High-pressure environmental device for testing mechanical properties of materials

Abstract

A test device for testing the mechanical properties of material samples in a pressure test environment, comprising: a first fluid chamber for receiving a first fluid; a second fluid chamber for receiving a second fluid to provide a pressure testing environment; a first disc-shaped separating membrane separating the first fluid chamber from the second fluid chamber and fixedly mounted to the first fluid chamber and the second fluid chamber; a first fluid equalization chamber in fluid communication with the first fluid chamber; a second fluid equalization chamber in fluid communication with the second fluid chamber; a second disc-shaped separating diaphragm separating the first fluid equalization chamber from the second fluid equalization chamber and fixedly mounted to the first fluid equalization chamber and the second fluid equalization chamber; a loading rod extending through the wall of the first fluid chamber and the first disc-shaped separation membrane to exert a predetermined force on the material sample in the second fluid chamber; a sealing element which is firmly connected to the wall of the first fluid chamber, to guide the load rod slidably and tightly through the wall of the first fluid chamber; and a sealing component fixedly mounted to the load rod and the first disc-shaped separating diaphragm to seal the first fluid chamber and the second fluid chamber.

Description

Technical FieldThe present invention relates to the technical field of devices for investigating mechanical properties of materials, in particular a testing device with a high-pressure chamber for carrying out material-mechanical tests in high-pressure ambient media.Prior ArtThe mechanical properties of materials are normally tested in a laboratory with the aid of a testing machine to stressfully on material samples, such as tensile, compressive and fracture toughness tests. The mechanical properties of the material are measured and tested under certain ambient conditions or a medium.When it is concerned with examining the influence of a certain environment on the mechanical properties of a material, it is usual to install an environment box around the load unit of the testing machine and place the material sample and the load device in the environment box. During the test, the ambient medium, temperature and pressure in the box are controlled to effect the test of the material under certain ambient conditions.As hydrogen as a clean energy source appears, the demand for testing materials in a high hydrogen pressure environment is continually increasing. For example, hydrogen embrittlement of metals and other materials is a known problem. Hydrogen embrittlement can impair the construction and operation of hydrogen generation, transport and use equipment. In order to better understand the effect of hydrogen embrittlement, it is necessary to conduct tests on materials in an environment of high hydrogen pressure. Such tests can be very time consuming, for example over 1,000 hours or even longer. The existing material testing techniques present challenges in at least the following three aspects. First, it is difficult to prevent hydrogen at high pressure from being broken out from the test environment box because hydrogen is the smallest molecules and the stress rod normally penetrates the wall of the environment box at high pressure. It is impossible to completely seal the surrounding chamber. In addition, hydrogen accelerates the aging process of all sealing elements mounted on the wall of the chamber and significantly reduces their useful life. Second, the lubricants at the interface between the load bar and the environmental box are prone to contaminate the hydrogen environmental medium in the test chamber, resulting in undesirable changes in the environment in the chamber. Third, the seal must be highly pressure tight in the area of contact between the load rod and the wall of the surrounding box to prevent hydrogen leakage. As a result, the load rod is influenced by a high frictional resistance during its movement. This uncertain frictional resistance may impair the accuracy of the test results and even result in the test data becoming invalid because it is difficult to accurately measure the force the load bar applies to the material sample to be tested. For these reasons, it is necessary to improve the existing techniques and develop new techniques.U.S. Patent No. 8,444,935 describes a sample inspection system consisting of a pair of fluid chambers, each fluid chamber being separated by a membrane. However, this system does not show a design of a load rod which penetrates the membrane and the top wall of the fluid chamber and is used to load the material sample.Content of the Utility ModelThe present invention provides an improved test apparatus for testing the mechanical properties of material samples in a pressure testing environment. In some embodiments, the test apparatus is comprised of: a first fluid chamber for receiving a first fluid; a second fluid chamber for receiving a second fluid to provide a pressure test environment; a first disk-shaped isolation membrane separating the first fluid chamber from the second fluid chamber and fixedly mounted to the first fluid chamber and the second fluid chamber; a first fluid compensation chamber in fluid communication with the first fluid chamber; a second fluid compensation chamber in fluid communication with the second fluid chamber; a second disk-shaped isolation membrane separating the first fluid compensation chamber from the second fluid compensation chamber and fixedly mounted to the first fluid compensation chamber and the second fluid compensation chamber; a load rod extending through the wall of the first fluid chamber and the first disk-shaped isolation membrane to apply a load to the material sample in the second fluid chamber; a sealing member fixedly connected to the wall of the first fluid chamber to allow the load rod to slide through the wall of the sealing chamber; and a sealing component fixedly mounted to the load rod and the first disk-shaped separation membrane to seal the first fluid chamber from the second fluid