed manner. Preferably, the shield or the package is a sealed thermal package. In this way, at least the negative interfering influence of the gases and particles emitted by the mass flow on the force measuring device is greatly reduced, thereby counteracting a distortion of the force measurement, thereby further improving the measurement accuracy of the test device.

[0096] In an advantageous embodiment, a jet velocity measuring device can be provided for determining the jet velocity of the mass flow. The jet velocity measuring device can 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 can be arranged between the receiving portion and the application member, so that the jet velocity can be determined spatially before the mass flow hits the test specimen. Alternatively or additionally, this or another jet velocity measuring device can be arranged on the side of the receiving portion or the test specimen facing away from the application member. Thereby, the jet velocity can be determined after the test specimen has burned through.

[0097] In an advantageous refinement, the application member is designed to provide a pulse of between 1 Newton second (Ns) and 250 Ns, particularly preferably of between 1 Ns and 100 Ns.

[0098] In a further advantageous refinement, the application member is designed to provide the mass flow over a flow duration of between 2 seconds and 30 seconds, particularly preferably over a flow duration of between 5 seconds and 25 seconds. Thereby, it can be ensured that the mass flow is applied to the test specimen over a sufficient time, so that the time-dependent burn-through resistance can be determined, and the mass flow does not continue to flow for a useless time after the burn-through. In other words, the flow duration can be adapted to the properties of the test specimen or to the flow duration of the fire to be simulated, for example the thermal runaway of a lithium-ion battery.

[0099] Preferably, the fuel of the application member is selected such that the mass flow has a specific flow rate, momentum, temperature, opening angle and chemical composition. The fuel supply makes it possible to adjust the fuel and supply it to the application member according to a demand curve. It is thus conceivable and possible to adjust the fuel and the amount thereof before the application or even during the application. The mass flow can thus be adjusted according to the intended test parameters.

[0100] In a preferred embodiment, the application member has a device designed to add particles to the mass flow. The mass flow is preferably a gaseous flow. In this way, for example, the force introduced into the test specimen by the mass flow can be adjusted.

[0101] Preferably, the test device can comprise a mass measuring device for determining the mass of the fuel of the application member. The mass measuring device can be designed, for example, in the form of a balance. Alternatively, the volume of the fuel can also be determined, from which the mass can then be determined.

[0102] In an advantageous refinement, the application member has a nozzle or can be connected to a nozzle. The nozzle preferably has a nozzle outlet channel with a predetermined length, a predetermined opening cross section and a predetermined opening angle. The nozzle thus has a predetermined nozzle geometry at the outlet end. The nozzle geometry can be selected such that different emission characteristics can be set with the same type of application member, for example the impact area and / or the impact velocity of the mass flow 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 outlet cone), the opening cross section (diameter of the outlet opening) and the opening angle (cone opening angle of the outlet). Thereby, the pulse and the impact area can be specifically adjusted.

[0103] The opening angle of the nozzle outlet can be selected depending on the desired discharge characteristics. For example, the opening angle can also be zero, so that the nozzle outlet is formed by a cylindrical passage. 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 axis of the cone.

[0104] Due to this adaptability of the nozzle geometry, the emission characteristics of different lithium-ion batteries upon failure, also referred to as thermal runaway, can be simulated, in particular with regard to the opening angle of the ejection cone (outlet cone), the hot gases and particles of the nozzle outlet passage, the temperature at the point of impact, the overall mass impulse at the impact area, the mass impulse per area, the jet velocity.

[0105] Alternatively, the nozzles 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 nozzles can have an adjustable nozzle geometry, which is preferably also adjustable during application. Thereby, the flow characteristics of the mass flow can be further brought to uniformity during application.

[0106] In an advantageous embodiment of the test device according to the application, the application member is designed as a rocket propellant charge, an acetylene burner with mass feed, a flame spray device, a primary cell or a plasma spray device. A rocket propellant charge can also be referred to as a rocket or rocket engine.

[0107] The rocket propellant charge is preferably a solid composite propellant charge. These solid composite propellant charges have proven to be particularly advantageous, as they provide a more uniform mass flow over the application time and improve the reproducibility due to very small tolerances between the individual thrusters.

[0108] The rocket propellant charge can preferably be activated by electric ignition. This is simple and practical to use and can be implemented with little effort.

[0109] In an advantageous refinement, the primary cell is designed as a secondary cell, also referred to as a storage battery. The primary cell comprises at least one battery cell. The primary cell is particularly preferably designed as a lithium-ion battery. Due to this design of the application member, the test specimen can be tested under quasi-real conditions.

[0110] In an advantageous refinement, the primary cell is preferably arranged such that the mass flow flows out of the primary cell against the force of gravity. This offers the advantage that, with this upright arrangement, no or hardly any flammable liquid electrolyte can escape from the primary cell compared to a hanging arrangement, thus counteracting uncontrolled combustion or even deflagration.

