A high temperature and high humidity compression testing machine for composite materials

Abstract

The present application discloses a high-temperature and high-humidity compression tester for composite materials, including a frame as a supporting frame of the tester, at least a test bench and a bracket, the bracket is arranged on the test bench; an environmental chamber is installed above the test bench, and the environmental chamber and the bracket are arranged at an angle between the plane; the environmental chamber has at least two side windows located on both sides of the box body; the video extensometer is located outside the windows on both sides of the environmental chamber, the fixture is arranged in the environmental chamber, and has a locking compression fixture and a combined loading compression fixture, and the light source is arranged outside the environmental chamber. This technical solution adopts a non-contact video extensometer, which will not bring additional load to the sample. The environmental chamber adds two windows on the side so that the video extensometer can see the sample from the front at the same time. The compression fixture is locked after leveling with a ball head to ensure the parallelism requirements of the two pressure plates. The light source bracket is combined with the environmental chamber to adjust the direction of the light source from different angles. A four-column combined loading compression fixture is adopted to make the sample avoid the guide shaft.

Description

Technical Field

[0001] The utility model relates to the field of testing equipment, in particular to a high-temperature and high-humidity compression testing machine special for composite materials. Background Art

[0002] With the development and progress of science and technology, new materials continue to emerge, and performance testing of new materials has become an important means of obtaining new material performance parameters. High-performance fiber composite materials are increasingly used in aerospace, new energy, and ground vehicles. The service environment includes not only room temperature, but also high temperature, wet conditions, and other environments. Compression performance under high temperature and high humidity conditions is a very important test item.

[0003] The existing compression performance tests of composite materials under non-room temperature environments still have the following problems to be solved:

[0004] (1) The working end space of the test sample is small. The commonly used handheld extensometer is not convenient to clamp in a small space, and the clamping direction of the handheld extensometer often has a large deviation, especially in the width direction. In addition, the extensometer is in a high temperature and high humidity environment for a long time, which will also shorten its service life;

[0005] (2) The most common method for measuring modulus in compression tests is strain gauges. However, strain gauges have very high requirements for glue in high humidity environments. Strain gauges are disposable, which will increase costs a lot.

[0006] (3) Non-room temperature environmental tests require the use of an environmental chamber. Conventional high and low temperature environmental chambers only have a window on the front, which cannot accurately observe the degree of change of the sample for tests that monitor the bending degree.

[0007] (4) For the test machine fixture, the parallelism of the ordinary pressure plate must reach 0.02mm, and the processing accuracy requirements are very high. However, the adjustable spherical compression fixture will become more and more biased during the compression test, which will cause risks;

[0008] (5) The standard combined loading compression fixture has only two guide shafts, and the width direction of the specimen will be blocked by the guide shafts, so it is not suitable for video extensometers.

[0009] Therefore, in view of the above defects, it is necessary to improve the existing technology. Utility Model Content

[0010] The utility model aims to overcome at least one defect of the prior art and provide a high temperature and high humidity compression testing machine specially used for composite materials.

[0011] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0012] A high temperature and high humidity compression testing machine for composite materials, comprising:

[0013] A rack, which is a supporting frame of the test machine and has at least a test bench and a bracket, wherein the bracket is arranged on the test bench;

[0014] An environmental box, the environmental box is installed above the test bench, and the environmental box is arranged at an angle with the plane where the bracket is located; the environmental box has at least two side windows located on both sides of the box body;

[0015] A video extensometer, which is mounted on the bracket and located outside the two side windows of the environmental chamber, and is used to track the deformation of the test specimen from the two side windows;

[0016] A fixture, the fixture is arranged in the environmental chamber, and has a locking compression fixture and a combined loading compression fixture, the locking compression fixture has an upper compression fixture and a lower compression fixture, the sides of the upper compression fixture and the lower compression fixture that are arranged opposite to each other are installed on the bracket, the combined loading compression fixture is installed between the sides that are arranged opposite to each other, and the sample to be tested is installed on the combined loading compression fixture;

[0017] A light source is disposed outside the environmental box and irradiates into the environmental box through the side viewing window.

[0018] Furthermore, the bracket has two lead screws, both of which are vertically fixed above the test bench, a crossbeam is arranged between the two lead screws, both ends of the crossbeam are mounted on the lead screws, and the crossbeam is parallel to the test bench, and one end of the clamp is connected to the crossbeam to control the clamp to apply pressure to the sample.

