Experimental device, system and method for transverse shear deformation of three-dimensional woven fabrics

Abstract

The present application provides an experimental device, an experimental system and an experimental method for transverse shear deformation of three-dimensional woven fabrics. The experimental device includes: a pressure module, including: a pressure sensor, configured to display the transverse pressure in real time; a pressure plate, one side of which is connected to the pressure sensor; a base, connected to the pressure plate, on which a first joint is arranged; a rotating feed component, passing through the base and arranged opposite to the pressure sensor, configured to apply transverse pressure to the pressure sensor through the rotating feed component; an adjustment module, including: an adjustment plate, connected to the base; a second joint, connected to the adjustment plate; a tightening module, which contacts the side of the adjustment plate away from the pressure plate and is detachably fixed to the base; the pressure plate and / or the adjustment plate slide along the base through the first guide component to adjust the distance between the two. The pressure sensor is combined with the rotating feed component to control the applied transverse pressure; the distance between the pressure plate and the adjustment plate is adjusted, which is suitable for specimens of different thicknesses.

Description

Technical Field

[0001] The present application relates to the field of material processing and forming processes, and in particular to an experimental device, an experimental system and an experimental method for transverse shear deformation of three-dimensional woven fabrics. Background Art

[0002] Three-dimensional woven composite structures are usually formed by continuous fiber reinforced composite materials. Due to the excellent specific strength and specific modulus of continuous fiber reinforced composite materials, their application in the aerospace field continues to increase, and they show a trend of transformation from secondary load-bearing structural parts to primary load-bearing structural parts, and from simple flat components to complex curved components. The main molding process for three-dimensional woven composite structures with complex geometric shapes is resin transfer molding (RTM). That is, first, a flat-plate-shaped continuous fiber reinforced composite material is preformed into a preform with a complex curved surface shape through a mold; then the resin is injected into a closed mold containing the preform, and after the resin is cured, a three-dimensional woven composite component with a complex curved surface (hereinafter referred to as three-dimensional woven fabric) is obtained. During the preforming stage, the three-dimensional woven fabric undergoes nonlinear large deformation behaviors such as in-plane shear, transverse shear, and transverse compression. At the same time, there are various couplings between these deformation behaviors, which have an important influence on the molding quality of the preform and the mechanical properties of the final composite component.

[0003] Since the thickness of three-dimensional woven fabrics is generally large, the transverse shear deformation during the preforming process is very obvious and cannot be ignored. At the same time, the three-dimensional woven fabric is affected by the transverse compression force, which will increase the fiber volume coefficient and further affect the transverse shear stiffness. Therefore, it is necessary to accurately characterize the coupling behavior of transverse compression and transverse shear. To this end, a special experimental device is required for the transverse compression and transverse shear coupling deformation of three-dimensional woven fabrics, so as to obtain the transverse shear behavior under different transverse pressure states, and then provide parameter input for preforming simulation. This is of great significance to improving the molding quality and strength of three-dimensional woven composite structures.

[0004] In the prior art, for the transverse shear deformation experiment of three-dimensional woven fabrics, one method is to use a simple transverse shear fixture, stick the three-dimensional woven fabric on the clamping plate of the fixture, and then stretch it with a test machine to achieve the transverse shear deformation of the three-dimensional woven fabric, and derive the parameters in the transverse shear strain energy function through the load-displacement curve. Another method is to use a guide rod to fix the fabric specimen on two parallel plates to ensure that the transverse pressure along the thickness direction is accurately applied during the installation of the specimen, and then apply pure shear strain to the specimen, and then establish a transverse shear strain energy density function based on the transverse shear strain. Another method is to use a transverse shear fixture, which releases the freedom of the specimen in the thickness direction to prevent errors caused by thinning of the specimen due to deformation such as yarn slippage during the transverse shear deformation process. Summary of the invention

[0005] In order to solve the problems existing in existing experimental devices, such as the uncontrollable magnitude of lateral pressure and the failure to consider the coupling mechanism between the lateral pressure and the three-dimensional woven fabric during the lateral shear deformation process, the present application aims to provide an experimental device, an experimental system and an experimental method for lateral shear deformation of three-dimensional woven fabrics.