[0111] In an advantageous refinement, the test device and / or the determination device has a data acquisition device. The data acquisition device can be designed, for example, as a computer. The data acquisition device is preferably electrically connected to at least one or all of the aforementioned measuring devices and is set up to record the measuring signals of the measuring devices.

[0112] In an advantageous refinement, a shielding member and / or a deflection device is arranged between the application member and the receptacle.

[0113] Due to the shielding member arranged in this way, it can be ensured that the application member is not damaged or destroyed by the reflection of the mass flow, in particular when there is a small distance between the application member and the test sample. The shielding member is preferably made of a material that is resistant to high temperatures and thermal shocks, preferably made of a fiber composite ceramic.

[0114] The shielding member can preferably be designed as a perforated plate (Lochblende) which has holes through which the mass flow can flow. 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 distance from the application member. The size of the holes is set such that the mass flow can flow unhindered. In a particularly advantageous refinement, the mass flow hits the test sample at an angle, i.e. slightly inclined, so that the majority of the reflection of the mass flow hits the shielding member and the application member is even better protected.

[0115] With this deflection device, the mass flow can be correspondingly deflected when propagating. The deflection device is preferably arranged between the application member and the test sample, in particular the deflection device is arranged on the side of the test sample facing the application member and in the impact portion. The deflection device can be fixed to the test sample, for example, by means of fixing means such as screws. It has been shown that it is particularly advantageous to design the deflection device as a pyramid or wedge. Due to this design of the deflection device, a so-called thermal runaway of a lithium-ion battery can be simulated more realistically than in the prior art. This thermal runaway leads to a rapid and massive ejection of metal battery components, which forms a pyramid-shaped deposit, so that the fast, hot gas is correspondingly deflected. This represents a completely different emission characteristic than a vertical impinging jet. Thus, the described deflection device can be simulated very realistically using the test device according to the application.

[0116] By varying the angle of the deflection device, 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 test sample surface. An angle between the jet direction and the surface normal of the deflection device of between 30° and 45° is advantageous.

[0117] In an advantageous refinement, the deflection device is made of a ceramic material or a metal material, in particular steel, or comprises a ceramic material or a metal material.

[0118] The turning device is preferably designed as a wedge with two surfaces that guide the mass flow, wherein the angle of one surface relative to the sample surface is equal or unequal to the angle of the second surface relative to the sample surface. Thereby, conditions that prevail in reality can be reproduced more precisely on the test device.

[0119] The test device is preferably adapted to carry out the above-described method for testing a sample according to the invention and its improvements, whereby the test device can preferably also have the aforementioned improvements.

[0120] It is noted that the features of the specified improvements and advantageous improvements can be freely combined with each other within the technically possible range, even if this is not explicitly stated in the text. This applies in particular beyond the scope of the device and method claim categories. BRIEF DESCRIPTION OF DRAWINGS

[0121] Further advantages and features of the method according to the invention and the test device according to the invention result from the following embodiments, which will be explained in more detail with reference to the drawings.

[0122] Figure 1 A schematic representation of a first embodiment of a test device according to the invention is shown before applying a high-speed hot mass flow to a sample,

[0123] Figure 2 A schematic representation of a first embodiment of a test device according to the invention is shown during applying a high-speed hot mass flow to a sample,

[0124] Figure 3 A schematic representation of a first embodiment of a test device according to the invention is shown after burn-through of a sample,

[0125] Figure 4a A schematic representation of a force-time chart with a force-time curve resulting from carrying out a method according to the invention is shown,

[0126] Figure 4b A schematic representation of a force-time chart with a force-time curve is shown, wherein a sample survives the application without burn-through,

[0127] Figure 5 A schematic representation of a second embodiment of a test device according to the invention is shown during applying a high-speed hot mass flow to a sample,

[0128] Figure 6 A schematic representation of a second embodiment of a test device according to the invention is shown after burn-through of a sample,

[0129] Figure 7 A schematic representation of a third embodiment of a test device according to the invention is shown during applying a high-speed hot mass flow to a sample,

[0130] Figure 8 a schematic view of a fourth embodiment of a test device according to the application is shown during application of a high-speed hot mass flow to a test specimen,

[0131] Figure 9 a schematic view of a fifth embodiment of a test device according to the application is shown during application of a high-speed hot mass flow to a test specimen,

[0132] Figure 10 a schematic view of a sixth embodiment of a test device according to the application is shown during application of a high-speed hot mass flow to a test specimen,

[0133] Figure 11 a schematic view of a seventh embodiment of a test device according to the application is shown during application of a high-speed hot mass flow to a test specimen,

[0134] Figure 12 a schematic view of an eighth embodiment of a test device is shown during application of a high-speed hot mass flow to a test specimen,

[0135] Figure 13 a schematic view of a ninth embodiment of a test device according to the application is shown during application of a high-speed hot mass flow to a test specimen,

[0136] Figure 14 a schematic sectional view of a nozzle for adjusting the discharge characteristics of a mass flow is shown. DETAILED DESCRIPTION

[0137] In the various figures, identical parts always have the same reference signs and are therefore generally named or referred to only once.

