Biaxial tensile fatigue experiment device suitable for maritime work materials and using method thereof

Abstract

The invention provides a biaxial tensile fatigue experiment device suitable for maritime work materials and a use method of the biaxial tensile fatigue experiment device. The biaxial tensile fatigue experiment device comprises a main clamping assembly, an auxiliary clamping assembly, a connecting rod and a workbench, the main clamping assembly and the auxiliary clamping assembly are connected with the tensile sample; the number of the main clamping assemblies and the number of the auxiliary clamping assemblies are both two, the two ends of the two auxiliary clamping assemblies are connected with one ends of the connecting rods correspondingly, and the other ends of the connecting rods are movably connected with one ends of the two main clamping assemblies correspondingly. The other ends of the two main clamping assemblies are respectively connected with the workbench and the fatigue testing machine; according to the biaxial tensile fatigue experiment device suitable for the maritime work material and the use method of the biaxial tensile fatigue experiment device, on the basis that the structure of the device is simplified and the cost of the device is reduced, the load ratio on the two shafts can be adjusted at will, and the diversity and flexibility of loading forms are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of marine engineering material performance detection technology, and in particular to a mechanical biaxial tensile fatigue test device with variable loading ratio suitable for marine engineering materials and a method of using the same. Background Art

[0002] There are a large number of engineering structures in the field of marine engineering. These engineering structures are often subjected to multiaxial stress, so it is necessary to carry out multiaxial fatigue tests on materials. Multiaxial fatigue has many types, such as biaxial tension, biaxial tension-torsion, biaxial bending-torsion, and biaxial tension-bending. Among them, the biaxial tension test combined with the cross-shaped specimen can simulate a variety of stress states and is currently the most commonly used multiaxial fatigue test method.

[0003] At present, the technical routes adopted by the biaxial tensile test are mainly divided into two types: mechanical and electronic hydraulic. The electronic hydraulic test generally uses four loading units to directly perform biaxial tensile loading on the sample. For example, Chinese patent CN1865910A installs four electro-hydraulic servo testing machines on the main frame to realize direct hydraulic drive of the bidirectional stress field; Chinese patent CN206177714U discloses a method in which four screw modules are arranged crosswise in the same plane, and the screw modules are driven by four servo motors to realize biaxial loading of the cross sample; Chinese patent CN221174182U designs a method in which four loading units are installed around the test kettle to realize in-situ biaxial loading in a lead-bismuth environment; Chinese patent CN107703003A develops an ultra-high temperature in-situ biaxial tensile compression fatigue test platform composed of four electric testing machines combined with a high-frequency heating system, which can realize high-temperature biaxial loading of the cross sample; Chinese patent CN116754376A designs a biaxial compression test equipment composed of four testing machines, which can realize biaxial creep testing of the sample.

[0004] The mechanical type generally consists of a loading unit combined with a mechanical structure to achieve biaxial loading of the specimen. For example, the loading device designed in Chinese patent CN105571942A includes a frame, a slider and a guide rail, which can achieve biaxial tension-tension and biaxial compression-compression loading of the specimen in combination with a uniaxial fatigue testing machine; Chinese patent CN106644720A discloses a biaxial loading device for a uniaxial fatigue testing machine composed of a downward pressure prism, four diagonal braces and a workbench, which realizes biaxial tension-tension loading with a variable stress-strain ratio for a cross-shaped specimen; Chinese patent CN107941598A discloses a square frame structure, and the fatigue testing machine applies a load at one end of the frame, which can achieve biaxial tension-compression loading of the test piece placed in the frame; Chinese patent CN206556989U designs an octahedral frame structure, in which the cross specimen is connected to four guide rails, and biaxial tension-tension and biaxial compression-compression loading of the specimen is achieved through a uniaxial testing machine.