chamber. Moreover, the first fluid chamber communicates with the first fluid balance chamber, and the second fluid chamber for material testing communicates with the second fluid balance chamber.The design of the test apparatus disclosed by the present invention provides a design method for a high pressure environment test chamber with high stability suitable for testing the mechanical properties of materials in a high pressure environment. The design comprises two flexible disk-shaped separation membranes and four chambers. The test apparatus of the present invention solves the problems encountered in the existing art, such as poor tightness, easy and unintentional leakage and contamination of the test environment medium, as well as the relatively high frictional resistance on the load rod, which results in that the load cannot be accurately transferred to the material sample, and so on.Since the first disk-shaped separation membrane separates the first fluid chamber from the second fluid chamber and the sealing component is fixedly mounted with the load rod and the first disk-shaped separation membrane, the second fluid chamber (also referred to as a test chamber) is completely separated from the first fluid chamber and has good tightness. This structure can not only prevent the leakage of the second fluid (also referred to as a test environment medium such as hydrogen) but also effectively prevent the leakage of the first fluid (e.g., the hydraulic oil or the lubricating oil in the first fluid chamber) into the test chamber. This prevents contamination of the surrounding medium in the test chamber by hydraulic oil, lubricating oil or other fluids. As described herein, those skilled in the art can understand that both lubricating oil and hydraulic oil are suitable for the first fluid chamber and the corresponding first fluid balancing chamber of the apparatus. In the present specification, when the word "hydraulic oil" is used in the description of an application example of the inspection device, it may be replaced with "lubricating oil". Also, the word "lubricating oil" when used in describing an application example of the inspection device may be replaced with "hydraulic oil".The second disk-shaped separation membrane in the present design structure, which separates the first fluid balancing chamber from the second fluid balancing chamber, may deform in synchronization with the pressure changes in the first fluid chamber and the second fluid chamber. Thus, pressure fluctuations and pressure imbalance in the first fluid chamber and the second fluid chamber can be avoided, and thus the additional force on the load rod caused by the pressure difference on both sides of the separation membrane can be eliminated. Thus, the load that the load bar applies to the material sample can be accurately determined, and the accuracy of measurement of the mechanical properties of the sample to be tested can be improved.On the other hand, the testing apparatus for testing mechanical properties of material samples in a pressure testing environment in the present invention comprises: a first fluid chamber for accommodating a first fluid; a second fluid chamber for accommodating a second fluid to provide a pressure testing environment; a first disk-shaped separation membrane separating the first fluid chamber from the second fluid chamber and fixedly mounted with the first fluid chamber and the second fluid chamber; a first fluid compensation chamber fluidly connected with the first fluid chamber; a second fluid compensation chamber fluidly connected with the second fluid chamber; a second disk-shaped separation membrane separating the first fluid compensation chamber from the second fluid compensation chamber and fixedly mounted with the first fluid compensation chamber and the second fluid compensation chamber; a load rod extending through the wall of the first fluid chamber and the first disk-shaped separation membrane to apply a load to the material sample in the second fluid chamber; a sealing member fixedly connected to the wall of the first fluid chamber to allow the load rod to slide therethrough; and a sealing component fixedly mounted to the load rod and the first disk-shaped separation membrane to seal the first fluid chamber and the second fluid chamber.In some embodiments of the test apparatus, the sealing component includes: a lower sealing plate disposed below the first disk-shaped separation membrane and fixedly and seamlessly mounted on the stress rod; at least one first sealing plate mounted between the lower sealing plate and the first disk-shaped separation membrane; an upper sealing plate disposed above the first disk-shaped separation membrane and fixedly mounted with the lower sealing plate and the first disk-shaped separation membrane; and at least one second sealing plate mounted between the upper sealing plate and the first disk-shaped separation membrane.In some embodiments, the lower seal disk is welded to the load rod. In other embodiments, the lower sealing washer and the load rod may be manufactured as a one-piece component. In some embodiments, the upper seal plate, the first disk-shaped separation membrane, and the lower seal plate are fixedly mounted by a plurality of fasteners.In some embodiments, at least one of the first seal plates and at least one of the second seal plates form an inner seal plate disposed between the plurality of fasteners and the load rod, and at least one of the first seal plates and at least one of the second seal plates form an outer seal plate disposed between the plurality of fasteners and the outer edges of the upper and lower seal plates.In some embodiments of the test apparatus, the first fluid is oil and the second fluid is hydrogen. In some embodiments, the second fluid chamber is below the first fluid chamber and the second fluid compensation chamber is below the first fluid compensation chamber. In some embodiments, each of the first fluid chamber, the second fluid chamber, the first fluid balancing chamber, and the second fluid balancing chamber is cylindrical.In some embodiments of the test apparatus, a material sample support structure is fixedly mounted on the inner surface of the wall of the second