[0019] Furthermore, the video extensometer is installed on the bracket of the testing machine through an adjustment component, and the adjustment component has at least a light bar, which is located outside the lead screw, and connecting plates are provided at both upper and lower ends of the light bar. The light bar is connected to the crossbeam of the bracket through the connecting plates, and an adjustment track is provided on the light bar. The video extensometer is installed on the adjustment track, and the direction of the video extensometer is converted by the adjustment track.

[0020] Furthermore, the adjustment track has three linear guide groups that are perpendicular to each other, and two adjacent linear guide groups are associated and connected, and move linearly along the linear guide groups to which they are associated; wherein the linear guide group connected to the optical bar has an annular buckle portion, and the linear guide group can be connected to the optical bar through the annular buckle portion and rotate around the optical bar.

[0021] Furthermore, the connecting plate is an L-shaped plate, one end of which is nested outside the light bar and can rotate around the light bar, and the other end of the L-shaped plate can be rotated to the crossbeam and connected to the crossbeam.

[0022] Furthermore, the environmental chamber also has a front viewing window and a fixture port, wherein the front viewing window is located at the front end of the environmental chamber, and a three-window environmental chamber structure is formed by the two side viewing windows and the front viewing window; the fixture port is arranged on the upper and lower sides of the environmental chamber body, and the fixture is arranged in the body of the environmental chamber through the fixture port.

[0023] Further, the upper compression fixture of the locking compression fixture has a connecting rod, a spherical assembly and an upper pressure plate, one end of the connecting rod passes through the upper fixture port of the environmental box and is connected to the crossbeam, the spherical assembly and the upper pressure plate are sequentially sleeved on the connecting rod, and the parallelism of the upper pressure plate and the lower pressure plate is adjusted by the spherical assembly;

[0024] The lower compression fixture of the locking compression fixture has a lower pressure plate, and the combined loading compression fixture is installed on the lower pressure plate.

[0025] Furthermore, the combined loading and compression fixture has two sets of upper and lower clamp bodies, the test sample is installed between the clamp bodies, and the contact surfaces of the test sample and the upper and lower sets of clamp bodies are guaranteed to be in the same plane. The clamp bodies have four sets of guide shafts to prevent the viewing angle of the video extensometer from being blocked by the guide shafts during testing.

[0026] Furthermore, a support rod is provided on one side of the box body of the environmental box where the side viewing window is provided, the support rod is rotatably connected to a cross bar, a slide groove is provided on the cross bar, one end of the light source is installed on the slide groove of the cross bar, and the direction of the light source can be adjusted according to the cross bar.

[0027] Furthermore, the testing machine also has a water leakage prevention device, which includes a sealing block and a water receiving tray. The sealing block is installed at the clamp port on the upper side of the environmental box to prevent water vapor from escaping along the upper gap of the environmental box, causing the heating and humidification speed to be too slow; the water receiving tray is arranged at the connecting rod on the lower side of the environmental box body to prevent the water droplets condensed inside the environmental box from flowing out of the box along the clamp connecting rod. A water pipe joint is arranged on the water receiving tray, and the water pipe joint is connected to an external hose to introduce the water vapor generated in the environmental box into the water storage barrel through the hose.

[0028] Based on the above-mentioned high temperature and high humidity compression testing machine for composite materials, it has the following beneficial effects:

[0029] (1) This technical solution is different from the conventional environmental chamber with only a front window. Side windows are provided on both sides, so that the deformation process of the sample can be observed on both sides of the sample;

[0030] (2) This technical solution uses a dual-video extensometer to measure and track the deformation on both sides. Compared with the use of a contact extensometer, the application of a dual-video extensometer greatly improves the efficiency of the test and greatly reduces the difficulty of operation. It can measure the strain of the sample during the entire test without contacting the sample, has good repeatability, is not affected by the operator's operating techniques, and has an almost unlimited service life. It does not have the problem of being damaged by a broken sample like an ordinary extensometer. It can safely track the sample until it breaks, and will not bring additional load to the sample, especially for soft samples, and will not be damaged by the knife edge.