[0005] Of the two test methods for biaxial tensile testing mentioned above, the electronic hydraulic method has the advantages of flexible loading and the load ratio of the two axes can be adjusted at will, but the equipment construction, use, and maintenance costs are high, and the structure is complex; although the mechanical method has a simple structure and low cost, the load ratio on the two axes is often immutable, and the loading form is relatively single. Therefore, it is of great significance to study how to achieve the load ratio on the two axes that can be adjusted at will on the basis of simplifying the device structure. Summary of the invention

[0006] In view of this, the present invention aims to propose a biaxial tensile fatigue test device suitable for marine engineering materials and a method of using the same, so as to solve the problem that the biaxial tensile test device in the prior art cannot simultaneously satisfy the requirement of freely adjusting the load ratio on the two axes on the basis of simplifying the device structure; thereby achieving the requirement of freely adjusting the load ratio on the two axes on the basis of simplifying the device structure and reducing the cost of the device, thereby improving the diversity and flexibility of the loading forms.

[0007] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0008] The present invention relates to a biaxial tensile fatigue test device applicable to marine engineering materials and a method for using the same. The biaxial tensile fatigue test device applicable to marine engineering materials comprises a main clamping assembly, a secondary clamping assembly, a connecting rod and a workbench; the main clamping assembly and the secondary clamping assembly are both connected to the tensile test specimen; two main clamping assemblies and two secondary clamping assemblies are each provided, the two ends of the two secondary clamping assemblies are respectively connected to one end of the connecting rod, and the other end of the connecting rod is respectively connected to one end of the two main clamping assemblies in a movable manner; the other ends of the two main clamping assemblies are respectively connected to the workbench and the fatigue testing machine.

[0009] Furthermore, the tensile specimen is connected to the main clamping assembly and the auxiliary clamping assembly through pins respectively.

[0010] Furthermore, the tensile specimen includes specimen part one, specimen part two and specimen part three, specimen part one is connected to specimen part three through specimen part two, and specimen part three is respectively connected to the main clamping assembly and the auxiliary clamping assembly.

[0011] Furthermore, the thickness L1 of the first sample portion ≤ the thickness L2 of the second sample portion ≤ the thickness L3 of the third sample portion.

[0012] Furthermore, the main clamping assembly includes a main clamp, a main body and a connecting shaft; one end of the main body is connected to the tensile specimen through the main clamp, and the other end of the main body is connected to a workbench or a fatigue testing machine through the connecting shaft.

[0013] Furthermore, the main chuck includes chuck plate 1, chuck plate 2 and chuck plate 3; chuck plate 1 is connected to chuck plate 3 through chuck plate 2, and the side of chuck plate 2 away from chuck plate 1 and chuck plate 3 is connected to the main body.

[0014] Furthermore, a first groove is formed between the first chuck plate, the second chuck plate and the third chuck plate, and the first groove is connected to or separated from the three parts of the sample through a pin shaft.

[0015] Furthermore, the main body includes a front panel, side panels and a rear panel; the front panel is connected to the rear panel through the side panels, the side panels are connected to the connecting shaft, and a second groove is formed between the front panel, the side panels and the rear panel.

[0016] Furthermore, the main body also includes first through holes, which are respectively arranged on the front panel and the rear panel, and there are m first through holes, where m is a positive integer.

[0017] A method for using a biaxial tensile fatigue test device applicable to marine engineering materials, the method is applied to the biaxial tensile fatigue test device applicable to marine engineering materials, the method comprises the following steps:

[0018] Step 1: Installation of the main clamping assembly: first connect the lower main clamping assembly to the T-block on the workbench; then connect the upper main clamping assembly to the bottom plate of the fatigue testing machine;

[0019] Step 2: Installation of the tensile specimen: Install the three specimens at the corresponding positions of the tensile specimen into the lower main clamping assembly and the upper main clamping assembly in order; then connect the left auxiliary clamp and the right auxiliary clamp to the three specimens at the corresponding positions through the pins;

[0020] Step 3. Adjust the loading ratio: connect one end of the connecting rod to the two ends of the two auxiliary clamping assemblies through a pin, and connect the other end of the connecting rod to the first through holes at the required proportional positions of the upper main clamping assembly and the lower main clamping assembly through a pin; adjust the fatigue testing machine to conduct a fatigue test.