fluid chamber. In some embodiments, the test apparatus further comprises a first connection pipe fluidly connecting the first fluid chamber to the first fluid compensation chamber and a second connection pipe fluidly connecting the second fluid chamber to the second fluid compensation chamber. In some embodiments, a first inlet pipe is connected to the inlet of the first fluid chamber and a first outlet pipe is connected to the outlet of the first fluid balancing chamber. In some embodiments, a second inlet pipe is connected to the inlet of the second fluid chamber and a second outlet pipe is connected to the outlet of the second fluid balancing chamber. In some embodiments, each of the first inlet pipe and the first outlet pipe includes a valve to control the flow of the first fluid through the first inlet pipe and the first outlet pipe. In some embodiments, each of the second inlet pipe and the second outlet pipe includes a valve to control the flow of the second fluid through the second inlet pipe and the second outlet pipe.In some embodiments of the test apparatus, each of the first fluid chamber, the first fluid compensation chamber, the second fluid chamber, and the second fluid compensation chamber has a flange protruding outward from the chamber, such that the first fluid chamber is fixedly mounted to the second fluid chamber by a first group of fasteners inserted into the respective flanges of the first and second fluid chambers, and the first fluid compensation chamber is fixedly mounted to the second fluid compensation chamber by a second group of fasteners inserted into the respective flanges of the first and second fluid compensation chambers.In some embodiments of the test apparatus, at least one isolation membrane sealing disk is clamped between each of the first disk-shaped isolation membrane and the second disk-shaped isolation membrane and the corresponding first or second fluid chamber or the corresponding first or second fluid compensation chamber.In some embodiments, a set of support feet is used to stably support at least the second fluid chamber and the second fluid compensation chamber on a surface. In some exemplary embodiments, at least one connecting element is used to connect at least the second fluid chamber stably to a material testing machine.DESCRIPTION OF THE ACCOMPANYING DRAWINGSThe embodiments of the test apparatus in the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a three-dimensional side view of an embodiment of the test apparatus of the present invention; FIG. 2 is a cross-sectional isometric view of the test apparatus of FIG. 1 ; FIG. 3 is a local isometric sectional view of the test apparatus of FIG. 1 showing the first fluid chamber and the second fluid chamber; FIG. 4 is a cross-sectional isometric view of another portion of the test apparatus in FIG. 1 is a view showing the first fluid balancing chamber and the second fluid balancing chamber; FIG. 5A is an enlarged sectional view taken along the section A-A in FIG. 2, showing the sealing component of the test apparatus in FIG. 1 ; FIG. 5B is an overall sectional view of another embodiment of the sealing component of the test apparatus of the present invention; FIGS. 6A and 6B are a top view of an embodiment of the upper seal washer and the lower seal washer used in the seal component in FIG. 5, respectively; FIG. 7 is a sectional view of the second fluid chamber in which a support structure for supporting the material sample is provided; and FIG. 8 is a cross-sectional view of another embodiment of the second fluid chamber in which another type of support structure is provided to support the material sample.The following list indicates all components and their corresponding reference numerals used in all figures of an exemplary embodiment of the present invention. They will be discussed in detail below:1-First fluid chamber; 2-Second fluid chamber; 3-First fluid compensation chamber; 4-Second fluid compensation chamber; 5-First disk-shaped separation membrane; 6-Second disk-shaped separation membrane; 7-Load rod; 8-Support structure; 9-Material sample; 10-First connection tube; 11-Second connection tube; 12-Connection head; 13-Support foot; 14-Connection rod; 15-Foot pad; 16-First chamber pin assembly; 17-Second chamber pin assembly; 18-First fluid inlet tube; 19-Second fluid inlet tube; 20-First fluid outlet tube; 21-Second fluid outlet tube; 22-Sealing element; 23-Upper sealing disk; 23a-Outer edge of the upper sealing disk; 24-Lower sealing disk; 24a-Outer edge of the lower sealing disk; 25-pin assembly; 26-First separation membrane seal; 27-Second separation membrane seal; 28a inner seal; 28b outer seal; 30 seal component; 31 chamber wall flange; 32 support clamp; and 34 connecting rod.Exemplary EmbodimentsFIGS. 1-8 show exemplary embodiments of a testing environment device for testing the mechanical properties of materials in a printing testing environment. Material mechanical tests that may be performed with the surrounding device described herein include, but are not limited to, tensile, compressive, bending, hardness, fatigue, and fracture toughness tests.Referring to Figs. 1 to 5, the test environment apparatus includes a high pressure test chamber. In the test chamber, the material sample is supported and a force is applied to the material sample with a load rod to measure its mechanical properties. More specifically, the inspection apparatus includes a first fluid chamber 1 for accommodating a first fluid; a second fluid chamber 2 for accommodating a second fluid; a first disk-shaped separation membrane 5 that separates the first fluid chamber 1 from the second fluid chamber 2; a first fluid compensation chamber 3 that is in fluid communication with the first fluid chamber; a second fluid compensation chamber 4 that is in fluid communication with the second fluid chamber 2; a second disk-shaped separation membrane 6 that separates the first fluid compensation chamber 3 from the second fluid compensation chamber 4; a load rod 7 that passes through the wall of the first fluid chamber 1 and the first disk-shaped separation membrane 5 to apply a predetermined force to the material sample 9; a sealing member 22 (e.g., a seal ring) that is fixedly