Compression-shear composite test method for typical piece of grating structure
By applying diagonal and normal loads to typical grid structure components and monitoring them with strain gauges and pressure sensors, the problem of insufficient mechanical properties caused by fiber accumulation was solved, and efficient mechanical property testing of grid structures was achieved.
Patent Information
- Application Number
- CN202511380762.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-25
- Publication Date
- 2025-11-21
AI Technical Summary
In grid structures, fiber accumulation and bending at intersections lead to insufficient fiber volume fraction, reducing the mechanical properties of the structure, especially exhibiting weak strength and stiffness under combined compressive and shear loads.
The compression-shear composite test method for typical grid structures was adopted. By installing detectors on typical grid structures, loads of the same magnitude were applied along the diagonal and normal directions, and multiple third and fourth loads were applied. The number of loads and detector parameters were recorded, and strain gauges and pressure sensors were used to monitor the mechanical properties.
Accurate measurement of the mechanical performance of grid structures under static and fatigue conditions provides strong evidence to improve the accuracy of mechanical performance testing and provides a reliable basis for the application of grid structures.
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Figure CN120992370A_ABST
Abstract
Description
Technical Field
[0001] This disclosure relates to the field of grid structure testing technology, and more specifically, to a method for a combined compression-shear test of a typical grid structure component. Background Technology
[0002] With the continuous development of aircraft structures, the unique environment and higher performance requirements of aircraft bring new challenges to structural design, such as ultra-lightweight structures, optimal configuration design, and multifunctional structures. Therefore, finding an efficient, functional, and low-cost structural form has become a goal pursued by engineers and researchers. Advanced grid structures combine the advantages of new material technologies and new structural designs, offering strong design flexibility and excellent performance, and have attracted much attention. Internationally, it is considered a promising new generation of advanced lightweight ultra-tough materials and has gradually gained importance in the engineering community. Currently, related research and applications have been carried out both domestically and internationally. In practical applications, its unparalleled application prospects are gradually emerging, and it is expected to bring new breakthroughs to the development of aircraft structures.
[0003] The first problem to solve during the fabrication of advanced grid structures is that the reinforcing ribs of the grid structure are intersecting, which causes fiber accumulation and bending at the intersections. This results in the fiber volume fraction of the grid structure being less than 50%, reducing the mechanical properties of the structure and creating weak points in strength and stiffness, which is particularly evident under combined compressive and shear loads. Therefore, it is essential to thoroughly evaluate the mechanical behavior of the grid structure under combined compressive and shear loads before its application.
[0004] It should be noted that the information disclosed in the background section above is only used to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention
[0005] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a composite compression-shear test method for typical grid structures. This method improves the accuracy of grid structure testing while ensuring consistent load application across all regions of the grid structure, providing strong evidence for the application of grid structures.
[0006] According to one aspect of this disclosure, a method for combined compression and shear testing of a typical grid structure is provided, comprising:
[0007] Provide typical grid structure components;
[0008] Install detectors on the typical component of the grid structure;
[0009] A first load is applied to the typical grid structure along the diagonal direction; a second load is applied to the typical grid structure along the normal direction, wherein the first load and the second load are of the same magnitude and are applied simultaneously.
[0010] Multiple third loads are applied to the typical grid structure along the diagonal direction of the typical grid structure, and multiple fourth loads are applied to the typical grid structure along the normal direction of the typical grid structure, wherein the third loads and the fourth loads are of the same magnitude and are applied simultaneously.
[0011] Record the number of times the third load and the fourth load are applied to the typical component of the grid structure, as well as the parameters on the detector.
[0012] According to one embodiment of the present disclosure, installing a detector on the typical grid structure includes:
[0013] Multiple strain gauges are installed on the typical grid structure component;
[0014] The typical grid structure component is divided into multiple inspection areas;
[0015] A pressure sensor is placed at the center of each detection area.
[0016] According to one embodiment of the present disclosure, the strain gauge includes a first sub-strain gauge, a second sub-strain gauge, a third sub-strain gauge, and a fourth sub-strain gauge.