[0138] Figures 1 to 3 A first embodiment of a test device 10 according to the application is shown. The test device 10 is used to test a test specimen 50 using a method according to the application. The test device 10 has a chassis 30; the chassis 30 has a receptacle 32, and the test specimen 50 is accommodated directly in the receptacle 32. An application member 20, which is designed as a rocket engine, is held on a fixed, immovable first support 98, which is shown here schematically as a clamp. The application member 20 is connected to a control unit 90, which is designed as a computer. Figure 1 In the figure, the application member 20 has not yet been ignited, so in Figure 1 The test device before application of a high-speed hot mass flow 22 to the test specimen 50 is shown. The high-speed hot mass flow is referred to hereinafter as mass flow. As can be seen from Figure 2 The application member 20 is aligned to the test specimen 50 such that the mass flow 22 hits the test specimen 50.

[0139] Furthermore, the test device 10 has a determination device designed as a force measuring device 40, which is effectively coupled to the chassis 30. The force measuring device 40 is designed as a force measuring sensor and is accommodated in a packaging housing 42. The force measuring device 40 is held on a second, immovable support 99, so that the force F introduced into the test specimen 50 by the mass flow can be determined. In Figures 1 to 3 In the first embodiment of the test device 10 shown, the plate-shaped test specimen 50 is directly accommodated in the accommodation 32. To this end, the accommodation 32 is designed as an edge portion of the chassis which defines a recess 33, which is stepped, so that the test specimen 50 can be inserted therein securely and, at the same time, is supported against the chassis 30. The test specimen 50 is held on the second, immovable support 99, so that the force F introduced into the test specimen 50 by the mass flow can be determined. In Figure 2 When the mass flow 22 is applied to the test specimen 50 as shown, a support of the test specimen 50 is ensured, so that the force flow is introduced from the test specimen 50 via the accommodation 32 into the chassis 30 and the chassis 30 further transmits the force flow to the force measuring device 40. The test specimen 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. An edge portion of the back side 52 of the test specimen 50 rests on the accommodation 32, wherein the largest area of the back side 52 is not in contact with the accommodation 32, i.e. is contact-free.

[0140] Here, the chassis 30 is designed schematically as a pot-shaped component, preferably made of steel, which has a base portion 34, by which the chassis 30 stands on the force measuring device 40 and is thus effectively coupled to the force measuring device 40, so that a force flow from the chassis 30 to the force measuring device 40 is ensured.

[0141] Figure 2 It is shown that during the application of the mass flow 22 to the test specimen 50 Figure 1 The test device. The supply device 20 provides the mass flow 22 after its electrical ignition for a flow duration predetermined by the properties of the application member 20, which is designed here as a rocket engine with a solid-state composite propellant and is also referred to as application member. The application member 20 is aligned to the test specimen 50, so that the mass flow 22 hits the test specimen 50 in an impact portion 55 of the front side 51 and introduces heat and the force F into the test specimen. The impact portion 55 can 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, whereby the force F is introduced via the accommodation 32 into the chassis 30, which is coupled via the base portion 34 to the force measuring device 40, so that the force F introduced into the test specimen 50 by the mass flow 22 is determined by the force measuring device.

[0142] The method according to the application can be used to determine the time-dependent burnthrough resistance of the test specimen 50 by a determination device, which here comprises a force measuring device. As 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 measuring device 40, so that the time period ts between the start of the application and the occurrence of a force drop based on the burn-through of the specimen 50 is determined.

[0143] Figure 3 is shown after the burn-through of the specimen 50 as Figure 1 and 2 a test device 10 according to the application is shown. From Figure 3 the burn-through result of the specimen 50 can be seen. Due to the thermal input, the mass flow 22 burns through the specimen 50 and creates 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 a very small force is introduced into the specimen 50, so that there is a force drop, which is determined by the force measuring device 40. Thus, by the explained method according to the application, the time period ts between the start of the application and the occurrence of a force drop based on the burn-through of the specimen 50 can be determined. This can be seen better in the force-time diagram from Figure 4a .

[0144] Figure 4a a schematic force-time diagram with a force-time curve is shown, which is determined, for example, by using the method according to the application in one of the test devices according to the application shown in Figures 1 to 3 and Figures 5 to 8 . The force F introduced into the specimen 50 by the mass flow 22 is determined over time t. Such a force-time curve can be determined by the force measuring device 40.