[0006] According to a first exemplary embodiment of the present application, an experimental device for transverse shear deformation of three-dimensional woven fabrics comprises:

[0007] Pressure module, including:

[0008] a pressure sensor configured to display lateral pressure in real time;

[0009] A pressure plate, one side of which is connected to the pressure sensor;

[0010] A base, connected to the pressure plate, on which a first joint is arranged;

[0011] a rotary feed component, passing through the base and disposed opposite to the pressure sensor, and configured to apply the lateral pressure to the pressure sensor through the rotary feed component;

[0012] Adjustment module, including:

[0013] An adjustment plate connected to the base;

[0014] A second joint connected to the adjustment plate;

[0015] A tightening module, which contacts the side of the adjustment plate away from the pressure plate and is detachably fixed to the base;

[0016] The pressure plate and / or the adjustment plate slide along the base through the first guide component so as to adjust the distance between the two.

[0017] According to some embodiments of the present application, the base includes:

[0018] a horizontal base, on which a second guide component is disposed to cooperate with the first guide component;

[0019] A vertical base is vertically connected to the horizontal base, and a threaded guide column is arranged on the vertical base, and the rotary feeding component passes through the threaded guide column.

[0020] According to some embodiments of the present application, the threads on the threaded guide pin have a self-locking property.

[0021] According to some embodiments of the present application, the tightening module includes:

[0022] a top plate in contact with a side of the adjustment plate facing away from the pressure plate;

[0023] The connecting seat is connected to the top plate, is sleeved on the horizontal base and can move along the horizontal base.

[0024] According to some embodiments of the present application, the experimental device further includes:

[0025] The third guiding component is connected between the pressure plate and the top plate.

[0026] According to some embodiments of the present application, the first guiding component includes a guiding platform; the second guiding component includes a guiding groove; and the third guiding component includes a guiding rod.

[0027] According to some embodiments of the present application, the adjustment plate includes:

[0028] A slide groove, wherein the second joint is connected to the adjustment plate through the slide groove and can adjust its position along the slide groove.

[0029] According to some embodiments of the present application, the first guide component and the second guide component of the pressure plate are clearance-matched.

[0030] According to another aspect of the present application, there is also provided an experimental system for transverse shear deformation of three-dimensional woven fabrics, comprising:

[0031] Tensile testing machine;

[0032] The above experimental device is fixed to the tensile machine via the first joint;

[0033] The tensile machine applies tensile force to the adjustment plate through the second joint, and keeps the axis of the tensile machine on the central axis plane of the three-dimensional woven fabric.

[0034] According to another aspect of the present application, there is also provided an experimental method for transverse shear deformation of three-dimensional woven fabrics, using the above-mentioned experimental system, the experimental method comprising:

[0035] Fixing the three-dimensional woven fabric to the inner side of the adjustment plate, rotating the rotary feeding component to press the pressure plate against the other side of the three-dimensional woven fabric;

[0036] Adjusting the positions of the adjusting plate, the top plate and the pressure plate to ensure that the axis of the tensile machine is within the central axis plane of the three-dimensional woven fabric;

[0037] According to the value of the pressure sensor, adjusting the rotary feed component to apply a stable lateral pressure;

[0038] The tensile machine applies a tensile force to the adjustment plate through the second joint, and the three-dimensional woven fabric undergoes shear deformation as the adjustment plate moves;

[0039] A correlation curve between the tensile force and the shear deformation and the applied lateral pressure are output.

[0040] The experimental device for lateral shear deformation of three-dimensional woven fabrics provided by the present application can apply lateral pressure in the thickness direction of the three-dimensional woven fabric with a simple rotation, and the pressure operation is simple; the real-time display of the pressure sensor is combined with the rotating feed component to control the applied lateral pressure; the pressure sensor is rotated according to the indication, and the pressure application process is more intuitive; the thread connecting the rotating feed component on the base has a self-locking characteristic, which can prevent the rotating feed component from rotating due to the reaction force at the test piece, and avoid inaccurate lateral pressure. By adjusting the distance between the pressure plate and the adjustment plate, it can be applied to test pieces of different thicknesses. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without exceeding the scope of protection required by the present application.