[0017] According to one embodiment of the present disclosure, mounting multiple strain gauges on the typical grid structure includes:
[0018] The grid opening is designed to have four sides, a first diagonal, and a second diagonal;
[0019] The first sub-strain gauge and the fourth sub-strain gauge are positioned at both ends of the first diagonal; and the first sub-strain gauge and the fourth sub-strain gauge are arranged symmetrically about the length direction of the second diagonal.
[0020] The second sub-strain gauge and the third sub-strain gauge are disposed on adjacent sides, the second sub-strain gauge and the third sub-strain gauge are connected, and the second sub-strain gauge and the third sub-strain gauge are symmetrically arranged about the second diagonal.
[0021] According to an embodiment of the present disclosure, a first load is applied to the grid structure sample along a diagonal direction of the grid structure sample; a second load is applied to the grid structure sample along a normal direction of the grid structure sample, wherein the first load and the second load have the same magnitude and are applied simultaneously, including:
[0022] The grid structure sample is divided into multiple groups, wherein the multiple groups of the grid structure sample include a first group of grid structure samples and a remaining group of grid structure samples;
[0023] A preset load is set;
[0024] The first group of grid structure samples is subjected to a test by applying a load;
[0025] The remaining group of grid structure samples is subjected to a test by applying a load.
[0026] According to an embodiment of the present disclosure, the test on the first group of grid structure samples by applying a load includes:
[0027] The first initial load of the first load and the second load is set as ten percent of the preset load, and the first load and the second load are gradually increased to the first group of grid structure samples, and the process is repeated multiple times;
[0028] The second initial load of the first load and the second load is set as five percent of the preset load, and the first load and the second load are gradually increased to the first group of grid structure samples until the first group of grid structure samples is destroyed.
[0029] According to an embodiment of the present disclosure, the second initial load of the first load and the second load is set as five percent of the preset load, and the first load and the second load are gradually increased to the first group of grid structure samples until the first group of grid structure samples is destroyed, including:
[0030] When the first load and the second load are gradually increased to the first group of grid structure samples, the rate of each load increase is 2 mm / min, and the pause time of each load increase is 1 s.
[0031] According to an embodiment of the present disclosure, the test on the remaining group of grid structure samples by applying a load includes:
[0032] The failure load of the first group of grid structure samples is recorded;
[0033] The first load and the second load are gradually increased to the remaining group of grid structure samples by 5% of the preset load, and the second initial load is 5% of the preset load;
[0034] When the first load and the second load reach 80% of the failure load, the remaining group of grid structure samples is gradually increased by 2% of the failure load;
[0035] The remaining group of grid structure samples is loaded to failure.
[0036] According to an embodiment of the present disclosure, a plurality of third loads are applied to the grid structure sample in the diagonal direction of the grid structure sample, and a plurality of fourth loads are applied to the grid structure sample in the normal direction of the grid structure sample, wherein the third load and the fourth load have the same size and are loaded at the same time, including:
[0037] Setting the maximum load of the fatigue test;
[0038] Applying a plurality of third loads and fourth loads to the grid structure sample;
[0039] The third load and the fourth load are gradually increased after being loaded more than 200,000 times.
[0040] According to an embodiment of the present disclosure, the third load and the fourth load are gradually increased after being loaded more than 200,000 times, including:
[0041] The third load and the fourth load are increased by 5% each time.
[0042] Beneficial effects:
[0043] By simultaneously loading the first load in the diagonal direction of the grid structure sample and the second load in the normal direction of the grid structure sample, the mechanical performance of the grid structure in the static state can be measured. By simultaneously loading a plurality of third loads in the diagonal direction of the grid structure sample and a plurality of fourth loads in the normal direction of the grid structure sample, the mechanical performance of the grid structure in the fatigue state can be measured. Further, according to the number of cycles of the third load and the fourth load applied to the grid structure sample, the mechanical performance of the grid structure sample can be obtained macroscopically. Through the relevant parameters on the detector, the mechanical performance of the grid structure sample can be obtained microscopically. In this way, comprehensive analysis can accurately obtain the mechanical performance of the grid structure sample, providing strong evidence for the application of the grid structure.
[0044] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF DRAWINGS
[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and serve to explain the principles of the present disclosure. It is readily apparent to one skilled in the art that the following figures are merely some embodiments of the present disclosure, and other figures can be obtained by one of ordinary skill in the art without any creative effort, based on these figures.