[0021] Compared with the prior art, the biaxial tensile fatigue test device and the use method thereof for marine engineering materials described in the present invention have the following beneficial effects:

[0022] By setting the device, the load ratio on the two axes can be adjusted at will on the basis of simplifying the structure of the device and reducing the cost of the device, thereby improving the diversity and flexibility of the loading form. By setting the method, it is beneficial to improve the efficiency of disassembly and assembly of the device and the sample holder, shorten the cycle of sample detection, and improve the efficiency of sample detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which constitute part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. In the accompanying drawings:

[0024] Figure 1It is the overall structure diagram of the biaxial tension fatigue test device;

[0025] Figure 2 It is a schematic diagram of the exploded view of the biaxial tension fatigue test device;

[0026] Figure 3 This is a partial enlarged schematic diagram of point B in the exploded view of the biaxial tension fatigue test device;

[0027] Figure 4 It is a schematic diagram of the overall structure of the cross-shaped biaxial tensile fatigue specimen;

[0028] Figure 5 This is a schematic diagram of the cut-off point A_A in the overall structure of the cross-shaped biaxial tension fatigue specimen.

[0029] Description of reference numerals: 1. main clamping assembly; 11. main clamping head; 111. clamping head plate 1; 112. clamping head plate 2; 113. clamping head plate 3; 114. first groove; 115. first connecting hole; 12. main body; 121. front panel; 1211. first arc edge; 1212. second arc edge; 122. side panel; 123. rear panel; 1231. third arc edge; 1232. fourth arc edge; 124. second groove; 125. first through hole; 13. connecting shaft; 14. flange assembly; 141. flange; 1 42. Flange top screw; 15. Upper main clamping assembly; 16. Lower main clamping assembly; 2. Auxiliary clamping assembly; 21. First clamping plate; 22. Second clamping plate; 23. Third clamping plate; 24. Third groove; 25. Second connecting hole; 26. Second through hole; 27. Left auxiliary clamp; 28. Right auxiliary clamp; 3. Connecting rod; 31. Third through hole; 4. Workbench; 41. Table; 42. T-block; 43. T-groove; 5. Tensile specimen; 51. Specimen part 1; 52. Specimen part 2; 53. Specimen part 3; 54. Specimen hole. DETAILED DESCRIPTION

[0030] The inventive concepts of the present disclosure will be described below using terms commonly used by those skilled in the art to convey the essence of their work to other persons skilled in the art. However, these inventive concepts can be embodied in many different forms and should not be considered limited to the embodiments described herein.

[0031] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0032] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0033] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0034] In order to solve the problem that the biaxial tensile test device in the prior art cannot simultaneously meet the requirements of simplifying the device structure and realizing that the load ratio on the two axes can be adjusted at will; this embodiment proposes a biaxial tensile fatigue test device suitable for marine engineering materials and a method of using the same, wherein the biaxial tensile fatigue test device suitable for marine engineering materials is a cross-shaped biaxial tensile fatigue specimen and a mechanical biaxial tensile fatigue test device with a variable loading ratio suitable for marine engineering materials, comprising a main clamping assembly 1, a sub-clamping assembly 2, a connecting rod 3 and a workbench 4. The main clamping assembly 1 and the sub-clamping assembly 2 are both connected to the tensile specimen 5. Two main clamping assemblies 1 and two sub-clamping assemblies 2 are provided, and the two ends of the two sub-clamping assemblies 2 are respectively connected to one end of the connecting rod 3, and the other end of the connecting rod 3 is respectively connected to one end of the two main clamping assemblies 1 in a movable manner. The other ends of the two main clamping assemblies 1 are respectively connected to the workbench 4 and the fatigue testing machine. Among them, the tensile specimen 5 is respectively connected to the main clamping assembly 1 and the sub-clamping assembly 2 through a pin shaft. The two ends of the connecting rod 3 are connected to the main clamping assembly 1 and the auxiliary clamping assembly 2 respectively through pins.

[0035] By cooperating with the setting of the fatigue testing machine, the tensile specimen 5 can be subjected to a biaxial tensile fatigue test with a variable loading ratio. It is also possible to adjust the load ratio on the two axes at will on the basis of simplifying the structure of the device and reducing the cost of the device, thereby improving the diversity and flexibility of the loading form.