connected to the wall of the first fluid chamber 1 to allow the load rod 7 to slide through the chamber wall; and a sealing component 30 fixedly mounted with the load rod 7 and the first disk-shaped separation membrane 5 to seal the first fluid chamber from the second fluid chamber.In this embodiment, the first fluid chamber 1 and the first fluid compensation chamber 3 are filled with a first fluid; in an exemplary embodiment, the first fluid may be hydraulic oil or lubricating oil. The second fluid chamber 2 and the second fluid compensation chamber 4 are filled with a second fluid used to provide a pressurized material testing environment to test the properties of the material. In an exemplary embodiment of the test apparatus, the second fluid may be hydrogen. It is to be understood, however, that other test fluids, such as other gases or liquids, may also be used in the test apparatus to test the mechanical properties of materials in a particular environment. Throughout the present text, hydraulic oil or lubricating oil is used as an example of the first fluid and hydrogen is used as an example of the second fluid to describe the principle and operation of the novel test apparatus and provide material testing in a pressurized hydrogen environment; however, the examples of using hydraulic oil or lubricating oil and hydrogen in the test apparatus are not limiting. It is to be understood that fluids other than first and second fluids may be used in the test apparatus. The material sample 9 to be tested may be placed in the hydrogen environment of the second fluid chamber 2 under a predetermined pressure to test various mechanical properties. For example, the predetermined pressure may be up to 1.45 ksi or 10 MPa, which is a typical pressure range for testing the material properties of tubing steel samples. However, the above pressure range is not restrictive. It will be understood that the test apparatus disclosed herein can be configured, if necessary, to test materials under higher pressure.On the other hand, the second fluid chamber 2 filled with hydrogen is located below the first fluid chamber 1 filled with hydraulic oil (or lubricating oil). The first fluid balance chamber 3 communicating with the first fluid chamber 1 communicates with the first fluid chamber 1. The second fluid balance chamber 4 communicating with the second fluid chamber 2 is located below the first fluid balance chamber 3. The advantage of the cylindrical shape is that under the pressure in the chamber a uniform internal tension can be achieved in the chamber wall. However, it will be understood by those skilled in the art that these chambers are not limited to cylindrical geometry; other shapes of chambers may also be used, including spheres, cubes, cones, etc.The hole through which the loading rod 7 passes is best situated in the middle of the upper wall of the first fluid chamber 1. the sealing element 22, for example a conventional sealing ring as known to those skilled in the art, is firmly connected to the hole portion in the upper wall of the first fluid chamber, so that the loading rod 7 slides over the sealing ring 22 and passes through the chamber wall. This design enables not only the seal ring 22 to prevent the leakage of lubricating oil or hydraulic oil, but also the lubricating oil to reduce the frictional force between the seal ring 22 and the load rod 7, thereby improving the durability of the inspection apparatus and the accuracy of measurement of the load exerted by the load rod 7.In another aspect, as shown in FIG. 5, the sealing component 30 further seals the hydraulic oil in the first fluid chamber 1 and seals the hydrogen in the second fluid chamber 2, so that the hydraulic lubricating oil in the first fluid chamber 1 and the hydrogen in the second fluid chamber are separated from each other. This sealing component 30 can significantly prevent the leakage of hydraulic oil into the second fluid chamber 2, thereby preventing the contamination of the test environment medium in the second fluid chamber 2, and can also prevent the leakage of hydrogen from the second fluid chamber 2 into the first fluid chamber 1, so that the pressure in the test chamber of the second fluid chamber 2 remains substantially constant throughout the test run, and the purity of the environment medium can be maintained.Referring to FIGS. 5A to 6B, the sealing component 30 may include a lower sealing disk 24 below the first disk-shaped separation membrane and an upper sealing disk 23 above the first disk-shaped separation membrane. The lower sealing washer 24 can be fixedly mounted on the load rod 7, for example by welding. Alternatively, the lower sealing disc 24 and the load rod 7 can be manufactured as a single-piece component. The lower seal plate 24, the first disk-shaped separation membrane 5, and the upper seal plate 23 are fixedly mounted by a plurality of fasteners; for example, an annular bolt assembly and a seal plate 25. at least one group of seal plates 28 aand 28 b,which can be clamped between the lower seal plate 24 and the first disk-shaped separation membrane 5, and at least a second group of seal plates 28 aand 28 b,which can be mounted between the upper seal plate 23 and the first disk-shaped separation membrane 5. For example, an inner seal washer 28a may be mounted between the bolt assembly 25 and the load rod 7, and an outer seal washer 28b may be mounted between the bolt assembly 25 and the outer rims 23a and 24a of the upper and lower seal washers 23 and 24. Similar sealing disks may be interposed between the upper and lower sealing disks 23, 24 and the first disk-shaped separation membrane 5. The surfaces of each of the seal disks 23 and 24 adjacent to the surface of the first disk-shaped separation membrane 5 each have a pair of annular grooves (not shown) in which the inner and outer seal disks 28a and 28b are placed. As will be understood by those skilled in the art, a suitable separation membrane can be selected for the test apparatus of the present invention. In selecting a suitable separation membrane, the predetermined pressure requirements of the gas or other fluid used in the test chamber 2 should be taken into account. For example, the first and second