[0046] Figure 1 For an embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0047] Figure 2 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0048] Figure 3 For an embodiment of the present disclosure, a schematic diagram of a distribution of pressure sensors on a typical member of a grid structure.
[0049] Figure 4 For an embodiment of the present disclosure, a schematic diagram of a distribution of strain gauges on a typical member of a grid structure.
[0050] Figure 5 For related art, a schematic diagram of a strain gauge disposed on a grid hole.
[0051] Figure 6 For an embodiment of the present disclosure, a schematic diagram of a strain gauge disposed on a grid hole.
[0052] Figure 7 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0053] Figure 8 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0054] Figure 9 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0055] Figure 10 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0056] Figure 11 For another embodiment of the present disclosure, a flow chart of a compression-shear composite test method for a typical member of a grid structure.
[0057] Figure 12 Fig. 3 is a schematic view of a third load and a fourth load applied to a grid structure typical part in a compression-shear combined test method according to an embodiment of the present disclosure.
[0058] Figure 13 Fig. 4 is a schematic view of an overall structure of a grid structure typical part compression-shear combined test device according to an embodiment of the present disclosure.
[0059] Figure 14 Fig. 5 is an enlarged view of A of Fig. 4. Figure 13
[0060] BRIEF DESCRIPTION OF DRAWINGS1: a grid structure typical part; 11: a reinforcing rib; 12: a grid hole; 121: a first sub-side; 122: a second sub-side; 123: a third sub-side; 124: a fourth sub-side; 2: a detector; 21: a strain gauge; 211: a first sub-strain gauge; 212: a second sub-strain gauge; 213: a third sub-strain gauge; 214: a fourth sub-strain gauge; 22: a pressure sensor; 3: a shearing mechanism; 31: a double-ear clamp; 32: a shearing cylinder; 33: a shearing frame; 4: a pressure applying mechanism; 41: a stopper; 42: a steel wire rope; 43: a connecting rod; 44: a pressure applying cylinder; A1: a first diagonal line; A2: a second diagonal line. DETAILED DESCRIPTION
[0061] Example embodiments now will be described more fully hereinafter with reference to the accompanying drawings. Example embodiments, however, can be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. Like reference numerals refer to like elements throughout the specification. It will be understood that, although the terms first, second, first, etc. can be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of example embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.
[0062] Although relative terms such as "upper", "lower", etc. are used herein to describe one component's relationship to another component of a figure, such terms are used herein for convenience only and are not necessarily limiting. It will be further understood that, when a figure is turned upside down, i.e., when the figure is flipped over, an element described as "upper" will become an element described as "lower". When a structure is "on" another structure, it can mean that the structure is formed integrally with the other structure or that the structure is "directly" on the other structure or that the structure is "indirectly" on the other structure via another structure.
[0063] In the related art, the reinforcing ribs of the grid structure are intersected with each other, and fiber accumulation and fiber bending at the intersection structure can cause the fiber volume fraction to be less than 50%, which further causes the grid structure to form a weak point in strength and stiffness, and reduces the mechanical properties of the grid structure. Therefore, the mechanical properties of the grid structure need to be accurately tested before the grid structure is applied.
[0064] Based on this, referring to Figure 1 The embodiment of the present disclosure provides a typical piece of grid structure compression-shear composite test method. The test method can improve the detection accuracy of the mechanical properties of the grid structure under the premise of ensuring that each area of the grid structure is subjected to uniform load in the test. The test method comprises the following steps:
[0065] S01: providing a typical piece of grid structure 1;
[0066] S02: installing a detector 2 on the typical piece of grid structure 1;
[0067] S03: loading a first load on the typical piece of grid structure 1 along the diagonal direction of the typical piece of grid structure 1, and loading a second load on the typical piece of grid structure 1 along the normal direction of the typical piece of grid structure 1, wherein the first load and the second load have the same size and are loaded at the same time;
[0068] S04: applying a plurality of third loads to the typical piece of grid structure 1 along the diagonal direction of the typical piece of grid structure 1, and applying a plurality of fourth loads to the typical piece of grid structure 1 along the normal direction of the typical piece of grid structure 1, wherein the third loads and the fourth loads have the same size and are loaded at the same time;
[0069] S05: recording the number of times of loading the third load and the fourth load on the typical piece of grid structure 1 and the parameters on the detector 2.