[0145] At the starting point in time t0, which represents the start of the application of the mass flow 22 to the specimen 50, there is a sharp force increase directly to the maximum force F2. Then, the force drops to the force Fl, so that the force introduced by the mass flow 22 remains relatively constant from the point in time tl to the point in time t2. The time period between the points in time t0 and tl shows the starting pulse of the application means 20 designed as a rocket engine. After the occurrence of the starting pulse, the application means designed as a rocket engine provides a constant mass flow 22, which introduces heat and force uniformly and continuously in the specimen 50, so that from the point in time tl to the point in time t2, a substantially constant force acts on the specimen 50. At the point in time t2, the specimen 50 reaches its burn-through resistance with respect to time, so that it starts to burn through at the point in time t2. For example, as Figure 3shown, because the mass flow 22 burns out the opening 58 in the specimen 50 and thus can flow therethrough, and thus no force or a very small force is introduced into the specimen 50, there is a quasi- sharp drop in force from force Fl to force F3 starting from 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 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 of force Fl (force plateau) and the force level of force F3 (force plateau). Thus, the time period ts can be determined as a measure of the time- related burn-through resistance between the start of the application t0 and the occurrence of the force drop based on the burn-through of the specimen 50 at the time point t2. Thus, the time- related burn-through resistance (i.e. the time period ts) can be determined using the method according to the application. Since the mass flow 22 continues to flow for a certain time even after the burn-through and over the edge of the opening 58, a small force F3 is introduced into the specimen 50 even after the burn-through. The following relationship holds: F2 > Fl > F3 > 0. Starting from the time point t4, the force F3 drops to the value 0 at the time point t5 because of the so-called burnout of the application means 20 designed as a rocket engine due to the lack of propellant (fuel).

[0146] Figure 4b A schematic force-time diagram with a force-time curve determined in one of the test devices according to the application shown in Figures 1 to 3 and Figures 5 to 8 is shown. The force F introduced into the specimen 50 by the mass flow 22 is determined over time t, in this case the specimen 50 does not burn through, but survives the application of the mass flow 20. This force-time curve can be determined by the force measuring device 40.

[0147] At the start time point t0, which represents the start of the application of the mass flow 22 to the specimen 50, there is a sharp, direct increase in force to the maximum value F2. This force then drops to the force Fl, so that the force introduced by the mass flow 22 remains relatively constant from the time point tl to the time point t4. The time period between the time points t0 and tl shows the start pulse of the application means 20 designed as a rocket engine. After the start pulse has occurred, the application means designed as a rocket engine provides a constant mass flow 22, which introduces heat and force uniformly and continuously in the specimen 50, so that from the time point tl to the time point t4, a substantially constant force acts on the specimen 50. Starting from the time point t4, the force drops from the force Fl to the value 0 at the time point t5 because of the so-called burnout of the application means 20 designed as a rocket engine due to the lack of fuel. In contrast to Figure 4aThe force curve in the middle is reversed, the specimen 50 did not burn through, so it can be seen that there is no drop in force from F1 to force F3 > 0 due to a burn through. The specimen 50 survived the entire application time (to t5) without burning through. Thus, the time period ts > t5-to.

[0148] Figure 5 and 6 A second embodiment of the test device 10 according to the application is schematically shown, wherein Figure 5 The second embodiment is shown during the application of a high velocity thermal mass flow to the specimen 50, whereas Figure 6 The second embodiment is shown after the specimen has burned through.

[0149] The structure of the second embodiment is based on the test device 10 of the first embodiment, wherein the shown application member 20, the force measuring device 40 and the housing 32 of the chassis 30 as well as the specimen 50 correspond to these components of the test device of the first test device 10 of the first embodiment, so that no redundant explanations are repeated in order to avoid redundancy. All features explained with respect to the mentioned similar components can be transferred.

[0150] In this embodiment, the application member 20 is not supported on a clamp, but on a support beam 73 of a seat frame 70. The seat frame 70 can also be referred to as a frame or support unit. The force measuring device 40 is also mounted on the seat frame 70 and supported thereon, i.e. on a support foot 71 of the seat frame 70.

[0151] The chassis 30 is schematically designed as a pot-like component, which has a base portion 34 by which the chassis 30 stands on the force measuring device 40 of the determination device and is thus effectively coupled to the force measuring device, so that a force flow from the chassis 30 to the force measuring device is ensured. Thus, the chassis 30 can be at least slightly movable with respect to the seat frame 70, so that the force F introduced into the specimen 50 by the mass flow 22 can be determined. In a not shown variant, guiding means can be provided between the seat frame and the chassis, so that the chassis is guided in a manner movable in one direction.

[0152] A baffle 60 is provided within the chassis 30 and at one end of the support arm 72 of the seat frame 70. The support arm 72 extends through a hole-like recess 35 in a side wall of the chassis 30, wherein the support arm 72 protrudes through the hole-like recess 35 with a clearance, so that the baffle 60 is force decoupled from the chassis 30 and thus from the measuring device 40. As can be seen from Figure 6It is clearly visible that the baffle 60 is inclined, i.e. arranged at an angle, with respect to the front side 51 of the test specimen 50, so that in the event of burn-through the mass flow 22 flowing through the opening 58 of the test specimen 50 is aligned to the suction device. The inclination of the baffle with respect to the front side 51 of the test specimen 50 is preferably between 30° and 60°. The intake opening 65 of the suction device is shown here in a schematic manner. This intake opening 65 passes through a further recess in a further side wall of the chassis 30.