disk-shaped separation membranes 5 and 6 may be selected as typical steel separation membranes for high-pressure gas membrane compressors, but is not limited to these. Separation membranes made from non-steel materials may also be suitable. The selection depends on the predetermined pressure requirements, the chemical composition of the fluid in the test chamber 2 and the first fluid chamber 1, as well as other factors.In some embodiments (not shown), the upper sealing washer 23 may also be fixedly mounted on the load rod 7, for example by welding or by making the upper sealing washer 23 and the load rod 7 as a single piece component. The lower seal plate 24 can be fixedly mounted to the first disk-shaped separation membrane 5 and the upper seal plate 23 by a plurality of fasteners 25. With respect to the sealing disk, in some embodiments (not shown), an entire sealing disk may be used to replace the two separate sealing disks 28a and 28b. This sealing disc covers both the part of the surface of the sealing disc 23 or 24 between a plurality of fastening elements 25 and the load rod 7 and the part of the surface of the sealing disc 23 or 24 and the outer edges of the sealing discs 23a, 24a. It should be understood that any configuration of the seal disk that provides sufficient sealing and fluidic complete separation at the interface between the load rod 7, the first disk-shaped separation membrane 5, and the second fluid chamber 2 is included within the scope of the present invention. With respect to the plurality of fasteners 25, although the example of a bolt assembly 25 and the corresponding seal plates is given here as an example of suitable fasteners, it should be understood that any type of fasteners known to those skilled in the art and suitable for fixedly mounting the lower seal plate 24 and the upper seal plate 23 with the load rod 7 and the first plate-shaped separation membrane 5 and for forming a fluid tight seal around the load rod 7 and the membrane 5 are included within the scopes of the present utility model.According to another aspect of the present invention, the test apparatus may further comprise a first connection pipe or conduit 10 connecting the first fluid chamber 1 to the first fluid compensation chamber 3 and a second connection pipe or conduit 11 connecting the second fluid chamber 2 to the second fluid compensation chamber 4. In the embodiments in which the pipes 10, 11 are used, sealing member connection heads 12 are provided at both ends of the first connection pipe 10 and the second connection pipe 11, so that the stability and sealing connection of the first connection pipe 10 and the second connection pipe 11 can be improved in the transportation of lubricating and hydraulic oil between the first fluid chamber 1 and the first fluid balance chamber 3 and in the transportation of hydrogen between the second fluid chamber 2 and the second fluid balance chamber 4. In this embodiment, the test apparatus may further comprise a first fluid inlet pipe 18 connected to the inlet of the first fluid chamber 1 to allow the first fluid (e.g., hydraulic oil or lubricating oil) to be transported into this chamber under a predetermined pressure. Accordingly, a second fluid inlet pipe 19 (e.g., a gas inlet pipe) may be connected to the inlet of the second fluid chamber 2 to transport the second fluid into the second fluid chamber 2 and establish a test environment under the same predetermined pressure. Therefore, when the test chamber is adapted for testing material samples, the predetermined pressure of the second fluid chamber (or test chamber) 2 and its corresponding fluid balancing chamber 4 is equal to the predetermined pressure of the first fluid chamber 1 and its corresponding fluid balancing chamber 3.Moreover, the inspection device may further include a first fluid outlet pipe 20 connected to the outlet of the first fluid compensation chamber 3 to allow the hydraulic oil to be discharged to adjust the pressure and replace it with another fluid as needed. The test apparatus may also include a second fluid outlet pipe 21 connected to the outlet of the second fluid compensation chamber 4, for example, a gas outlet pipe, for adjusting or releasing the pressure in the test environment chamber (i.e., the second fluid chamber 2) as needed. Those skilled in the art can understand that suitable valves can be arranged on each of the inlet and outlet pipes 18, 19, 20 and 21 to effectively control the pressure and volume of the hydraulic oil (or other fluid) supplied to the first fluid chamber 1 and the first fluid balance chamber 3 and also the pressure and volume of the hydrogen (or other fluid) supplied to the second fluid chamber 2 and the second fluid balance chamber 4.According to another aspect of the test apparatus, each of the first fluid chamber 1, the first fluid compensation chamber 3, the second fluid chamber 2 and the second fluid compensation chamber 4 may have a flange 31 protruding outward from the outer wall of the chamber, so that the first fluid chamber 1 may be fixedly mounted to the first separation membrane 5 and the second fluid chamber 2 by a plurality of fastening members, for example, a first bolt assembly having a corresponding seal washer 16 passing through their corresponding flanges 31. Accordingly, the first fluid balancing chamber 3 may fixedly mount the second separation membrane 6 and the second fluid balancing chamber 4 through its respective flanges by another group of multiple fasteners, such as a second bolt assembly with a respective washer 17. The first disk-shaped separation membrane 5 is firmly clamped between the flanges of the first fluid chamber 1 and the second fluid chamber 2, and the second disk-shaped separation membrane 6 is firmly clamped between the flanges of the first fluid compensation chamber 3 and the second fluid compensation chamber 4. This mounting structure promotes the close and stable mounting of the fluid chamber with the corresponding disk-shaped separation membrane. Moreover, this structure facilitates the operation of the material sample support apparatus in the second fluid chamber 2 by disassembling the fluid chamber and its corresponding separation membrane, so that the