[0070] In the embodiment of the present disclosure, by loading the first load on the diagonal direction of the typical piece of grid structure 1 and loading the second load on the normal direction of the typical piece of grid structure 1 at the same time, the mechanical performance of the grid structure in the static state can be measured. By loading a plurality of third loads on the diagonal direction of the typical piece of grid structure 1 and loading a plurality of fourth loads on the normal direction of the typical piece of grid structure 1 at the same time, the mechanical performance of the grid structure in the fatigue state can be measured. Further, according to the cycle number of loading the third load and the fourth load on the typical piece of grid structure 1, the mechanical properties of the typical piece of grid structure 1 can be obtained macroscopically. The related parameters on the detector 2 can be used to obtain the mechanical properties of the typical piece of grid structure 1 microscopically. Therefore, comprehensive analysis can accurately obtain the mechanical properties of the typical piece of grid structure 1, which provides strong evidence for the application of the grid structure.
[0071] The following isFigure 1 The detailed process of each step is explained.
[0072] Referring to Figure 2 In some embodiments of the present disclosure, in step S02, installing the detector 2 on the grid structure sample 1 comprises:
[0073] S021: installing a plurality of strain gauges 21 on the grid structure sample 1;
[0074] Figure 4 In some embodiments of the present disclosure, the distribution of the strain gauges 21 on the grid structure sample 1 is shown in Figure 4 .
[0075] S022: dividing the grid structure sample 1 into a plurality of detection areas;
[0076] S023: arranging a pressure sensor 22 at the center position of each detection area.
[0077] It can be understood that in some embodiments of the present disclosure, the order of installing the strain gauges 21 and the pressure sensor 22 on the grid structure sample 1 is not specifically limited.
[0078] In some embodiments of the present disclosure, dividing the grid structure sample 1 into a plurality of detection areas can reduce the phenomenon that the presence of the reinforcing ribs 11 affects the pressure distribution of the grid structure. At the same time, the corresponding concentrated load of each area to reach the required uniform pressure can be determined by calculating the pressure distribution under the concentrated load of each area in the finite element analysis software.
[0079] Figure 3 For the schematic diagram of the arrangement position of the pressure sensor 22, please refer to Figure 3 In the grid structure sample 1, the pressure sensor 22 is arranged at the center position of each detection area, and the arranged pressure sensor 22 can monitor the pressure near the air inlet during the test process to prevent the grid structure sample from overpressure; at the same time, the pressure sensor 22 arranged at the impact position of the grid structure sample can obtain the pressure value during the impact test process of the grid structure. During the test process, the strain and displacement measurement can be performed after the measurement value of the middle pressure sensor 22 reaches the target value range and stabilizes, which improves the accuracy of the measurement of the grid structure sample.
[0080] Further, the measurement accuracy of the pressure sensor 22 is within two percent of the target value.
[0081] Referring to Figure 6 In some embodiments of the present disclosure, the strain gauge 21 comprises a first sub-strain gauge 211, a second sub-strain gauge 212, a third sub-strain gauge 213, and a fourth sub-strain gauge 214.
[0082] It should be noted that when the grid structure typical piece 1 is tested, since the grid structure has a large number of array distributed grid holes 12, and the strain parameters between adjacent grid holes 12 have important reference value for the mechanical properties of the grid structure typical piece 1, in the prior art, it is difficult to paste the three-way strain gauge 21 between the adjacent grid holes 12 (see Figure 5 ). In the embodiment of the present disclosure, the first sub-strain gauge 211, the second sub-strain gauge 212, the third sub-strain gauge 213 and the fourth sub-strain gauge 214 are used instead of the three-way strain gauge 21 in the prior art for measurement, so that the accuracy of the measurement of the grid structure typical piece 1 is improved while facilitating the measurement of the mechanical properties between adjacent grid holes 12.