[0153] An infrared camera 84 is arranged on the support arm 72, which is aligned to the back side 52 of the test specimen 50 and records a thermal image of the back side 52 of the test specimen 50 when the mass flow 22 is applied to the test specimen 50. The infrared camera 84 is attached to the support arm 72 in an adjustable manner. The infrared camera 84 forms part of the determination device.

[0154] 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. This temperature measuring device 81 is designed as a thermocouple and is bonded to the back side 52 of the test specimen.

[0155] A first high-speed camera 82 with a filter 821 and a second high-speed camera 83 are attached to the seat frame 70 and their orientation is adjustable. The high-speed cameras 82, 83 form part of the determination device. The first high-speed camera 82 is aligned to the impact portion 55 of the mass flow 22. The second high-speed camera 83 is aligned to the mass flow 22 and its impact portion 55 as well as to the test specimen 50. However, it can also be arranged such that the application member 20 is also recorded. Both high-speed cameras obtain a video recording of the application process.

[0156] Figure 7 A third embodiment of the test device 10 according to the application is shown schematically, which shows the third embodiment during the application of a high-speed thermal mass flow 22 to the test specimen 50.

[0157] 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 accommodation 32 of the chassis 30 correspond to those of the second embodiment, so that no further explanation is given to avoid redundancy. All features explained with respect to the mentioned similar components can be transferred.

[0158] The structure of the seat frame 70 and its function are similar to the seat frame 70 of the second embodiment of Figure 5 and 6 , wherein the support beam 73 carrying the application member 20 is adjustable in the height direction H by means of the first adjustment device 77. Thus, the distance of the application member 20 to the accommodation 32 and thus to the test specimen 50 can be adjusted.

[0159] The application member 20 is accommodated in a blind hole opening of the support element 90. The support element 90 is designed as a tube which is closed on one side. The support element 90 has a locking device (not shown) which fixes the application member 20 relative to the support element 90, so that the application member 20 cannot fall out of the support element 90.

[0160] The support element 90 is held pivotally in the pivot direction W by a lockable joint 92 on the support beam 73 of the holder 70, so that the angle of the application member 20 relative to the accommodation 32 and thus relative to the test specimen 50 is adjustable, so that the mass flow 22 can also impinge on the front side 51 of the test specimen 50 at an angle. The adjustable angle is preferably between 0° and 60°, particularly preferably between 0° and 45°. As shown, an angle of 0° corresponds to a mass flow 22 which goes orthogonally to the accommodation 32 or the test specimen 50. Figure 7

[0161] 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 holder 70, so that the support element 90 can be adjusted in a manner parallel to the accommodation 32 or the test specimen 50, so that, depending on the set angle of the support element 90 and the application member 20 accommodated therein, it can be adjusted so that the mass flow 22 is directed to the accommodation 32 or the test specimen 50, preferably so that the mass flow 22 impinges on the center of the test specimen 50.

[0162] The first adjustment device 77 can be designed as a manual, electric, pneumatic or hydraulic adjustment device. The second adjustment device 78 can also be designed as a manual, electric, pneumatic or hydraulic adjustment device.

[0163] A first high-speed camera 82 with a filter 821 and a second high-speed camera 83 are attached to the holder 70, and their respective orientations are adjustable. The first high-speed camera 82 is aligned with the impact 55 of the mass flow 22. The second high-speed camera 83 is aligned with the mass flow 22 and its impact 55 as well as the test specimen. However, it can also be arranged so that the application member 20 is also recorded. Both high-speed cameras obtain a video recording of the application and form part of the determination device for testing the test specimen.

[0164] An infrared camera 84 is arranged on the support arm 72 of the holder 70 and is constructed and arranged as in the second embodiment.

[0165] ​A baffle 60 is arranged within the chassis 30 and is adjustable in its position and angular orientation at one end of the support arm 72 of the holder 70. The support arm 72 extends through a hole-like recess in a side wall of the chassis 30 such that the recess is force decoupled from the chassis 30. The baffle 60 is inclined with respect to the front side 51 of the test specimen 50 such that in the event of a burn-through the mass flow 22 flowing through the opening in the test specimen 50 is directed to the suction device. Preferably, the inclination of the baffle with respect to the front side 51 of the test specimen 50 is adjustable between 30° and 60°. An air inlet 65 of the suction device is shown here schematically. This air inlet 65 passes through a further recess in a further side wall of the chassis 30.

[0166] 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.

[0167] In contrast to the first two embodiments, the test specimen 50 is not directly accommodated in the accommodation 32 of the chassis 30, but is indirectly accommodated in the accommodation 32 of the chassis 30. To this end, a test specimen holder 38 for accommodating the test specimen 50 is provided, which is accommodated in the accommodation 32. The test specimen holder 38 preferably has a grid 59, which is placed like a hood over the test specimen 50. Thus, the test specimen 50 is firmly held on the test specimen holder 38. The test specimen holder 38 is designed in a frame-like manner, so that the test specimen 50 can be inserted therein.