[0036] The tensile specimen 5 is a cross-shaped structure. The tensile specimen 5 includes a specimen part 51, a specimen part 52 and a specimen part 53. The specimen part 51 is connected to the specimen part 53 through the specimen part 52, and the specimen part 53 is respectively connected to the main clamping assembly 1 and the auxiliary clamping assembly 2. Specifically, four specimen parts 53 are provided; the four specimen parts 53 are respectively connected to the main clamping assembly 1 and the auxiliary clamping assembly 2 at the corresponding positions. Among them, the specimen part 51 is circular, the specimen part 52 is a circular ring, and the four specimen parts 53 are evenly distributed on the outer wall of the specimen part 52 along the circumference with the specimen part 51 as the center. The thickness L1 of the specimen part 51 is ≤ the thickness L2 of the specimen part 52 ≤ the thickness L3 of the specimen part 53. L1, L2, and L3 are all positive numbers, and the specific values ​​are set according to the needs. The specimen part 52 is smoothly connected to the specimen part 51, which is used to facilitate the use as a transition section of the tensile specimen 5, and plays the role of connecting the specimen part 51 and the specimen part 53. The first sample part 51 is the working section of the tensile sample 5, which is used to facilitate the fatigue testing machine to test the tensile sample 5. The third sample part 53 is the clamping part of the tensile sample 5, which is used to improve the convenience of disassembly and assembly between the tensile sample 5 and the device. In addition, the tensile sample 5 includes a sample hole 54, which is set on the third sample part 53. At least four sample holes 54 are set, and the sample holes 54 are used to facilitate the connection between the tensile sample 5 and the device.

[0037] By setting the cross-shaped structure of the tensile specimen 5, the stability of the structure of the tensile specimen 5 can be guaranteed, and the connection between the tensile specimen 5 and the main clamping assembly 1 and the auxiliary clamping assembly 2 can be facilitated. After the device changes to different loading ratios, the tensile specimen 5 can still be tested accordingly, reducing the need to frequently change the position of the specimen when performing a biaxial tensile fatigue test on the specimen, thereby helping to improve the efficiency of the specimen test.

[0038] The main clamping assembly 1 includes a main chuck 11, a main body 12 and a connecting shaft 13. One end of the main body 12 is connected to the tensile specimen 5 through the main chuck 11, and the other end of the main body 12 is connected to the workbench 4 or the fatigue testing machine through the connecting shaft 13. The main clamping assembly 1 also includes a flange assembly 14, the inner wall of the flange assembly 14 is in contact with the outer wall of the connecting shaft 13, and the side of the flange assembly 14 away from the main body 12 is in contact with the workbench 4 or the fatigue testing machine. The flange assembly 14 includes a flange 141 and a flange top screw 142, and the flange top screw 142 is arranged in the flange 141 for fixing the flange 141. The arrangement of the flange assembly 14 can be used to eliminate gaps, and can also be used to adjust the distance between the device and the workbench 4, or the device and the fatigue testing machine.

[0039] The main chuck 11 includes a chuck plate 111, a chuck plate 112 and a chuck plate 113. The chuck plate 111 is connected to the chuck plate 113 through the chuck plate 112, and the chuck plate 112 is connected to the main body 12 at one side away from the chuck plate 111 and the chuck plate 113. A first groove 114 is formed between the chuck plate 111, the chuck plate 112 and the chuck plate 113, and the first groove 114 is connected to or separated from the third sample part 53 of the tensile sample 5 through a pin. In addition, the main chuck 11 includes a first connecting hole 115, which is respectively set on the chuck plate 111 and the chuck plate 113, and the first connecting hole 115 of the chuck plate 111 corresponds to the setting positions of the first connecting hole 115 of the chuck plate 113 and the sample hole 54 of the third sample part 53. When the tensile specimen 5 is connected to the main chuck 11, the first connection holes 115 on the chuck plate 111 and the chuck plate 113 correspond to the setting positions of the sample holes 54. When the tensile specimen 5 is connected to the main chuck 11, the pins are set in the first connection holes 115 and the sample holes 54. Under the action of the pins, the tensile specimen 5 is fixedly connected to the main chuck 11. The first connection holes 115 and the sample holes 54 are both set n, and n is a positive integer.