[0031] (3) When the test machine of the technical solution adopts the existing universal testing machine, the environmental chamber is tilted at a certain angle relative to the testing machine, and the video extensometers arranged on both sides are also tilted at a certain angle, so that the sample in the environmental chamber can be illuminated, thereby completing the deformation tracking, and effectively solving the problem of the testing machine column blocking the left and right side windows;

[0032] (4) The video extensometer bracket of the testing machine of this technical solution is composed of multiple matching linear guide rails to effectively adjust the position;

[0033] (5) The locking compression fixture of the testing machine of this technical solution is a locking compression fixture after the ball head is leveled. The spherical pressure plate is locked under the full load force condition to ensure the parallelism requirements of the two pressure plates, and the spherical surface will not tilt due to the tilt of the sample;

[0034] (6) The test machine of this technical solution combines the light source bracket with the environmental chamber, and the direction of the light source can be adjusted from different angles;

[0035] (7) The fixture of the testing machine of this technical solution adopts a four-column combined loading and compression fixture to make the sample avoid the guide shaft;

[0036] (8) The test machine of the present technical solution is provided with a water-leakage prevention device, which effectively prevents the influence of water vapor on the electrical system of the test machine and the test specimen, thereby ensuring the stability of the test and the service life of electrical equipment such as the environmental chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 Schematic diagram of the structure of the testing machine in this embodiment;

[0038] Figure 2 yes Figure 1 Schematic diagram of the structure from top view;

[0039] Figure 3 It is a schematic diagram of the installation structure of the video extensometer of this embodiment;

[0040] Figure 4 Schematic diagram of the structure of the environmental chamber of this embodiment;

[0041] Figure 5 is a schematic diagram of the light source installation structure of this embodiment;

[0042] Figure 6 is a schematic diagram of the locking and compression clamp structure of this embodiment;

[0043] Figure 7 This is a schematic diagram of the structure of the combined loading and compression fixture holding a specimen in this embodiment;

[0044] Figure 8-Figure 9 Schematic diagram of the water leakage prevention structure of this embodiment;

[0045] In the figure:

[0046] 1- Testing machine;

[0047] 10-frame, 100-bracket, 1000-screw, 1001-column, 1002-protective cover, 1003-light bar, 1004-connecting plate, 1005-X-axis guide rail, 1006-Y-axis guide rail, 10060-annular buckle part, 1007-Z-axis guide rail, 101-test bench;

[0048] 11-environmental chamber, 111-front window, 112-side window, 113-chamber door, 114-fixture port;

[0049] 12- Video extensometer;

[0050] 13-light source, 130-support rod, 1300-protrusion, 131-cross bar, 1310-slide groove;

[0051] 140-locking compression fixture, 1400-connecting rod, 1401-spherical assembly, 1402-upper pressure plate, 1403-locking nut, 1404-lower pressure plate, 141-combined loading compression fixture, 1410-clamp body, 1411-guide shaft, 1412-shaft hole, 1413-adjusting shaft;

[0052] 150-sealing block, 151-water tray, 152-water pipe joint;

[0053] 2- Specimen. DETAILED DESCRIPTION

[0054] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0055] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0057] In the description of this embodiment, the terms "upper", "lower", "right", and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present utility model.

[0058] A high temperature and high humidity compression testing machine for composite materials according to this embodiment includes:

[0059] The rack is the supporting frame of the test machine, and at least has a test bench and a bracket, and the bracket is arranged on the test bench;

[0060] An environmental chamber, the environmental chamber is installed above the test bench, and the environmental chamber is set at an angle with the plane where the bracket is located; the environmental chamber has at least two side windows located on both sides of the chamber;

[0061] Video extensometer: The video extensometer is installed on a bracket and located outside the windows on both sides of the environmental chamber. It is used to track the deformation of the test specimen from the windows on both sides.

[0062] A fixture is arranged in the environmental chamber, and has a locking compression fixture and a combined loading compression fixture. The locking compression fixture has an upper compression fixture and a lower compression fixture. The sides of the upper compression fixture and the lower compression fixture that are arranged opposite to each other are installed on the bracket, and the combined loading compression fixture is installed between the sides that are arranged opposite to each other. The sample to be tested is installed on the combined loading compression fixture.

[0063] The light source is arranged outside the environmental chamber, and the light source shines into the environmental chamber through a side window.

[0064] The following is combined with Figure 1-9 , the high temperature and high humidity compression testing machine specially used for composite materials of the utility model is specifically described.

[0065] The frame 10 of this embodiment as the supporting frame of the test machine 1 is basically the same as the frame structure of the existing test machine. Figure 1-Figure 2 As shown, they all have a test bench 101 and a bracket 100. Since the test equipment is carried on them, a high-rigidity loading frame is adopted to ensure the smoothness of the test operation and the displacement accuracy of the test equipment. The test bench 101 is a cubic structure, and has a power drive mechanism such as a cylinder and a piston inside. The test bench 101 can adopt the existing test bench structure, which will not be described in detail here. The test equipment is installed on the upper surface of the test bench 101, and the bracket 100 is also installed on the test bench 101.