[0168] A first fixing device 37 is provided for fixing the test specimen holder 38 in the accommodation 32 and is designed as a clamping lever here. This fixing device 37 can be switched between a fixing position and a release position, so that in the fixing position the test specimen holder 38 is fixed with respect to the accommodation 32 and in the release position the test specimen holder 38 can be accommodated in or removed from the accommodation 32.

[0169] Furthermore, a second fixing device 39 for fixing the test specimen 50 on the test specimen holder 38 is provided, which is designed as a screw element and is shown schematically.

[0170] Furthermore, the test device 10 has a data acquisition device 100, which is designed as a computer and can also be referred to as a measurement computer. The data acquisition device 100 is electrically connected to all the above-mentioned measuring devices and is provided to record the measurement signals from the measuring devices. That is to say, the data acquisition device 100 is connected via data lines 101 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. This data line 101 can be designed as a data bus.

[0171] In a variant not shown, it is also conceivable and possible that the first and second adjustment devices 77 and 78 each have a position sensor and / or are controlled by means of a data acquisition device in the case of a non-manual design.

[0172] Furthermore, the data acquisition device 100 can be used for the electric ignition of the application member 20 and thus the start of the recording of the measurement results.

[0173] Figure 8 A fourth embodiment of the testing device 10 according to the application is shown during the application of a high-speed thermal mass flow 22 to the test specimen 50.

[0174] This fourth embodiment largely corresponds to the first embodiment shown in Figures 1 to 3 but is supplemented by a shielding member 24 designed as a perforated plate, which is arranged between the application member 20 and the housing 32. Furthermore, in contrast to the first embodiment, the mass flow 22 does not impinge on the test specimen 50 completely perpendicularly, since the chassis 30 is slightly inclined. Thus, the majority of the mass flow 22 is reflected and impinges on the shielding member 24 and the application member 20 is sufficiently well protected against damage. The shielding member 24 designed as a perforated plate 24 is made of a material that is resistant to high temperatures and thermal shocks. The shielding member 24 has holes 26 through which the mass flow 22 can flow. The shielding member 24 designed as a perforated plate is mounted directly on the application member 20, so that the holes 26 are designed to correspond to the nozzles of the application member 20. In an alternative embodiment not shown, the shielding member can be arranged at a distance from the application member. In this case, the size of the holes is set such that the mass flow can flow unhindered. All other aspects of the testing device 10 of the fourth embodiment correspond to the first embodiment and, in order to avoid redundancy, are not repeated here.

[0175] Figure 9 A schematic view of a fifth embodiment of the testing device according to the application is shown during the application of a mass flow to a test specimen.

[0176] The structure of the fifth embodiment is based on the testing device 10 of the second embodiment, but the only difference is that Figure 9A fifth embodiment of the application comprises an acoustic measuring device 85 which is designed as a microphone. By means of the acoustic measuring device 85, recordings can be made during the application of the mass flow 22 to the test specimen 50, so that additional information about the application process can be determined. For example, the ignition point of time to of the application member 20 can be determined precisely by means of the acoustic measuring device 85. Furthermore, the point of time at which the test specimen 50 is burnt through can also be determined by means of the acoustic measuring device. The acoustic measuring device is thus part of the determination device. This provides a redundancy for other similar measuring devices, such as force measuring devices and cameras, which are also based on different measuring principles. Furthermore, the acoustic measuring device has the advantage that, unlike a camera, its measuring performance is not impaired by the production of smoke during the application. The acoustic measuring device can also form the determination device without other measuring devices. In other words, the burn-through resistance of the test specimen with respect to time can be determined by means of the acoustic measuring device alone.

[0177] Figure 5 The features of all other explanations of the second embodiment in Figure 9 the fifth embodiment can be transferred without limitation to

[0178] Figure 10 A schematic representation of a sixth embodiment of the test device 10 according to the application is shown during the application of a high-speed thermal mass flow 22 to the test specimen 50.

[0179] The test device 10 comprises a chassis 30 with a receptacle 32 in which the test specimen 50 is accommodated directly. The receptacle 32 is designed as an edge portion of the chassis 30 which defines a recess 33, wherein the edge portion is stepped such that the test specimen 50 can be inserted therein securely. The application member 20, which is designed as a primary cell, in particular as a lithium-ion cell, is held in a fixed, immovable first holder 98, which is shown here schematically as a support frame 79, and is fixed on a clamping device. The support frame 79 extends through a hole-like recess 35 in a side wall of the chassis 30, the support frame 79 protruding through the hole-like recess 35 with a clearance, so that a force decoupling of the application member 20 from the chassis 30 and thus from the measuring device 40 is ensured.