[0042] Figure 1 A schematic diagram of an experimental device for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown;

[0043] Figure 2 A schematic diagram of an experimental device after clamping a three-dimensional woven fabric specimen according to an exemplary embodiment of the present application is shown;

[0044] Figure 3 A schematic diagram of a pressure applying module according to an exemplary embodiment of the present application is shown;

[0045] Figure 4 A schematic diagram of a base according to an exemplary embodiment of the present application is shown;

[0046] Figure 5 A schematic diagram of an adjustment module according to an exemplary embodiment of the present application is shown;

[0047] Figure 6 A schematic diagram of fixing a three-dimensional woven fabric according to an exemplary embodiment of the present application is shown;

[0048] Figure 7 A schematic diagram of a tightening module according to an exemplary embodiment of the present application is shown;

[0049] Figure 8 A schematic diagram of an experimental system for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown;

[0050] Fig. 9 A schematic diagram of an experiment principle according to an exemplary embodiment of the present application is shown;

[0051] Fig.10 The experimental method flow for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown;

[0052] Fig.11 A schematic diagram of the coupling mechanism between transverse shear deformation and transverse pressure of a three-dimensional woven fabric according to an exemplary embodiment of the present application is shown. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0054] The terms "first", "second", etc. of the present application are used to distinguish different objects, rather than to describe a predetermined order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0055] Reference to "embodiment" herein means that the predetermined features, structures, or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0056] The inventors have found that, for transverse shear experiments on three-dimensional woven fabrics, the existing experimental devices cannot control the magnitude of the transverse pressure, and thus cannot obtain the effect of transverse compression deformation on transverse shear deformation; on the other hand, it is impossible to obtain relevant data on the coupling mechanism between the three-dimensional woven fabric and the transverse pressure during the transverse shear deformation process. In order to solve the above problems existing in the existing experimental devices, the present application provides an experimental device, an experimental system and an experimental method for transverse shear experiments on three-dimensional woven fabrics, which can achieve controllable transverse pressure through simple operations, and can obtain transverse shear deformation behaviors under different transverse pressure states, thereby providing a more accurate strain energy function and constitutive model for exploring the transverse compression-transverse shear coupling deformation of three-dimensional woven fabrics, and further more accurately predicting the deformation behavior of three-dimensional woven fabrics during the preforming process.

[0057] The technical solution of the present application will be described in detail below with reference to the accompanying drawings.

[0058] Figure 1 A schematic diagram of an experimental device for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown; Figure 2 A schematic diagram of an experimental device after clamping a three-dimensional woven fabric specimen according to an exemplary embodiment of the present application is shown.

[0059] like Figure 1 and Figure 2 As shown, the experimental device 1000 for lateral shear deformation of three-dimensional woven fabrics provided by the present application includes: a pressure module 100, an adjustment module 200 and a tightening module 300. During the experiment, a specimen 400 of the three-dimensional woven fabric is fixed between the pressure module 100 and the adjustment module 200. According to some embodiments of the present application, the three-dimensional woven fabric specimen can be fixed by bonding, which is not limited by the present application.

[0060] The pressure module 100 is used to apply transverse pressure to the thickness direction of the three-dimensional woven fabric specimen. The pressure module 100 includes a base 110, a pressure plate 120, and a rotary feeding component 130. Figure 1, the base 110 is connected to the pressure plate 120. A first joint 113 is provided on the base 110, which is located at the horizontal center of the base 110. Its function is to be connected to the connecting joint of the tensile machine, and the experimental device is fixed on the tensile machine, which can ensure the position of the experimental device 1000 in the tensile machine. The rotary feed component 130 passes through the base 110, and the base 110 supports the rotary feed component 130. By rotating the rotary feed component 130, lateral pressure can be applied to the pressure plate 120. A pressure sensor 121 is provided on the pressure plate 120 for real-time display of lateral pressure. One side of the pressure plate 120 is connected to the pressure sensor 121. The rotary feed component 130 passes through the base 110 and is arranged opposite to the pressure sensor 121. Lateral pressure can be applied to the pressure sensor 121 through the rotary feed component 130. The real-time display of the pressure sensor 121 is combined with the rotary feed component 130, so that the applied lateral pressure can be controlled by simple operation.