[0083] Specifically, referring to Figure 7 , step S021, installing a plurality of strain gauges 21 on the grid structure typical piece 1 includes:
[0084] S2011: setting the grid hole 12 to have four sides, a first diagonal line A1 and a second diagonal line A2;
[0085] S2012: setting the first sub-strain gauge 211 and the fourth sub-strain gauge 214 at both ends of the first diagonal line A1; and setting the first sub-strain gauge 211 and the fourth sub-strain gauge 214 symmetrically about the length direction of the second diagonal line A2;
[0086] S2013: setting the second sub-strain gauge 212 and the third sub-strain gauge 213 on adjacent sides, connecting the second sub-strain gauge 212 and the third sub-strain gauge 213, and setting the second sub-strain gauge 212 and the third sub-strain gauge 213 symmetrically about the second diagonal line A2.
[0087] It should be noted that in the embodiment of the present disclosure, the order of installing the first sub-strain gauge 211, the second sub-strain gauge 212, the third sub-strain gauge 213 and the fourth sub-strain gauge 214 is not specifically limited, as long as the relative order of the first sub-strain gauge 211, the second sub-strain gauge 212, the third sub-strain gauge 213 and the fourth sub-strain gauge 214 is met.
[0088] Referring to Figure 6 , the arrangement of the first sub-strain gauge 211, the second sub-strain gauge 212, the third sub-strain gauge 213 and the fourth sub-strain gauge 214 is described in detail as follows:
[0089] Taking one grid hole 12 as an example, the grid hole 12 includes four sides (for example, a first sub-side 121, a second sub-side 122, a third sub-side 123, and a fourth sub-side 124); wherein the first sub-gauge 211 and the fourth sub-gauge 214 are arranged at the position of the first diagonal line A1 (it can be understood that the first sub-gauge 211 and the fourth sub-gauge 214 are arranged between adjacent grid holes 12), the second sub-gauge 212 is arranged on one side of the second sub-side 122 between adjacent grid holes 12; the third sub-gauge 213 is arranged on one side of the third sub-side 123 between adjacent grid holes 12, and the second sub-gauge 212 and the third sub-gauge 213 are connected to each other.
[0090] Further, in the embodiments of the present disclosure, before processing the data of the grid structure sample 1, the average of the strain parameters measured at the two positions of the first sub-gauge 211 and the fourth sub-gauge 214 is taken as the strain value in the equivalent direction; then the strain values measured by the second sub-gauge 212 and the third sub-gauge 213 are analyzed together with the strain value in the equivalent direction to measure the strain parameters of the grid structure sample 1 at the test point.
[0091] In some embodiments of the present disclosure, referring to Figure 8 In step S03, a first load is applied to the grid structure sample 1 in the diagonal direction of the grid structure sample 1, and a second load is applied to the grid structure sample 1 in the normal direction of the grid structure sample 1, wherein the first load and the second load have the same size and are applied at the same time, including:
[0092] S031: The grid structure sample 1 is divided into multiple groups, wherein the multiple groups of grid structure samples 1 include a first group of grid structure samples 1 and the remaining groups of grid structure samples 1;
[0093] S032: A preset load is set;
[0094] S033: The first group of grid structure samples 1 is loaded with a load for testing;
[0095] S034: The remaining groups of grid structure samples 1 are loaded with a load for testing.
[0096] Specifically, when measuring the first group of grid structure samples 1, a preset load is first set (it can be understood that the preset load can be obtained according to off-site tests, and the embodiments of the present disclosure do not make specific descriptions here). Then, the first group of grid structure samples 1 is tested according to the set load; and the remaining groups of grid structure samples are tested based on the test results of the first group of grid structure samples 1.
[0097] In some embodiments of the present disclosure, referring to Figure 9In step S033, the test of loading the load on the first set of grid structure specimens 1 includes:
[0098] S0331: setting the percentage of the preset load as the first initial load of the first load and the second load, gradually increasing the first load and the second load on the first set of grid structure specimens 1, and repeating multiple times;
[0099] S0332: setting the percentage of the preset load as the second initial load of the first load and the second load, gradually increasing the first load and the second load on the first set of grid structure specimens 1 until the first set of grid structure specimens 1 is destroyed.