[0066] The bracket 100 is a supporting structure of the test equipment, which has a vertical supporting structure and a lateral supporting structure. The vertical supporting structures are arranged on both sides above the test bench 101, and the lateral supporting structure is arranged between the vertical supporting structures on both sides, and the two ends are connected to the vertical supporting structures and can move vertically along the vertical supporting structures.

[0067] More specifically, the vertical support structure has a column 1001 as a support body of the vertical support structure, and screws 1000 are arranged on two opposite sides of the column 1001. There are two screws 1000, which are vertically fixed above the test bench. The outer covers of the screws 1000 and the columns 1001 are provided with protective covers 1002. The protective cover 1002 is an arc-shaped structure, which is completely placed on the outside of the column 1001. The screws 1000 are located between the two side walls of the arc of the protective cover 1002; the transverse support structure is a beam (not shown in the drawings), and both ends of the beam are installed on the screws 1000 on both sides and can move up and down along the screws 1000. The beam is parallel to the table top of the test bench 101, and the locking and compression clamp of the testing machine 1 is installed on the beam. The locking and compression clamp is controlled by the movement of the beam to apply test pressure to the sample 2.

[0068] Combination Figure 3As shown, a light bar 1003 is vertically arranged on the outside of each protective cover 1002, and connecting plates 1004 are arranged at the upper and lower ends of the light bar 1003. The light bar 1003 is connected to the crossbeam through the connecting plates 1004. The connecting plate 1004 of this embodiment is an L-shaped plate, one end of the L-shaped plate is nested on the outside of the light bar 1003 and can rotate around the light bar 1003, and the other end can be rotated to the crossbeam and connected to the crossbeam; between the upper and lower connecting plates 1004 A guide rail assembly is fixed on the optical bar 1003 between the two ends of the optical bar 1003, and the guide rail assembly has three linear guide rails, namely, an X-axis guide rail 1005, a Y-axis guide rail 1006 and a Z-axis guide rail 1007, wherein the Y-axis guide rail 1006 is fixed on the optical bar 1003, and its extension direction is consistent with the extension direction of the optical bar 1003, and the guide rail seat of the Y-axis guide rail 1006 and the part fixed to the optical bar 1003 have an annular buckle portion 10060, and the Y-axis guide rail 100 6 can be connected to the optical bar 1003 through the annular buckle portion 10060 and rotate around the optical bar 1003; an X-axis guide rail 1005 is fixed on the track of the Y-axis guide rail 1006, the extension direction of the X-axis guide rail 1005 is perpendicular to the Y-axis guide rail 1006, parallel to the table of the test bench 101, and can move along the extension direction of the Y-axis guide rail 1006; a Z-axis guide rail 1007 is fixed on the track of the X-axis guide rail 1005, the extension direction of the Z-axis guide rail 1007 is perpendicular to the X-axis, parallel to the table of the test bench 101, and can move along the extension direction of the X-axis guide rail 1005; a video extensometer 12 is fixed on the track of the Z-axis guide rail 1007, and the video extensometer 12 can move along the extension direction of the Z-axis guide rail 1007. Through the aforementioned guide rail assembly, the video extensometer 12 of this embodiment can realize rotation or movement at any angle and direction to observe the sample 2 during the experiment.

[0069] The video extensometer 12 of this embodiment adopts a high-precision non-contact video extensometer, a telecentric lens with a field of view of 25mm, a measurement accuracy better than 0.2 microns, and adopts dual lenses for front and back side measurements, so as to monitor the curvature of the sample 2. The bracket of the video extensometer 12 is made of aluminum profile and is installed on the outside of the two side windows of the environmental chamber 11, and the angle and distance movement are realized by the guide rail assembly.