[0061] The adjustment module 200 includes an adjustment plate 210 and a second joint 220. The adjustment plate 210 cooperates with the pressure plate 120 of the pressure module 100 to fix the three-dimensional woven fabric specimen in the thickness direction. The second joint 220 is connected to the adjustment plate 210. An external tensile machine applies tension to the adjustment plate 210 through the second joint 220, driving the adjustment plate 210 to move upward, thereby causing shear deformation of the three-dimensional woven fabric fixed between the adjustment plate 210 and the pressure plate 120. The adjustment plate 210 is connected to the base 110, and the base 110 supports the adjustment plate 210. The pressure plate 120 and / or the adjustment plate 210 can be guided by a first guide component (see Figure 2 and Figure 4 and related descriptions) slide along the base 110 to adjust the distance between the two. Further, by adjusting the distance between the pressure plate 120 and the adjustment plate 210, the experimental device 1000 can be applied to three-dimensional woven fabric specimens of different thicknesses.

[0062] The tightening module 300 contacts the side of the adjusting plate 210 away from the pressure plate 120 and is detachably fixed to the base 110. For example, after the position is determined, it is fixedly connected to the base 110 by screws 350. Its function is to balance the torque transmitted to the adjusting plate 210 by the pressure applied by the pressure plate 120 in the thickness direction of the three-dimensional woven fabric. Figure 1 A third guide component 140 may be provided between the pressing module 300 and the pressure plate 120 to ensure that a transverse pressure along the thickness direction of the test piece is accurately applied during the test piece installation process. According to an exemplary embodiment of the present application, the third guide component may be a set of guide rods 140 .

[0063] Figure 3 A schematic diagram of a pressure applying module according to an exemplary embodiment of the present application is shown; Figure 4 A schematic diagram of a base according to an exemplary embodiment of the present application is shown.

[0064] As mentioned above, the pressure module 100 includes a base 110, a pressure plate 120, and a rotary feeding component 130. Figure 3 The base 110 includes a horizontal base 111 and a vertical base 112 vertically connected thereto. The horizontal base 111 is used to provide support for the pressure plate 120, and the vertical base 112 is used to provide support for the rotary feed component 130. When the experimental device is fixed on the tensile machine, the first joint located at the center of the horizontal base 111 can ensure the centering position of the experimental device on the tensile machine. A second guide component 114 is provided on the horizontal base 111. According to an exemplary embodiment of the present application, the second guide component 114 can be a set of guide grooves (such as sliding grooves). Through the sliding grooves, the positions of the pressure plate 120 and the adjustment plate for fixing the three-dimensional woven fabric can be adjusted, so as to be suitable for transverse shear tests of three-dimensional woven fabrics of different thicknesses. A threaded guide column 115 can also be provided on the vertical base 112. The rotary feed component 130 passes through the threaded guide column 115, which supports the rotary feed component 130, thereby ensuring the structural stability of the experimental device. According to other embodiments of the present application, the threaded guide pin 115 may adopt a thread with self-locking characteristics. The self-locking characteristics of the thread can prevent the rotary feed component 130 from self-rotating due to the reaction force at the test piece, thereby avoiding inaccurate lateral pressure.

[0065] See also Figure 3 , the pressure plate 120 is connected to the horizontal base 111 through the first guide component 123. The first guide component 123 cooperates with the second guide component 114. According to an exemplary embodiment of the present application, the first guide component 123 may be a group of guide platforms (e.g., bosses). Through the cooperation of the bosses and the sliding grooves, the pressure plate 120 can slide along the horizontal base 111, thereby adjusting the position. According to some embodiments of the present application, the first guide component 123 of the pressure plate 120 and the second guide component 114 of the horizontal base 111 may adopt a clearance fit. The clearance fit can ensure the verticality of the pressure plate when applying lateral pressure to the thickness direction of the specimen. According to some embodiments of the application, a group of lugs with through holes may be provided on both sides of the pressure plate. The third guide component 114 is connected to the top tightening module through the through holes on the lugs. According to some embodiments of the present application, the third guide part 114 may be a group of guide rods. By providing the guide rods, it can be ensured that the lateral pressure along the thickness direction of the specimen is accurately applied during the installation of the specimen.

[0066] like Figure 3As shown, the rotary feed component 130 may be provided with a handle 131, which is convenient for the experimenter to operate. The rotary feed component 130 may also be provided with a baffle 132, which is used to limit the feed amount of the rotary feed component 130 to avoid damage to the test piece and the test device due to excessive feed amount. The rotary handle 130 and the threaded guide column on the base are threadedly matched to realize rotary feeding, thereby applying pressure to the pressure sensor 121. After the rotary handle 130 passes through the threaded guide column 115, it can contact and apply pressure to the pressure sensor 121 through the sensor protection sheet 122 (for example, a gasket), thereby protecting the pressure sensor from being damaged by the rotary handle and making the pressure indication more stable. The size of the lateral pressure can be determined according to the indication of the pressure sensor 121, and the applied lateral pressure can be controlled by adjusting the feed of the rotary handle 130.