[0040] The arrangement of different first connecting holes 115 on the main chuck 11 facilitates the detachable connection between the tensile specimen 5 and the main chuck 11 under the action of the pin, improves the efficiency of assembly and disassembly between the tensile specimen 5 and the main chuck 11, and can also improve the tightness of the connection between the tensile specimen 5 and the main chuck 11.

[0041] The main body 12 includes a front panel 121, a side panel 122 and a rear panel 123. The front panel 121 is connected to the rear panel 123 through the side panel 122, and the side panel 122 is connected to the connecting shaft 13. A second groove 124 is formed between the front panel 121, the side panel 122 and the rear panel 123. The second groove 124 is used to provide an installation space for the connecting rod 3.

[0042] The front panel 121 and the rear panel 123 are arranged in parallel. The front panel 121 includes a first arc edge 1211 and a second arc edge 1212, one end of the first arc edge 1211 is connected to the front side of one end of the side panel 122, and the other end of the first arc edge 1211 is connected to the front side of the other end of the side panel 122 through the second clamping plate 112 and the second arc edge 1212 in sequence.

[0043] The rear panel 123 includes a third arc edge 1231 and a fourth arc edge 1232. One end of the third arc edge 1231 is connected to the rear side of one end of the side panel 122. The other end of the third arc edge 1231 is connected to the rear side of the other end of the side panel 122 through the second clamping plate 112 and the fourth arc edge 1232 in sequence. The first arc edge 1211 is arranged in parallel with the third arc edge 1231, and the second arc edge 1212 is arranged in parallel with the fourth arc edge 1232.

[0044] The arrangement of different arc edges is conducive to improving the convenience of connection between the connecting rod 3 and the main clamping assembly 1. It can also realize that the connecting rod 3 can quickly change different loading ratios, shorten the experimental cycle, and improve the efficiency of the experiment.

[0045] The main body 12 also includes a first through hole 125, which is respectively arranged on the front panel 121 and the rear panel 123. The first through hole 125 on the front panel 121 corresponds to the setting position of the first through hole 125 on the rear panel 123. There are 8m first through holes 125, where m is a positive integer. The first through holes 125 are respectively arranged along the first arc edge 1211, the second arc edge 1212, the third arc edge 1231, and the fourth arc edge 1232. At least m first through holes 125 are arranged on each arc edge to facilitate providing different load ratios for the tensile specimen 5. The connecting rod 3 is connected to the first through holes 125 at different positions on the main clamping assembly 1 in a detachable manner. In this embodiment, m is 8.

[0046] By cooperating with the first through hole 125, the connecting rod 3 and the auxiliary clamping assembly 2, a plurality of through holes are provided in the main clamping assembly 1 for clamping the connecting rod 3. When the connecting rod 3 is installed in different clamping hole positions, the ratio of the stress on the axis where the main clamping assembly 1 is located to the stress on the axis where the auxiliary clamping assembly 2 is located will be different, thereby achieving different load ratios. In this way, the device can have the advantages of simple structure and low cost of the conventional mechanical biaxial tensile testing method, and can also achieve a variety of loading ratios with different loads on the two axes.