[0100] Specifically, when measuring the first set of grid structure specimens 1, the first load and the second load are first set to the percentage of the preset load, and then the first load and the second load are loaded on the grid structure specimens 1 at the same time, and then the first load and the second load are loaded on the grid structure specimens 1 in a step-by-step increasing manner until the preset load is loaded, and repeated multiple times.
[0101] As an example, in some embodiments, the preset load can be increased by the percentage of the preset load. For example, when the percentage of the preset load is set as the first initial load of the first load and the second load, the increased load can be the percentage of the preset load, the percentage of the preset load, the percentage of the preset load, and so on, until the first load and the second load are loaded to the percentage of the preset load. Of course, in other embodiments, the preset load can be increased by the percentage of the preset load, and the embodiments of the present disclosure do not make any further description.
[0102] In the embodiments of the present disclosure, when the first load and the second load are loaded to the percentage of the preset load, the first load and the second load can be repeatedly loaded on the grid structure specimens 1 three times. It should be noted that in the embodiments of the present disclosure, the number of repetitions of the first load and the second load is not limited when the first load and the second load are increased to the percentage of the preset load.
[0103] Further, when the first load and the second load are repeatedly loaded on the grid structure specimens 1 three times, the first load and the second load are set to the percentage of the preset load to reload the grid structure specimens 1 until the grid structure specimens 1 are destroyed.
[0104] In some embodiments of the present disclosure, step S0332: setting the percentage of the preset load as the second initial load of the first load and the second load, gradually increasing the first load and the second load on the first set of grid structure specimens 1 until the first set of grid structure specimens 1 is destroyed includes:
[0105] The first load and the second load are gradually increased to the first group of grid structure samples 1 at a rate of 2 mm / min each time, and the load is stopped for 1 s each time.
[0106] In some embodiments of the present disclosure, referring to Figure 10 In step S034, the remaining group of grid structure samples 1 is loaded with a load for testing, which includes:
[0107] S0341: record the failure load of the first group of grid structure samples;
[0108] S0342: the first load and the second load are gradually increased to the remaining group of grid structure samples 1 at a load of 5% of the preset load as the second initial load;
[0109] S0343: when the first load and the second load are loaded to 80% of the failure load, the remaining group of grid structure samples 1 is gradually increased by 2% of the failure load;
[0110] S0344: load the remaining group of grid structure samples 1 to failure.
[0111] Specifically, when the first group of grid structure samples 1 fails, the parameters of the first load and the second load at the time of failure are recorded, and the parameters are set as the failure load. When testing the remaining group of grid structure samples 1, the first load and the second load are first set to 2% of the preset load and, and the first load and the second load are loaded to the remaining group of grid structure samples 1, and then the first load and the second load are gradually increased. When the values of the first load and the second load are loaded to 80% of the failure load, the first load and the second load are set to gradually increase by 2% of the failure load, until the grid structure samples 1 fail.
[0112] In some embodiments of the present disclosure, referring to Figure 11 In step S04, the third load and the fourth load are applied to the grid structure samples 1 along the diagonal direction of the grid structure samples 1, and the third load and the fourth load are applied to the grid structure samples 1 along the normal direction of the grid structure samples 1, wherein the third load and the fourth load are the same in size and are loaded at the same time, which includes:
[0113] S041: set the maximum load of the fatigue test;
[0114] S042: apply the third load and the fourth load to the grid structure samples 1 multiple times;
[0115] S043: when the number of times of applying the third load and the fourth load exceeds 200,000 times, the third load and the fourth load are gradually increased.
[0116] Specifically, 50% of the preset load is set as the maximum load of the fatigue test, the third load and the fourth load are loaded on the grid structure typical piece 1 multiple times, and when the loading times on the grid structure typical piece 1 exceed 200,000 times, the maximum load of the fatigue test is gradually increased.
[0117] In some embodiments of the present disclosure, after the loading times of the third load and the fourth load exceed 200,000 times in step S043, the third load and the fourth load are gradually increased, which includes:
[0118] The third load and the fourth load are increased by 5% each time.
[0119] It can be understood that in the remaining embodiments, the third load and the fourth load are not limited to being increased by 5% each time, and the embodiments of the present disclosure do not limit this.