[0067] Figure 5 A schematic diagram of an adjustment module according to an exemplary embodiment of the present application is shown; Figure 6 A schematic diagram of fixing a three-dimensional woven fabric according to an exemplary embodiment of the present application is shown.

[0068] As mentioned above, the adjustment module 200 includes an adjustment plate 210 and a second joint 220. According to some embodiments of the present application, a guide component 211 (e.g., a guide platform) may be provided at one end of the adjustment plate 210 connected to the horizontal base, which cooperates with the sliding groove on the horizontal base and can slide along the sliding groove to adjust the position. Figure 5 , the adjustment plate 210 is connected to the second joint 220 through the connecting plate 230. A slide groove 260 is provided on the connecting plate 230, and the second joint 220 is connected to the adjustment plate 210 through the slide groove 260, and can adjust the position along the slide groove 260. According to some embodiments of the present application, the shape of the slide groove 260 can be rectangular, and the present application does not limit this. The rectangular slide groove can ensure that during the experiment, the axis of the tensile machine is on the central axis plane of the three-dimensional woven fabrics of different thicknesses, thereby avoiding errors in the test piece due to the influence of the moment during the transverse shearing process.

[0069] During the experiment, the three-dimensional woven fabric specimens were fixed and installed as follows: Figure 6 As shown. After the three-dimensional woven fabric specimen is pasted on the adjustment plate 210, it can be moved along the rectangular slide groove to adjust the distance between it and the pressure plate 120 to adapt to specimens of different thicknesses. The pressure plate 120 is pushed toward the adjustment plate 210 under the pressure applied by the rotating feed component, so that the three-dimensional woven fabric specimen is bonded and fixed between the adjustment plate 210 and the pressure plate 120. The position of the adjustment plate 210 is fixed by tightening the adjustment nut 250 at the connection between the second joint and the slide groove 260 and pressing the gasket 240. At this point, the fixation of the three-dimensional woven fabric specimen is completed. Subsequently, pressure in the thickness direction can be applied to the three-dimensional woven fabric specimen by rotating the handle, so as to experiment the transverse shear deformation behavior of the three-dimensional woven fabric under different pressure states.

[0070] Figure 7 A schematic diagram of a tightening module according to an exemplary embodiment of the present application is shown.

[0071] See also Figure 7 , the tightening module 300 includes a top plate 310 and a connecting seat 320 connected thereto. After assembly, the top plate 310 contacts the side of the adjustment plate away from the pressure plate, and its function is to balance the torque transmitted to the adjustment plate by the pressure applied by the pressure plate in the thickness direction of the specimen. The connecting seat 320 can be ringed on the horizontal base and can move along the horizontal base to cooperate with the position adjustment of the adjustment plate. After the position is adjusted, the position of the tightening module 300 on the horizontal base is fixed by tightening the fixing bolts 350, so as to ensure that no excess torque is generated during the lateral shearing process. A group of lugs 330 with through holes can be set on both sides of the top plate 310, and the guide rod of the pressure module can pass through the lugs on the pressure and the lugs 330 on the top plate 310 in turn, so as to be connected between the pressure plate and the top plate 310.

[0072] Figure 8 A schematic diagram of an experimental system for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown; Fig. 9 A schematic diagram of an experimental principle according to an exemplary embodiment of the present application is shown.

[0073] According to another aspect of the present application, an experimental system 3000 for transverse shear deformation of three-dimensional woven fabrics is also provided. Figure 8 , the experimental system 3000 includes the above-mentioned experimental device 1000 and a tensile machine 2000. The experimental device 1000 is fixed to the tensile machine through the first joint 113. The tensile machine 2000 applies tension to the adjustment plate 210 through the second joint 220 of the experimental device 1000 to perform a transverse shear deformation experiment, and in this process, the axis of the tensile machine 2000 is kept on the central axis plane of the three-dimensional woven fabric specimen. According to the exemplary embodiment of the present application, the tensile machine can be an electronic universal testing machine, or other testing machines that can provide tensile force, and the present application does not limit this.