[0047] The auxiliary clamping assembly 2 includes a first clamping plate 21, a second clamping plate 22 and a third clamping plate 23. The first clamping plate 21 is connected to the third clamping plate 23 through the second clamping plate 22. A third groove 24 is formed between the first clamping plate 21, the second clamping plate 22 and the third clamping plate 23; the three parts 53 of the tensile specimen 5 and the connecting rod 3 are connected or separated from the third groove 24 through a pin. Among them, the auxiliary clamping assembly 2 also includes a second connecting hole 25 and a second through hole 26. The second connecting hole 25 and the second through hole 26 are respectively arranged on the first clamping plate 21 and the third clamping plate 23. The second connecting hole 25 and the second through hole 26 on the first clamping plate 21 correspond to the second connecting hole 25 and the second through hole 26 on the third clamping plate 23. The second connecting hole 25 is arranged at one end of the first clamping plate 21 and the third clamping plate 23 facing the tensile specimen 5, and the second through hole 26 is arranged at one end of the first clamping plate 21 and the third clamping plate 23 away from the tensile specimen 5. The second connection holes 25 on the first clamping plate 21 and the third clamping plate 23 are arranged in a one-to-one correspondence with the arrangement positions of the sample holes 54. When the tensile sample 5 is connected to the auxiliary clamping assembly 2, the pin is arranged in the second connection hole 25 and the sample hole 54, and the tensile sample 5 is fixedly connected to the auxiliary clamping assembly 2 under the action of the pin.

[0048] The coordinated arrangement of the components in the auxiliary clamping assembly 2 is conducive to simplifying the structure of the device and reducing the cost of the device. Under the action of the connecting rod 3 and the main clamping assembly 1, the stability and reliability of the device in clamping the tensile specimen 5 can be improved.

[0049] The connecting rod 3 includes a third through hole 31, which is respectively set at both ends of the connecting rod 3. The setting of the third through hole 31 is conducive to laying the foundation for the connection between the connecting rod 3 and the main clamping assembly 1 and the auxiliary clamping assembly 2. The workbench 4 includes a table body 41 and a T-block 42. The T-block 42 is embedded in the table body 41 in a slidable manner, and the top of the T-block 42 is connected to the end of the connecting shaft 13 of the main clamping assembly 1 away from the main body 12. Among them, the T-block 42 is threadedly connected to the connecting shaft 13. The table body 41 includes a T-groove 43, which is set on the top of the table body 41, and the bottom of the table body 41 is fixedly set on a horizontal plane; the T-block 42 is set in the T-groove 43 in a slidable manner. At least one T-groove 43 is set. The T-block 42 can be set in different T-grooves 43 as needed, or on the same workbench 4, so that experiments with different loading ratios of multiple tensile specimens 5 can be carried out simultaneously.

[0050] By setting the connecting rod 3 and the pin, the difficulty of disassembling and assembling the device can be effectively simplified, and the convenience of disassembling and assembling the device can be achieved. The split setting of the device can also improve the convenience of disassembling and assembling between the device and the sample. In addition, the experimental device in this application is driven by a uniaxial fatigue testing machine, which greatly improves the applicability of the device.

[0051] Two main clamping assemblies 1 and two auxiliary clamping assemblies 2 are provided. The two main clamping assemblies 1 are respectively an upper main clamping assembly 15 and a lower main clamping assembly 16. The two auxiliary clamping assemblies 2 are respectively a left auxiliary clamp 27 and a right auxiliary clamp 28. The upper and lower ends of the left auxiliary clamp 27 and the right auxiliary clamp 28 are respectively connected to one end of the connecting rod 3 through a pin shaft, and the other end of the connecting rod 3 is respectively connected to one end of the upper main clamping assembly 15 and the lower main clamping assembly 16 through a pin shaft in a movable manner; the other end of the upper main clamping assembly 15 is connected to the bottom plate of the fatigue testing machine; the other end of the lower main clamping assembly 16 is connected to the workbench 4. The upper main clamping assembly 15, the lower main clamping assembly 16, the left auxiliary clamp 27, and the right auxiliary clamp 28 are all connected to the three parts 53 of the specimen at the corresponding position of the tensile specimen 5. The ends of the four sample three parts 53 away from the sample two parts 52 are respectively arranged in the first grooves 114 of the upper main clamping assembly 15 and the lower main clamping assembly 16, and the third grooves 24 of the left auxiliary clamp 27 and the right auxiliary clamp 28. The sample hole 54 is respectively aligned with the center of the first connecting hole 115 and the second connecting hole 25, and the pin is arranged in the first connecting hole 115 and the sample hole 54, or the pin is arranged in the second connecting hole 25 and the sample hole 54. In this embodiment, eight connecting rods 3 are arranged. Twenty-eight pins are arranged. Eight first through holes 125 with different positions are arranged on each arc edge of the main body 12 in the main clamping assembly 1, and the first through holes 125 are used to connect the connecting rod 3. When the end of the connecting rod 3 away from the auxiliary clamping assembly 2 is clamped at the first through holes 125 at different positions through the pin, different load proportions correspond to each other. In the present application, the ratios of the load on the axis where the auxiliary clamping component 2 is located to the load on the axis at eight different positions of each arc edge of the main clamping component 1 are: -1:1, -4:5, -1:2, -1:4, 1:4, 1:2, 4:5, 1:1.