[0070] Combination Figure 4As shown, the environmental box 11 of this embodiment is a high temperature and high humidity environmental box, which complies with the technical conditions of GB10589-89 low temperature test box, GB10592-89 high and low temperature test box, and GB10586-89 wet heat test box. Under the condition that the device driving capability permits, the user can freely combine various temperature and humidity curves. The structure of the high temperature and high humidity environmental box is roughly the same as that of the existing high temperature and high humidity environmental box, and has a body, and the body has an outer shell. The outer shell is usually made of high-quality steel plate or stainless steel material, and has good strength and corrosion resistance. The surface of the outer shell is sprayed with anti-rust paint and decorative coating to effectively protect the box from erosion by the external environment; the inner box is provided in the outer shell, and the inner box is the core part of the high and low temperature environmental box, which is in direct contact with the test sample. It is usually made of metal materials such as stainless steel or aluminum alloy, and has good thermal conductivity and corrosion resistance. In order to ensure the stability of the internal temperature of the environmental box and the energy-saving effect, high-efficiency thermal insulation materials, such as polyurethane foam materials, are filled between the inner box and the outer shell to reduce heat transfer and improve the energy efficiency ratio of the equipment. The shell is also equipped with a refrigeration system and a heating system. The refrigeration system is the key to the low temperature environment of the environmental box. It is mainly composed of components such as a compressor, a condenser, an expansion valve and an evaporator. Through the circulation of refrigerant in the system, the rapid cooling and temperature control inside the environmental box are realized; the heating system is responsible for providing a high temperature environment. It is usually composed of components such as electric heating elements, thermostats and temperature sensors. The electric heating elements are heated according to the instructions of the thermostat to make the internal temperature of the environmental box reach the set value; in addition, a control system is set on the shell to be responsible for the operation monitoring and parameter setting of the entire equipment. The control system is usually equipped with a microcomputer controller or a touch screen human-machine interface, which can easily perform temperature setting, time setting, curve recording and other operations. At the same time, the control system also has a variety of protection functions, such as overload protection, over-temperature protection, etc., to ensure the safe operation of the equipment. In order to ensure the uniformity and stability of the temperature inside the environmental box, it is usually equipped with an air circulation system. The system is mainly composed of components such as fans, air ducts and guide plates, and the uniform distribution of air and heat transfer inside the box are achieved through forced convection. The above results are the basic structure of the existing environmental chamber, which is the same as the environmental chamber of the present technical solution. Due to the prior art, no further detailed description is given here.

[0071] The difference between the environmental chamber 11 of the present technical solution and the existing environmental chamber is that the existing environmental chamber is usually only provided with a front window, while the environmental chamber 11 of the present solution is provided with a left window 112 and a right window 112 on at least the left and right sides in addition to the front window 111. Specifically, the environmental chamber 11 has a chamber door 113, one side of the chamber door 113 is connected to the body of the environmental chamber 11, and the other side can be opened and closed. The sample 2 is installed into the environmental chamber 11 through the chamber door 113 for testing; a front window 111 is provided on the chamber door 113, and a left window 112 and a right window 112 are provided on the body on both sides of the chamber door 113 to form an environmental chamber structure with three windows.

[0072] In addition, another difference between the environmental chamber 11 of the present solution and the existing environmental chamber is that the environmental chamber 11 of the present solution forms a certain angle α with the plane A where the bracket 100 of the testing machine 1 is located. More specifically, the part of the environmental chamber 11 for testing goes deep into the two lead screws 1000 and the crossbeam of the bracket 100. Since the video extensometer 12 is located outside the bracket 100, and the two video extensometers 12 are always located on the same straight line L as the sample 2, and the sample 2 is always located on the plane A where the bracket 100 is located, in order to avoid the position of the two lead screws 1000 and the column 1001 of the bracket 100 affecting the observation field of the video extensometer 12, the part of the environmental chamber 11 that goes deep into the bracket 100 forms a certain angle α with the plane A where the bracket 100 is located. The relationship between the angle α and the angle β between the straight line L where the video extensometer 12 is located and the plane A where the bracket 100 is located is: α+β=90°.

[0073] Again, another difference between the environmental chamber 11 of the present scheme and the existing environmental chamber is that the environmental chamber 11 of the present scheme is also provided with a clamp port 114 on the main body, and the clamp port 114 is located on the top cover of the main body. According to the clamping requirements of the sample 2 in the actual test, the clamp port 114 can be set alone on the top of the environmental chamber 11, or can be set at the top and bottom of the environmental chamber 11 at the same time. The clamp device of the testing machine 1 penetrates into the environmental chamber 11 from the clamp port 114 to clamp the sample 2 for testing. When performing the compression test, the video extensometer 12 can directly observe the marking points on the front and back sides of the sample 2 through the left window 112 and the right window 112.