[0180] The mass flow 22 is provided by the application member 20. The application member 20 is aligned to the test specimen 50 such that the mass flow 22 hits the test specimen 50 in an impact portion 55 of the front side 51 and introduces heat and a force F therein. The impact portion 55 can 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 transmits the force F via the fixing device 37, which is designed as a screw, and the receptacle 32 into the chassis 30, which is coupled via the base portion 34 to the force measuring device 40, so that the force F introduced by the mass flow 22 into the test specimen 50 is determined by means of the force measuring device.

[0181] The time-dependent burn-through resistance of a test specimen 50 can be determined using the method according to the application. As can be seen from Figure 10 the high-speed thermal mass flow 22 from the primary cell 20 is applied to the test specimen 50 and the force F acting on the test specimen 50 as a result of the application is continuously determined by the force measuring device 40, so that the time period ts between the onset of the application and the occurrence of a drop in the force based on the burn-through of the test specimen 50 is determined. Additionally or alternatively, the determining device can also comprise other or further measuring devices.

[0182] The application member 20 is arranged within the chassis 30 such that the mass flow 22 flows out of the primary cell element against the force of gravity, i.e. upwards. This provides the advantage that, in contrast to a hanging arrangement, no or hardly any flammable liquid electrolyte can escape (leak) from the primary cell 20 in this upright arrangement and thus uncontrolled burning or even deflagration is counteracted.

[0183] The test device 10 has a force measuring device 40 which is effectively coupled to the chassis 30. This force measuring device 40 is accommodated in an encapsulation housing 42. The force measuring device 40 is held on a second, immovable mount 99, so that the force F introduced into the test specimen 50 by the mass flow can be determined.

[0184] 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, 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.

[0185] Figure 11 A schematic representation of a seventh embodiment of the test device according to the application is shown during the application of a high-speed thermal mass flow to a test specimen.

[0186] The structure of the seventh embodiment is based on the test device 10 of the second embodiment, but the only difference is that Figure 11 The seventh embodiment comprises an exhaust fan device 67. The exhaust fan device has a compressed air lance 69 which is fixed in a seat 70 and is connected to a compressed air hose 68 which is connected to a compressor (not shown). The exhaust fan device 67 is set up and arranged such that it removes the smoke produced during the application by means of an air flow. The advantage of this is that the field of view of the test specimen remains clear during the application when a high-speed camera is used and is not affected by the smoke. The test accuracy of the test specimen can thus be further improved, in particular when a high-speed camera is used to determine the time-dependent burn-through resistance. The size of the fluid flow must be set such that it has a negligible and technically negligible influence on the mass flow during the application.

[0187] Figure 5 All other features of the second embodiment can be transferred to the seventh embodiment without restriction. Figure 11the seventh embodiment.

[0188] Figure 12 a schematic view of a ninth embodiment of the testing device according to the present application during the application of a high velocity thermal mass flow to a test sample is shown.

[0189] The structure of the eighth embodiment is based on the testing device 10 of the seventh embodiment, but the only difference is that Figure 12 The eighth embodiment does not comprise a force measuring device. The determining device for determining the time related burn-through resistance comprises high speed cameras 82 and 83 which determine the time period ts using the method according to the present application.

[0190] Figure 11 all other features of the seventh embodiment Figure 5 The features described in relation to the second embodiment can be transferred to the Figure 12 the eighth embodiment without limitation.

[0191] Figure 13 a schematic view of a ninth embodiment of the testing device according to the present application during the application of a high velocity thermal mass flow to a test sample is shown.

[0192] The structure of the ninth embodiment is based on the testing device 10 of the first embodiment, but the only difference is that Figure 13 The ninth embodiment comprises a deflection device 25.

[0193] From Figure 13 It can be clearly seen that by the deflection device 25 designed as a wedge the mass flow 22 can be correspondingly deflected when it propagates. The deflection device 25 designed as a wedge is arranged between the application member 20 and the test sample 50, in particular between the application member and the side 51 of the test sample 50 facing the application member 20. The deflection device 25 is fixed to the test sample by means of screws not shown. The deflection device 25 is made of steel. The deflection device 25 designed as a wedge has two surfaces guiding the mass flow, wherein the angle of one surface relative to the test sample surface is equal to the angle of the second surface relative to the test sample surface. Thereby, conditions prevailing in reality can be reproduced more precisely on the testing device. When the mass flow 22 hits the deflection device 25, it is substantially halved and correspondingly deflected laterally. The effect of the deflection device is like a plow. The deflection device 25 can easily be combined into the other embodiments.

[0194] Figure 14A schematic longitudinal cross-sectional view of a nozzle 21 is shown. This nozzle 21 can be combined to 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 with a predetermined length 212, a predetermined opening cross section 213 and a predetermined opening angle a. The opening cross section 213 here denotes the cross section from the supply line to the inlet of the nozzle outlet channel. Due to the taper angle, the final outlet cross section can easily be determined by calculation. The wall of the outlet channel can be curved, for example convex or concave.