[0052] Different from the existing mechanical biaxial tensile test device which can only realize one loading mode of load ratio, the present application can realize eight loading modes of different load ratios. By setting the first through holes 125 at eight different positions, it can be used to install the connecting rod 3 and realize the effect of variable biaxial load ratio.

[0053] A method for using a biaxial tensile fatigue test device applicable to marine engineering materials, the method is applied to the biaxial tensile fatigue test device applicable to marine engineering materials, the method comprises the following steps:

[0054] Step 1: Installation of the main clamping assembly 1: first connect the lower main clamping assembly 16 to the T-block 42 on the workbench 4; then connect the upper main clamping assembly 15 to the bottom plate of the fatigue testing machine;

[0055] Step 2: Install the tensile specimen 5: Install the three specimen parts 53 at the corresponding positions of the tensile specimen 5 in the lower main clamping assembly 16 and the upper main clamping assembly 15 in order; then connect the left auxiliary clamp 27 and the right auxiliary clamp 28 to the three specimen parts 53 at the corresponding positions through the pins;

[0056] Step 3, adjustment of loading ratio: connect one end of the connecting rod 3 to the two ends of the two auxiliary clamping assemblies 2 through a pin shaft, and connect the other end of the connecting rod 3 to the first through hole 125 at the required proportional position of the upper main clamping assembly 15 and the lower main clamping assembly 16 through a pin shaft; adjust the fatigue testing machine to conduct fatigue test.

[0057] The arrangement of the method is helpful to improve the efficiency of assembly and disassembly of the device and the sample holder, shorten the cycle of sample detection, and improve the efficiency of sample detection.

[0058] Step one includes:

[0059] Step S11: firstly connect the connecting shaft 13 of the lower main clamping assembly 16 to the T-block 42 on the workbench 4 through threads, and then fix the lower main clamping assembly 16 and the T-block 42 through the flange assembly 14;

[0060] Step S12: Connect the connecting shaft 13 of the upper main clamping assembly 15 to the bottom plate of the fatigue testing machine through threads, and then fix the upper main clamping assembly 15 and the bottom plate of the fatigue testing machine through the flange assembly 14.

[0061] Step 2 includes:

[0062] Step S21: fix the lower third specimen part 53 of the tensile specimen 5 in the first groove 114 of the lower main clamping assembly 16 through a pin;

[0063] Step S22: adjusting the height of the indenter of the fatigue testing machine, and fixing the upper third specimen portion 53 of the tensile specimen 5 in the first groove 114 of the upper main clamping assembly 15 through a pin;

[0064] Step S23: The left third sample portion 53 of the tensile sample 5 is arranged in the third groove 24 of the left auxiliary clamp 27 via a pin;

[0065] Step S24: The third specimen portion 53 on the right side of the tensile specimen 5 is set in the third groove 24 of the right auxiliary chuck 28 via a pin.

[0066] Unlike the current hydraulic biaxial fatigue test equipment, which can achieve variable ratio loading, the equipment cost is often millions; the use of the mechanical device of tens of thousands of yuan in this application combined with the uniaxial fatigue test equipment can achieve biaxial fatigue loading with variable loading ratio for the cross-shaped specimen, which has the advantages of low cost, simple structure, and easy to achieve test conditions.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A biaxial tensile fatigue test device suitable for marine engineering materials, characterized in that: The invention comprises a main clamping assembly (1), a secondary clamping assembly (2), a connecting rod (3) and a workbench (4); the main clamping assembly (1) and the secondary clamping assembly (2) are both connected to a tensile test specimen (5); two main clamping assemblies (1) and two secondary clamping assemblies (2) are provided, the two ends of the two secondary clamping assemblies (2) are respectively connected to one end of the connecting rod (3), and the other end of the connecting rod (3) is respectively connected to one end of the two main clamping assemblies (1) in a movable manner; the other ends of the two main clamping assemblies (1) are respectively connected to the workbench (4) and the fatigue testing machine.