[0074] Combination Figure 5As shown, a support rod 130 is provided on the box body on either side of the left window 111 and / or the right window 112 on the environmental box 11, and a protrusion 1300 is provided on the support rod 130. The protrusion 1300 is a U-shaped groove structure, and a cross bar 131 is connected in the groove of the U-shaped groove structure. The cross bar 131 and the protrusion 1300 are connected by pins. The cross bar 131 can be rotated by an angle using the pin as a connecting fulcrum. A slide groove 1310 is provided on the cross bar 131, and one end of the light source 13 is installed on the slide groove 1310 of the cross bar 131, and can move according to the extension direction of the slide groove 1310. The light source 13 is directly connected to the environmental box 11 through the support rod 130 and the cross bar 131, and the light source angle required for the test can be adjusted within a limited test space.

[0075] It should be noted that the three windows of the environmental box 11 are all made of optical glass with high light transmittance, and the optical glass adopts a three-layer structure to ensure good thermal insulation performance.

[0076] Combination Figure 6 As shown in the figure, it is a locking compression fixture 140 for applying test pressure to the sample 2 during the compression test of this embodiment. The locking compression fixture 140 is a special spherical leveling locking compression fixture. The locking compression fixture 140 has an upper compression fixture and a lower compression fixture, wherein the upper compression fixture has a connecting rod 1400, one end of the connecting rod 1400 passes through the upper fixture port 114 of the environmental box 11 and is connected to the crossbeam, the spherical component 1401 and the upper pressure plate 1402 are located in the environmental box 11, and are sequentially sleeved on the connecting rod 1400 from top to bottom, and the spherical component 1401 and the upper pressure plate 1402 are connected to each other. A locking screw 1403 is arranged between the upper and lower compression clamps of the locking and compression clamp 140. The lower compression clamp of the locking and compression clamp 140 has a lower pressure plate 1404. Since the composite material compression test has very high requirements on the parallelism and flatness of the upper and lower pressure plates of the test, the spherical component 1401 of the locking and compression clamp 140 is designed as an upper spherical structure. The parallelism of the upper pressure plate 1402 and the lower pressure plate 1404 is adjusted by the spherical surface. The locking screw 1403 of the upper spherical structure and the upper pressure plate 1402 is locked under the maximum force of the test machine 1. As long as the test load is not greater than the maximum force of the test machine 1, the flatness of the lower pressure plate 1404 will not change. Since the locking and compression clamp 140 needs to be used in the environmental chamber 11, the locking and compression clamp 140 is connected to the test machine 1 through a large-diameter connecting rod 1400 to increase the contact area between the upper pressure plate 1402 and the connecting rod 1400.

[0077] Combination Figure 7As shown, the combined loading compression fixture 141 for clamping the specimen 2 during the compression test of this embodiment is provided. The combined loading compression fixture 141 has two sets of clamping bodies 1410, upper and lower. As shown in the figure, there are four clamping bodies 1410, and the four clamping bodies 1410 are arranged in a "field" shape. The two clamping bodies 1410 located above are a set of upper clamping bodies, and the two clamping bodies 1410 located below are another set of lower clamping bodies. There is an adjustment shaft 1413 between the two clamping bodies of each set of clamping bodies 1410 to facilitate clamping the specimen 2 to be tested, ensuring that the specimen 2 under pressure is longitudinally arranged between the upper and lower sets of clamping bodies 1410. There is a controllable pressure gap between the upper and lower sets of clamping bodies 1410, and the contact surfaces of the specimen 2 to be tested with the upper and lower sets of clamping bodies 1410 are guaranteed to be in one plane. Each clamping body 1410 has two shaft holes 1412, and four guiding shafts 1411 are贯通设置 (penetratingly arranged) through the shaft holes of the upper and lower sets of clamping bodies 1410 to prevent the viewing angle of the video extensometer 12 from being blocked by the guiding shafts 1411 during the test.

[0078] Since this compression test is carried out in a high-humidity environment, water droplets will condense inside the fixture, the specimen 2, and the environmental chamber 11. The water droplets flow along the fixture connecting rod 1400 to the outside of the environmental chamber 11 of the testing machine 1, which may damage the electrical system of the testing machine 1. Combining Figure 8 and Fig. 9 As shown, the testing machine 1 also has a water leakage prevention device. The water leakage prevention device includes a sealing block 150 and a water receiving tray 151. The sealing block 150 is installed at the fixture port 114 on the upper side of the environmental chamber 11 to prevent water vapor from running out through the upper gap of the environmental chamber 11, resulting in too slow heating and humidification speed; the water receiving tray 151 is arranged at the lower connecting rod 1400 under the lower side of the environmental chamber 11 body. The flowing water droplets flow into the water receiving tray 151 to prevent the water droplets condensed inside the environmental chamber 11 from flowing along the fixture connecting rod 1400 to the outside of the environmental chamber 11. A water pipe joint 152 is arranged on the water receiving tray 151, and the water pipe joint 152 is connected to an external hose to introduce the water vapor generated inside the environmental chamber 11 into the water storage bucket through the hose.