[0120] It should be noted that when the third load and the fourth load are loaded on the grid structure test piece, if the following phenomena occur, it indicates that the grid structure test piece has failed, and this needs to be recorded.
[0121] First, the grid test piece is damaged during the loading of the third load and the fourth load.
[0122] Second, the rigidity loss is 10%.
[0123] Third, abnormal noise occurs during the test.
[0124] In this embodiment, the test operation steps of the grid structure typical piece are shown in Table 1 as follows:
[0125] Table 1 Test operation steps of the grid structure typical piece
[0126]
[0127] Referring to Figure 13 , Figure 14 , the embodiments of the present disclosure also provide a grid structure typical piece compression-shear composite test device. Wherein, the test device includes a shearing mechanism 3 and a pressure applying mechanism 4, the shearing mechanism 3 is used to clamp the grid structure typical piece to apply a shearing force (for example, the first load and the third load) to the grid structure typical piece 1; the pressure applying mechanism 4 is used to apply a pressure perpendicular to the grid structure typical piece 1 (for example, the second load and the fourth load) to the grid structure typical piece 1.
[0128] Specifically, the shearing mechanism 3 comprises a shearing frame 33, two double-ear clamps 31 and a shearing cylinder 32; the two double-ear clamps 31 are arranged on the shearing frame 33 and form a clamping space for the grid structure test piece, and one of the double-ear clamps 31 is movably arranged on the shearing frame 33; the shearing cylinder 32 is connected with the double-ear clamp 31 arranged movably. When it is needed to apply a first load to the grid structure test piece 1, two corners (two corners arranged along the diagonal line) of the grid structure test piece 1 are clamped on the double-ear clamps 31 respectively, the shearing cylinder 32 is started, and the shearing cylinder 32 drives the double-ear clamp 31 arranged movably to move, so as to achieve the purpose of applying a shearing force to the grid structure test piece 1.
[0129] It can be understood that in the remaining embodiments, the two double-ear clamps 31 can be movably arranged on the shearing frame 33, and correspondingly, the shearing cylinder 32 needs to be arranged on each of the two double-ear clamps 31. Thus, when it is needed to apply a shearing force to the grid structure test piece 1, two corners (two corners arranged along the diagonal line) of the grid structure test piece 1 are clamped on the double-ear clamps 31 respectively, and the shearing cylinder 32 corresponding to each of the double-ear clamps 31 is started, and the shearing cylinder 32 drives the double-ear clamp 31 arranged movably to move, so as to achieve the purpose of applying a shearing force to the grid structure test piece 1.
[0130] The pressure applying mechanism 4 comprises a stopper 41, a steel wire rope 42, a connecting rod 43 and a pressure cylinder 44; the pressure cylinder 44 is installed on the shearing frame 33, the movement direction of the pressure cylinder 44 is perpendicular to the movement direction of the shearing cylinder 32, the stopper 41 is arranged on one side of the grid structure test piece 1 and connected with the piston rod of the pressure cylinder 44 through the steel wire rope 42. It can be understood that in the embodiment of the present disclosure, the grid structure test piece 1 is divided into multiple regions by the reinforcing ribs 11, in order to make the loads applied to each region of the grid structure test piece 1 uniform, multiple stoppers 41 can be arranged, the multiple stoppers 41 are connected with the connecting rod 43 through the steel wire rope 42, and the connecting rod 43 is connected with the pressure cylinder 44.
[0131] Figure 12 For applying pressure to the grid structure test piece, refer to Figure 12 When it is needed to apply pressure to the grid structure test piece 1, the pressure cylinder 44 is started, the movement of the pressure cylinder 44 drives the connecting rod 43 to move, the movement of the connecting rod 43 drives the multiple steel wire ropes 42 to move, and the multiple steel wire ropes 42 drive the stoppers 41 corresponding thereto to move, so as to achieve the purpose of applying uniform pressure to each region of the grid structure test piece 1.