2. A biaxial tension fatigue test device suitable for marine engineering materials according to claim 1, characterized in that: The tensile test specimen (5) is connected to the main clamping component (1) and the auxiliary clamping component (2) respectively through a pin shaft.

3. A biaxial tensile fatigue test device suitable for marine engineering materials according to claim 1, characterized in that: The tensile specimen (5) comprises a first specimen (51), a second specimen (52) and a third specimen (53); the first specimen (51) is connected to the third specimen (53) via the second specimen (52); and the third specimen (53) is respectively connected to a main clamping assembly (1) and a secondary clamping assembly (2).

4. A biaxial tension fatigue test device for marine materials according to claim 3, characterized in that: The thickness L1 of the first sample part (51) ≤ the thickness L2 of the second sample part (52) ≤ the thickness L3 of the third sample part (53).

5. A biaxial tension fatigue test device suitable for marine engineering materials according to claim 3, characterized in that: The main clamping assembly (1) comprises a main clamp (11), a main body (12) and a connecting shaft (13); one end of the main body (12) is connected to the tensile specimen (5) through the main clamp (11), and the other end of the main body (12) is connected to a workbench (4) or a fatigue testing machine through the connecting shaft (13).

6. A biaxial tension fatigue test device for marine materials according to claim 5, characterized in that: The main chuck (11) comprises a chuck plate (111), a chuck plate (112) and a chuck plate (113); the chuck plate (111) is connected to the chuck plate (113) via the chuck plate (112), and the side of the chuck plate (112) away from the chuck plate (111) and the chuck plate (113) is connected to the main body (12).

7. A biaxial tension fatigue test device for marine engineering materials according to claim 6, characterized in that: A first groove (114) is formed between the first chuck plate (111), the second chuck plate (112) and the third chuck plate (113), and the first groove (114) is connected to or separated from the third sample part (53) through a pin shaft.

8. The biaxial tension fatigue test device for marine materials according to claim 5, characterized in that: The main body (12) comprises a front panel (121), a side panel (122) and a rear panel (123); the front panel (121) is connected to the rear panel (123) via the side panel (122), the side panel (122) is connected to the connecting shaft (13), and a second groove (124) is formed between the front panel (121), the side panel (122) and the rear panel (123).

9. A biaxial tension fatigue test device for marine materials according to claim 8, characterized in that: The main body (12) further comprises first through holes (125), which are respectively arranged through the front panel (121) and the rear panel (123), and there are 8m first through holes (125), where m is a positive integer.

10. A method for using a biaxial tensile fatigue test device suitable for marine engineering materials, characterized in that: The method is applied to a biaxial tensile fatigue test device applicable to marine engineering materials according to any one of claims 1 to 9, and the method comprises the following steps: Step 1: Installation of the main clamping assembly (1): first connect the lower main clamping assembly (16) to the T-block (42) on the workbench (4); then connect the upper main clamping assembly (15) to the bottom plate of the fatigue testing machine; Step 2, installation of the tensile specimen (5): install the three specimen parts (53) at corresponding positions of the tensile specimen (5) in the lower main clamping assembly (16) and the upper main clamping assembly (15) in order; then connect the left auxiliary clamp (27) and the right auxiliary clamp (28) to the three specimen parts (53) at corresponding positions through a pin shaft; Step 3, adjusting the loading ratio: connect one end of the connecting rod (3) to the two ends of the two auxiliary clamping assemblies (2) through a pin shaft, and connect the other end of the connecting rod (3) to the first through hole (125) at the required proportional position of the upper main clamping assembly (15) and the lower main clamping assembly (16) through a pin shaft; adjust the fatigue testing machine to perform a fatigue test.

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