[0079] Based on the above structure of the testing machine, the process of the compression test of this embodiment is as follows:

[0080] ① Install the environmental chamber: Install the multi-window environmental chamber 11 on the test bench 101 of the testing machine 1 through the high and low temperature chamber rack. The environmental chamber 11 forms an angle α with the testing machine 1 to ensure that the front and rear video extensometers 12 can capture the inside of the box through the left window 111 and the right window 112. Adjust the height of the high and low temperature chamber rack and connect the liquid level sensor, water inlet, drain outlet and other internal mechanisms of the testing machine 2 according to the water pipe markings;

[0081] ②Install the connecting rod and the anti-leakage device: install the upper and lower connecting rods 1400, put the sealing block 150 and the water receiving tray 151 of the anti-leakage device on the upper and lower tie rods 1400, adjust the position to avoid the upper and lower parts of the environmental box 11 to prevent the position interference when the environmental box 11 is pushed in, and press the sealing block 150;

[0082] ③ Fixture leveling: Install the locking compression fixture 140 on the upper and lower tie rods 1400, loosen but not completely loosen the four locking screws 1403 on the spherical assembly 1401, open the testing machine 2, move the crossbeam, and press the upper pressure plate 1402 and the lower pressure plate 1404 to the maximum load of the testing machine 100kN through software control, and tighten the four locking screws 1403 diagonally with the same torque to complete the pressure plate leveling, unload, and separate the upper pressure plate 1402 and the lower pressure plate 1404 to a distance greater than 140mm;

[0083] ④ Sealing: Push the multi-window environmental box 11 into the testing machine 2, plug the connection with the connecting rod 1400 with insulation cotton, insert the upper and lower baffles, and press the anti-leakage device of the upper connecting rod 1400 against the upper surface of the environmental box 11;

[0084] ⑤ Mark the specimen: mark the working section of specimen 2 that meets the ASTM D6641 standard. Use a marker pen and white paint to make two marking points on specimen 2 with a spacing of 6-8mm and a diameter of 1-2mm, and let it dry;

[0085] ⑥ Install the sample: install the marked sample 2 into the four-column combined loading and compression fixture 141. During installation, ensure that the end face of the sample 2 is flush with the end face of the fixture body 1410. Tighten the eight screws on the side to 3-4.5Nm with a torque wrench. Place the installed sample and the combined loading and compression fixture assembly on the lower pressure plate 1404 according to the scale on the pressure plate.

[0086] ⑦ Adjust the video extensometer and light source: install the telecentric lens video extensometer 12 with a 25mm field of view in front and behind, and adjust the height and direction of the video extensometer 12; install the light source 13 and the light source support rod 130, and adjust the direction of the light source. The final adjustment result is that the color distinction between the mark point on the sample 2 and the sample 2 itself is the largest, and the image is the clearest;

[0087] ⑧ Compression force test: move the crossbeam, the upper pressure plate 1402 is close to the upper end surface of the combined loading compression fixture 141, close the door 113 of the environmental box 11, set the temperature of the environmental box 11 to 80°C and the humidity to 50%, wait until the temperature and humidity reach the target value, keep for 15-20 minutes, click start on the software, and run the test;

[0088] ⑨Test completion: The video extensometer 12 captures the deformation process of the sample 2 and transmits it to the control system to generate a deformation curve.

[0089] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For those skilled in the art, various obvious changes, readjustments and substitutions can be made without departing from the scope of protection of the present invention. It is not necessary and impossible to list all implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims

1. A high temperature and high humidity compression testing machine for composite materials, characterized in that: include: A rack, which is a supporting frame of the test machine and has at least a test bench and a bracket, wherein the bracket is arranged on the test bench; An environmental box, the environmental box is installed above the test bench, and the environmental box is arranged at an angle with the plane where the bracket is located; the environmental box has at least two side windows located on both sides of the box body; A video extensometer, which is mounted on the bracket and located outside the two side windows of the environmental chamber, and is used to track the deformation of the test specimen from the two side windows; A fixture, the fixture is arranged in the environmental chamber, and has a locking compression fixture and a combined loading compression fixture, the locking compression fixture has an upper compression fixture and a lower compression fixture, the sides of the upper compression fixture and the lower compression fixture that are arranged opposite to each other are installed on the bracket, the combined loading compression fixture is installed between the sides that are arranged opposite to each other, and the sample to be tested is installed on the combined loading compression fixture; A light source is disposed outside the environmental box and irradiates into the environmental box through the side viewing window.