[0195] In principle, the measuring devices, cameras and all other advantageous refinements shown in the other embodiments can also be transferred to Figure 10 the test device shown.

[0196] List of reference signs

[0197] 10 test device

[0198] 20 application member

[0199] 21 nozzle

[0200] 22 mass flow

[0201] 24 shielding member

[0202] 25 turning device

[0203] 26 hole

[0204] 30 chassis

[0205] 32 receptacle

[0206] 33 recess

[0207] 34 base portion

[0208] 35 hole-like recess

[0209] 37 first fixing device

[0210] 38 sample holder

[0211] 39 second fixing device

[0212] 40 force measuring device

[0213] 42 packaging housing

[0214] 50 sample

[0215] 51 front side

[0216] 52 back side

[0217] 55 impact portion

[0218] 58 opening

[0219] 59 grid

[0220] 60 baffle

[0221] 65 air intake of the extraction device

[0222] 67 extraction fan device

[0223] 68 compressed air hose

[0224] 69 compressed air lance

[0225] 70 seat

[0226] 71 support foot

[0227] 72 support arm

[0228] 73 support beam

[0229] 77 first adjustment device

[0230] 78 second adjustment device

[0231] 79 support frame

[0232] 81 temperature measuring device

[0233] 82 first high-speed camera

[0234] 821 filter

[0235] 83 second high-speed camera

[0236] 84 infrared camera

[0237] 85 acoustic measuring device

[0238] 90 support element

[0239] 92 joint

[0240] 98 first bearing

[0241] 99 second bearing

[0242] 100 data acquisition device

[0243] 101 data line

[0244] 211 nozzle outlet channel

[0245] 212 length

[0246] 213 opening cross section

[0247] α opening angle

[0248] t0 start time point

[0249] ts time period that is a measure of burn-through resistance with respect to time.

Claims

1. A method for thermomechanical testing of a test specimen (50), wherein, Applying a high-speed thermal mass flow (22) to the test specimen (50), characterized in that the force (F) acting on the test specimen (50) as a result of the application is determined continuously by a determination device, and a force-time curve is determined by the determination device, wherein the time period (ts) between the start of the application and the occurrence of a force drop based on a burn-through of the test specimen (50) is determined.

2. The method of claim 1, wherein, The point in time (t0) of the start of the application is determined by a force increase.

3. The method according to claim 1 or 2, characterized in that, The temperature of the test specimen (50) is determined.

4. The method of claim 3, wherein, The temperature is determined on the back side (52) of the test specimen (50) facing away from the mass flow (22).

5. The method of claim 3, wherein, The determination of the force and / or the temperature is carried out in a common data acquisition device (100).

6. The method according to claim 1 or 2, characterized in that, The pulse acting on the test specimen (50) is determined by the force (F) acting over the time period (ts).

7. The method according to claim 1 or 2, characterized in that, A thermal image and / or thermograph of the test specimen (50) is recorded, and / or an acoustic signal is determined during the application, and / or a jet velocity of the mass flow (22) is determined.

8. The method of claim 1 or 2, wherein, The mass flow (22) is provided by a rocket propellant charge, an acetylene burner with mass feed, a flame spray or a plasma spray.

9. A testing device (10) for thermomechanical testing of a test specimen (50), comprising a chassis (30) having a receptacle (32) in which the test specimen (50) can be accommodated directly or indirectly, and an application member (20) for providing a high-speed thermal mass flow (22) that can be directed onto the test specimen (50), characterized in that The test device (10) has a determination device which comprises a force measuring device (40) which is operatively connected to the chassis (30) and is designed to determine the force (F) introduced into the test specimen (50) by the mass flow (22) in order to determine a force-time curve, wherein the time period (ts) between the start of the application means and the occurrence of a force drop based on a burn-through of the test specimen (50) is determined.

10. The testing device (10) according to claim 9, characterized in that The determination device is designed to determine the burn-through resistance of the test specimen (50).

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

12. The test device (10) according to any one of claims 9 to 11, characterized in that The determination device comprises a temperature measuring device (81) for determining the temperature of the test specimen (50) and / or a high-speed camera (82, 83) and / or an infrared camera (84) and / or an acoustic measuring device (85).

13. The test device (10) according to any one of claims 9 to 11, characterized in that The application means (20) are adjustable relative to the chassis (30).

14. The testing device (10) according to claim 13, characterized in that The angle and / or the distance of the application means (20) relative to the chassis (30) are adjustable.

15. The test device (10) according to any one of claims 9 to 11, characterized in that The application means (20) are designed as a rocket propellant charge, an acetylene burner with mass feed, a flame spray device, a galvanic cell or a plasma spray device.

16. The test device (10) according to any one of claims 9 to 11, characterized in that Between the application means (20) and the housing (32) there is arranged a shielding means (24) and / or a deflection device (25).

17. A test device (10) for carrying out a method for testing a test sample (50) according to any one of claims 1 to 8, characterized in that The test device (10) is designed according to the test device of any one of claims 9 to 16.

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