material sample can be removed or a new material sample can be placed in the second fluid chamber 2 to test the material properties.Referring to FIGS. 1 and 5B, a pair of first separation membrane seals 26 are aligned with the periphery of each surface of the first disk-shaped separation membrane 5 and are clamped between the flanges of the first fluid chamber 1 and the second fluid chamber 2, respectively. Accordingly, a pair of second separation membrane seals 27 are aligned with the periphery of each surface of the second disk-shaped separation membrane 6 and are clamped between the flanges of the first fluid equalizing chamber 3 and the second fluid equalizing chamber 4. These isolation membrane gaskets provide an additional fluid tight seal to each chamber and prevent the leakage of oil, gas or other fluids from each chamber.According to another aspect of the present invention, a support structure 8 is arranged in the second fluid chamber 2 (also referred to here as test chamber) in order to support the material sample 9. In some embodiments, as shown in FIGS. 2 and 3, the support structure 8 may include two separate parallel arms attached and spacedly mounted to the inner surface of the sidewall of the second fluid chamber 2. This structure of the support structure 8 is used for bending tests in which the load rod 7 exerts a force on the center of the material sample 9. The opposite ends of the material sample 9 are supported by the two arms spaced apart from each other of the support structure 8. In some embodiments, the support structure 8 may include two spaced supports on the inner surface of the bottom wall of the second fluid chamber 2. Similar to the support structure in FIGS. 2 and 3, the support structure 8 in FIG. 7 is used for bending tests in which the load bar 7 (not shown) exerts a force on the material sample 9 in the direction of the arrows shown in FIG. 7.In other embodiments, the support structure 8 may be mounted on the inner surface of the bottom wall of the second fluid chamber 2 and includes a sample clamp 32 as shown in FIG. 8. The sample clamp 32 can hold the material sample 9, and the clamp on the load bar 7 (not shown in the figure) can be connected to the other end of the material sample 9 to allow the load bar 7 to apply a compressive or tensile load to the material sample 9. The arrows in Fig. 8 indicate the direction of the compressive and tensile loads.Referring to FIGS. 1 and 8, the test apparatus according to another aspect may include a plurality of support legs 13 located below the second fluid compensation chamber 4 and used to support the test apparatus. A foot pad 15 can be placed under each support foot 13. The foot pads 15 may be made of a material having a high friction coefficient such as rubber to increase the friction force between the test device and the ground, thereby improving the stability of the device. The configuration of the support feet 13 and the foot pads 15 can provide sufficient support to the test fixture and facilitate disassembly and movement to another location. Moreover, one or more connecting rods 14 or 34 may be connected to the bottom of the second fluid chamber 2 to stably mount the bottom of the second fluid chamber to another device. For example, the existing material mechanics testing device may have corresponding connecting devices for connecting to one or more connecting rods 14 and 34 of the testing device, such that the first and second fluid chambers 1 and 2 may be mounted within the supporting construct of the existing material mechanics testing device. In this configuration, the loading device of the existing material mechanics testing device can be connected to the loading rod 7, so that the existing material mechanics testing device is transformed into a testing device that can be used for testing material samples in a pressurized environment.Although the examples of the test apparatus described and shown in this text show that the first fluid chamber 1 and the corresponding first fluid compensation chamber 3 are both situated above the second fluid chamber 2 (forming the test chamber) and the corresponding second fluid compensation chamber 4, it is to be understood that the relative position of these chambers can be realized in different configurations. For example, the second fluid chamber 2 (and the corresponding fluid balance chamber 4) may be respectively located above the first fluid chamber 1 (and the corresponding fluid balance chamber 3), and the load rod 7 enters the first fluid chamber 1 through the bottom wall (or the bottom) of the first fluid chamber 1 and moves in an upward direction toward the second fluid chamber 2 (forming the test chamber). In such an arrangement, the support legs 13 are connected to the underside of the fluid compensation chamber 3 when the fluid compensation chamber 3 is below the fluid compensation chamber 4. As long as the seal ring 22 (through which the load rod 7 is inserted) enters the first fluid chamber 1 (not test chamber) and the seal ring 22 is not connected to the chamber wall of the second fluid chamber (test chamber), all such alternative configurations of the test apparatus should be included within the scope of the contents disclosed in the present utility model.The operating principle of the test device is as follows:It is well known that long term testing of the mechanical properties of materials in a high pressure environment involves at least the following technical challenges: 1) maintaining the required pressure in the test chamber; 2) maintaining the purity of the test environment medium, for example hydrogen, without fouling; 3) accurately measuring the mechanical properties of the sample to be tested. These technical problems are particularly challenging when testing in a high pressure hydrogen environment for a long term, as the relatively small hydrogen molecules are particularly easily leaked and easily contaminated by other substances (e.g., hydraulic oil) leaking into the testing chamber. In the prior art testing devices of the existing art, in order to prevent the leakage of the ambient medium in the test chamber, a very tight seal is normally used between the load rod and the test chamber. However, such too