[0132] Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the features disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
Claims
1. A method for compression-shear combined test of a representative member of a lattice structure, characterized by, The method comprises: providing a grid structure sample; mounting a detector on the grid structure sample; loading a first load on the grid structure sample along a diagonal direction of the grid structure sample; loading a second load on the grid structure sample along a normal direction of the grid structure sample, wherein the first load and the second load have the same magnitude and are loaded simultaneously; applying a plurality of third loads on the grid structure sample along the diagonal direction of the grid structure sample and a plurality of fourth loads on the grid structure sample along the normal direction of the grid structure sample, wherein the third loads and the fourth loads have the same magnitude and are loaded simultaneously; recording the number of times of loading the third loads and the fourth loads on the grid structure sample and parameters on the detector.
2. The method of claim 1, wherein, Mounting a detector on the grid structure sample comprises: mounting a plurality of strain gauges on the grid structure sample; dividing the grid structure sample into a plurality of detection areas; providing a pressure sensor at a center position of each detection area.
3. The method of claim 2, wherein the grid structure is a representative member of a grid structure. The strain gauges comprise a first sub-strain gauge, a second sub-strain gauge, a third sub-strain gauge and a fourth sub-strain gauge.
4. The method according to claim 3, wherein Mounting a plurality of strain gauges on the grid structure sample comprises: providing a grid hole with four sides, a first diagonal line and a second diagonal line; providing the first sub-strain gauge and the fourth sub-strain gauge at two end positions of the first diagonal line, and symmetrically arranging the first sub-strain gauge and the fourth sub-strain gauge with respect to the length direction of the second diagonal line; providing the second sub-strain gauge and the third sub-strain gauge at adjacent sides, connecting the second sub-strain gauge and the third sub-strain gauge, and symmetrically arranging the second sub-strain gauge and the third sub-strain gauge with respect to the second diagonal line.
5. The method of claim 1, wherein, Loading a first load on the grid structure sample along a diagonal direction of the grid structure sample and loading a second load on the grid structure sample along a normal direction of the grid structure sample, wherein the first load and the second load have the same magnitude and are loaded simultaneously, comprises: dividing the grid structure sample into a plurality of groups, wherein the plurality of groups of the grid structure sample comprise a first group of grid structure samples and a remaining group of grid structure samples; setting a preset load; loading the load on the first group of grid structure samples for testing; loading the load on the remaining group of grid structure samples for testing.
6. The method of claim 5, wherein the grid structure is a representative member of a grid structure. Loading the load on the first group of grid structure samples for testing comprises: setting ten percent of the preset load as a first initial load of the first load and the second load, gradually increasing the first load and the second load on the first group of grid structure samples, and repeating a plurality of times; setting five percent of the preset load as a second initial load of the first load and the second load, gradually increasing the first load and the second load on the first group of grid structure samples until the first group of grid structure samples is damaged.
7. The method of claim 6, wherein the grid structure is a representative member of a grid structure. Using 5% of the preset load as the second initial load for the first load and the second load, the first load and the second load are gradually increased onto the typical member of the first group of grid structures until the typical member of the first group of grid structures is damaged, including: When gradually increasing the first load and the second load to the typical component of the first group of grid structures, the rate of each load increase is 2 mm / min; the pause time for each load increase is 1 s.
8. The method of claim 6, wherein the grid structure is a representative member of a grid structure. The tests involving applying loads to the remaining typical members of the grid structure include: Record the destructive load of the first group of grid structure test specimens; Using five percent of the preset load as the second initial load for the first load and the second load, the first load and the second load are gradually increased to the remaining typical grid structure components; After the first load and the second load are applied to 80% of the destructive load, the remaining typical grid structure components are increased in increments of 2% of the destructive load. The remaining typical components of the grid structure are loaded to the point of failure.
9. The method of claim 5, wherein the grid structure is a representative member of a grid structure. Multiple third loads are applied to the typical grid structure along its diagonal direction, and multiple fourth loads are applied to the typical grid structure along its normal direction, wherein the third loads and the fourth loads are of the same magnitude and are applied simultaneously, including: Set the maximum load for the fatigue test; The third load and the fourth load are applied multiple times to the typical grid structure component; After the third load and the fourth load have been loaded more than 200,000 times, the third load and the fourth load are gradually increased.
10. The method of claim 9, wherein the grid structure is a representative member of a grid structure. After the third load and the fourth load have been applied more than 200,000 times, the third load and the fourth load are gradually increased. The third load and the fourth load include: The third load and the fourth load are increased by five percent each time.