2. The high temperature and high humidity compression testing machine for composite materials according to claim 1, characterized in that: The bracket has two lead screws, both of which are vertically fixed above the test bench. A crossbeam is arranged between the two lead screws, and both ends of the crossbeam are mounted on the lead screws. The crossbeam is parallel to the test bench. One end of the clamp is connected to the crossbeam to control the clamp to apply pressure to the sample.

3. The high temperature and high humidity compression testing machine for composite materials according to claim 2, characterized in that: The video extensometer is installed on the bracket of the testing machine through an adjustment component. The adjustment component has at least a light bar, and the light bar is located outside the lead screw. Connecting plates are provided at both upper and lower ends of the light bar. The light bar is connected to the crossbeam of the bracket through the connecting plates. An adjustment track is provided on the light bar, and the video extensometer is installed on the adjustment track. The direction of the video extensometer is converted through the adjustment track.

4. The high temperature and high humidity compression testing machine for composite materials according to claim 3, characterized in that: The adjustment track has three linear guide groups that are perpendicular to each other, and two adjacent linear guide groups are associated and connected, and move linearly along the linear guide groups they are associated with; wherein the linear guide group connected to the optical bar has an annular buckle portion, and the linear guide group can be connected to the optical bar through the annular buckle portion and rotate around the optical bar.

5. The high temperature and high humidity compression testing machine for composite materials according to claim 3, characterized in that: The connecting plate is an L-shaped plate, one end of which is embedded in the outer side of the light bar and can rotate around the light bar, and the other end of which can rotate to the crossbeam and be connected to the crossbeam.

6. The high temperature and high humidity compression testing machine for composite materials according to claim 2, characterized in that: The environmental chamber also has a front viewing window and a fixture port, wherein the front viewing window is located at the front end of the environmental chamber, and a three-window environmental chamber structure is formed by two side viewing windows and one front viewing window; the fixture port is arranged on the upper and lower sides of the environmental chamber body, and the fixture is arranged in the body of the environmental chamber through the fixture port.

7. The high temperature and high humidity compression testing machine for composite materials according to claim 6, characterized in that: The upper compression clamp of the locking compression clamp has a connecting rod, a spherical assembly and an upper pressure plate; the lower compression clamp of the locking compression clamp has a lower pressure plate, and the combined loading compression clamp is installed on the lower pressure plate; one end of the connecting rod passes through the upper clamp port of the environmental chamber and is connected to the crossbeam, the spherical assembly and the upper pressure plate are sequentially mounted on the connecting rod, and the parallelism of the upper pressure plate and the lower pressure plate is adjusted by the spherical assembly.

8. The high temperature and high humidity compression testing machine for composite materials according to claim 1, characterized in that: The combined loading and compression fixture has two sets of upper and lower clamp bodies, the sample to be tested is installed between the clamp bodies, and the contact surfaces of the sample to be tested and the upper and lower clamp bodies are guaranteed to be in the same plane. The clamp bodies are provided with four sets of guide shafts to prevent the viewing angle of the video extensometer from being blocked by the guide shafts during testing.

9. The high temperature and high humidity compression testing machine for composite materials according to claim 1, characterized in that: A support rod is provided on one side of the environmental box where the side window is provided. The support rod is rotatably connected to a cross bar, a slide groove is provided on the cross bar, one end of the light source is installed on the slide groove of the cross bar, and the direction of the light source can be adjusted according to the cross bar.

10. The high temperature and high humidity compression testing machine for composite materials according to claim 6, characterized in that: The testing machine also has a water leakage prevention device, which includes a sealing block and a water receiving tray. The sealing block is installed at the clamp port on the upper side of the environmental box; the water receiving tray is arranged at the connecting rod on the lower side of the environmental box body, and a water pipe joint is arranged on the water receiving tray. The water pipe joint is connected to an external hose to introduce the water vapor generated in the environmental box into the water storage barrel through the hose.

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