tight a seal may cause a very high frictional force between the movable load bar and the sealing element, leading to inaccurate measurement of the load force applied to the material sample.The inspection apparatus disclosed in the present utility model solves the above technical problems by introducing an inspection environment chamber having a design of double disk-shaped separation membranes and four chambers. The advantage of this device is that this design does not require that the loading rod 7 be passed through a sealing element on any chamber wall or surface of the test chamber, making it possible to isolate the test chamber completely from sources of contamination such as hydraulic oil or lubricating oil. Specifically, the sealing component 30 firmly fixes the stress rod 7 to the separation membrane 5 and seals it against the separation membrane 5 so that the stress rod 7 does not slide relative to the separation membrane 5. Instead, the relative movement of the loading rod 7 to the material sample 9 is realized by the deforming displacement of the disk-shaped separation membrane 5 to which the loading rod 7 is attached. In this way, leakage of the test environment medium (e.g., hydrogen) may be substantially reduced or prevented because the sealing component 30 effectively seals the test chamber 2 with hydrogen.Moreover, the seal ring or the seal member 22 allows the load rod 7 to enter and exit the first fluid chamber 1, which contributes to the sealing of the first fluid chamber 1 and at the same time can significantly reduce the frictional force between the load rod 7 and the seal member 22 by the following mechanism. When the first fluid 1 is a lubricating fluid (e.g., hydraulic oil or lubricating oil), the frictional force acting on the load rod 7 is reduced because the load rod 7 dips into the lubricating fluid contained in the first fluid chamber 1 as it enters and exits the first fluid chamber 1. This reduction in the frictional force on the load bar 7 improves the accuracy of measurement of the load that the load bar 7 transmits to the material sample 9. Moreover, the isolation of hydrogen will avoid the rapid aging of the sealing ring or element 22, which can significantly extend the life of this element, which is particularly important for long term testing.Moreover, the fluid balance chambers 3 and 4 are communicated with their respective fluid chambers 1 and 2 via the fluid lines 10 and 11, making it possible to keep the pressure in each fluid chamber constant. The arrangement of the fluid balancing chambers can maintain the pressure match and equality between the chambers. More specifically, in the embodiments described in the above discussion with reference to Figs. 1-8, the first fluid chamber 1 overlying the second fluid chamber contains only hydraulic lubricating oil. Due to the tight seal between the load rod 7 and the seal ring 22, the macromolecular structure of the hydraulic oil in the first fluid chamber is difficult to leak. At the same time, the frictional force between the hydraulic oil chamber 1 and the load rod 7 under the lubricating action is considerably reduced, which reduces the frictional force when the load rod 7 is moved in the seal ring 22. Since the first disk-shaped separation membrane 5 and the second disk-shaped separation membrane 6 have high flexibility, membrane forces caused by small deformations of the first disk-shaped separation membrane 5 and the second disk-shaped separation membrane 6 can be neglected. Alternatively, in large displacement tests, the membrane force on the first disk-shaped separation membrane 5 and the second disk-shaped separation membrane 6 can be calculated accurately and taken into account in the measurement of the load which the load rod 7 exerts on the material sample. Conveniently, for each combination of the specifically selected membranes 5 and 6, before the mechanical properties of the sample are tested, any additional force exerted on the load rod 7 due to membrane deformation can be tested and determined in advance. In order to improve the measurement accuracy with large displacement, a non-flat membrane may be adopted as the separation membrane, such as a rotationally symmetric corrugated disc membrane.Since the first fluid chamber 1, the high-pressure testing environment chamber 2, the hydraulic oil balancing chamber 3 and the environment testing fluid balancing chamber 4 are all effectively sealed, these chambers can receive high-pressure liquids or gases. Each of the first disk-shaped separation membrane 5 and the second disk-shaped separation membrane 6 may be made of a metallic sheet having high elasticity or other materials having high strength and flexibility suitable for the inspection apparatus disclosed herein. The disk-shaped separation membranes can easily deform when the pressure in the two chambers located on their opposite sides changes and / or the loading rod 7 moves. Since the first fluid freely flows between the first fluid chamber 1 and the first fluid compensation chamber 3 via the first connection line 10 and the hydrogen (or other pressurized fluids) freely flows between the high-pressure test environment chamber 2 and the second fluid compensation chamber 4 via the second connection line 11, the second disk-shaped separation membrane 6 can deform in synchronization with the pressure changes in the first fluid chamber 1 and the high-pressure test environment chamber 2. Therefore, the pressure fluctuations occurring in the first fluid chamber 1 and the high-pressure test environment chamber 2 can be compensated by the corresponding pressure compensation chambers 3 and 4, so that the pressure in the first and second fluid chambers 1 and 2 remains relatively constant. Therefore, the load that the load bar 7 transmits to the material sample 9 can be accurately determined because there is no pressure difference on both sides of the first disk-shaped separation membrane 5 that the load bar does not add an additional load (or only a minimum additional load).The examples of the test apparatus described in the above description are for explaining the operating principle of this test apparatus. However, it should be understood that the novel test apparatus disclosed in the present invention is not limited to the specific examples described herein. Variations of the proposed concepts disclosed herein are also intended to be included within the scope of the present utility model. Moreover, various alterations and modifications can be readily made by those skilled in the art. Therefore, the scope of the present invention is not limited to the specific structures and operations illustrated and described herein. Thus, any changes or alterations in structure or operation made based on the principles and spirit of the present invention are within the scope of the present invention.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedU.S. Pat. No. 8,444,935

[0005]

Claims

An inspection apparatus for inspecting the mechanical properties of material samples in a pressure inspection environment, comprising: a first fluid chamber for receiving a first fluid; a second fluid chamber for receiving a second fluid to provide a pressure inspection environment; a first disk-shaped isolation membrane separating the first fluid chamber from the second fluid chamber and fixedly mounted to the first fluid chamber and the second fluid chamber; a first fluid compensation chamber fluidly connected to the first fluid chamber; a second fluid compensation chamber fluidly connected to the second fluid chamber; a second disk-shaped isolation membrane separating the first fluid compensation chamber from the second fluid compensation chamber and fixedly mounted to the first fluid compensation chamber and the second fluid compensation chamber; a load rod extending through the wall of the first fluid chamber and the first disk-shaped separation membrane to apply a predetermined force to the material sample in the second fluid chamber; a sealing member fixedly connected to the wall of the first fluid chamber to slidably and tightly guide the load rod through the wall of the first fluid chamber; and a sealing component fixedly mounted to the load rod and the first disk-shaped separation membrane to seal the first fluid chamber and the second fluid chamber.The inspection device according to claim 1, wherein the sealing component comprises: a lower sealing disk disposed below the first disk-shaped separation membrane and fixedly, integrally, and seamlessly mounted on the load rod, in particular, manufactured by welding or as a single-piece member; at least one first sealing plate sandwiched between the lower sealing disk and the first disk-shaped separation membrane; an upper sealing disk disposed above the first disk-shaped separation membrane and fixedly mounted with the lower sealing disk and the first disk-shaped separation membrane; and at least one second sealing plate sandwiched between the upper sealing disk and the first disk-shaped separation membrane.The inspection device according to claim 2, wherein the upper disc, the first disc-shaped separation membrane, and the lower disc are fixedly mounted by a plurality of fastening members.The test apparatus of claim 2, wherein each of at least one first sealing plate and at least one second sealing plate forms both an inner sealing plate disposed between the plurality of fasteners and the load rod and an outer sealing plate disposed between the plurality of fasteners and the outer edges of the upper and lower sealing plates.The test apparatus of claim 1, wherein the first fluid is oil and the second fluid is hydrogen.The test apparatus of claim 1, wherein the first fluid chamber, the second fluid chamber, the first fluid compensation chamber, and the second fluid compensation chamber are all cylindrical.The test apparatus of claim 1 further comprising a sample support or connection structure fixedly mounted on the inner surface of the wall of the second fluid chamber.The test apparatus of claim 1 further comprising a first connection pipe fluidly connecting the first fluid chamber to the first fluid compensation chamber and a second connection pipe fluidly connecting the second fluid chamber to the second fluid compensation chamber.The test apparatus according to claim 1, further comprising a first inlet pipe connected to the inlet of the first fluid chamber, and a first outlet pipe connected to the outlet of the first fluid compensation chamber, and a second inlet pipe connected to the inlet of the second fluid chamber, and a second outlet pipe connected to the outlet of the second fluid compensation chamber.The inspection apparatus according to claim 9, wherein each of the first inlet pipe and the first outlet pipe comprises a valve for controlling the flow of the first fluid through the first inlet pipe and the first outlet pipe, and each of the second inlet pipe and the second outlet pipe comprises a valve for controlling the flow of the second fluid through the second inlet pipe and the second outlet pipe.The test apparatus of claim 1, wherein each of the first fluid chamber, the first fluid compensation chamber, the second fluid chamber, and the second fluid compensation chamber has a flange protruding outward from the chamber, such that the first fluid chamber is fixedly mounted to the second fluid chamber by first multi-chamber fasteners guided through the corresponding flanges of the first and second fluid chambers, and the first fluid compensation chamber is fixedly mounted to the second fluid compensation chamber by second multi-chamber fasteners guided through the corresponding flanges of the first and second fluid compensation chambers.The test apparatus of claim 1 further comprising at least one isolation membrane seal clamped between each of the first disk-shaped isolation membrane and the second disk-shaped isolation membrane and the corresponding flange of the first or second fluid chamber or the corresponding flange of the first or second fluid balancing chamber.The test apparatus of claim 1 further comprising a plurality of support feet to stably support at least the second fluid chamber and the second fluid compensation chamber on a surface.The test apparatus according to claim 1 further comprising at least one connecting rod for stably connecting at least the second fluid chamber to a material testing machine.

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