[0074] During the experiment, the three-dimensional woven fabric specimen can be pasted and installed at the center position of the adjustment plate 210; glue is applied to the working area of ​​the pressure plate 120, and then under the thrust of the rotating feed component 130, the pressure plate 120 approaches and presses the three-dimensional woven fabric along the guide rod 140. By adjusting the position of the adjustment plate 210, the axis of the electronic universal testing machine can be ensured to be within the central axis plane of the specimen. In the process of applying lateral pressure, the lateral pressure applied to the three-dimensional woven fabric can be determined by the pressure sensor 121. After the positions of the adjustment plate 210 and the top plate 310 are adjusted and fixed, the feed component is rotated to control the indication of the pressure sensor 121 to be twice the pressure required for the experiment, that is, the pressure between the top plate 310 and the adjustment plate 210 is equal to the lateral pressure required for the experiment. The adjustment plate 210 moves upward relative to the pressure plate 120 driven by the clamp of the electronic universal testing machine 2000, and the force of the three-dimensional woven fabric in the shear deformation process under the action of lateral pressure can be recorded by the electronic universal testing machine 2000.

[0075] Fig. 9 (a) shows the stress state of the three-dimensional woven fabric specimen during the experiment. Fig. 9 (b) shows the stress state of the adjustment plate 210. During the transverse shearing process of the three-dimensional woven fabric specimen 400, the fibers in the thickness direction of the three-dimensional woven fabric specimen 400 will stretch as the adjustment plate 210 moves upward, generating a tensile force F along the thickness fiber direction. L The transverse shear angle θ can be obtained according to the following formula (1), where x is the vertical displacement of the adjustment plate 210, and t is the thickness of the three-dimensional woven fabric specimen 400. However, since the transverse shear angle θ is generally small and the tensile stiffness along the thickness direction is low, the tensile force F in the thickness direction caused by the transverse shear angle θ is L is small and can therefore be ignored.

[0076] Taking the adjustment plate 210 as an example, its main forces are shown in the figure: The vertical forces include: the tension F provided by the electronic universal testing machine, the friction F between the top plate and the adjustment plate 210 f , 3D woven fabric specimen 400 thickness direction fiber tensile force F L , the transverse shear force F between the three-dimensional woven fabric specimen 400 and the adjustment plate 210 S ; Horizontal forces include: lateral pressure F N , the pressure F between the three-dimensional woven fabric specimen 400 and the adjustment plate 210 C With respect to the friction force between the top plate and the adjusting plate 210, the friction coefficient μ between the top plate and the adjusting plate 210 can be determined by the existing measurement method. According to the load F output by the electronic universal testing machine and formula (2), the shear force F acting on the three-dimensional woven fabric specimen 400 can be obtained: S .

[0077]

[0078] F S =FF L sinθ-μF N (2)

[0079] Fig.10 The experimental method flow for transverse shear deformation of three-dimensional woven fabrics according to an exemplary embodiment of the present application is shown; Fig.11 A schematic diagram of the coupling mechanism between transverse shear deformation and transverse pressure of a three-dimensional woven fabric according to an exemplary embodiment of the present application is shown.

[0080] According to another aspect of the present application, there is also provided an experimental method for transverse shear deformation of three-dimensional woven fabrics, see Fig.10 , the experimental method includes the following steps.

[0081] Step S110, fix the three-dimensional woven fabric to the inner side of the adjustment plate, rotate the rotary feeding component to press the pressure plate against the other side of the three-dimensional woven fabric. Before the experiment is carried out, first fix the three-dimensional woven fabric specimen on the experimental device. For example, the three-dimensional woven fabric specimen is pasted on the inner side of the glue-coated adjustment plate, and after installing two guide rods, the rotary feeding component is manually fed to press the other side of the three-dimensional woven fabric specimen against the glue-coated pressure plate. In this way, the three-dimensional woven fabric is fixed.

[0082] Step S120, adjusting the positions of the adjusting plate, the top plate and the pressure plate to ensure that the axis of the tensile machine is within the center axis plane of the three-dimensional woven fabric. After the three-dimensional woven fabric specimen is fixed, the positions of the adjusting plate, the top plate and the pressure plate can be adjusted as needed to ensure that the axis of the tensile machine is within the center axis plane of the three-dimensional woven fabric.

[0083] Step S130, according to the value of the pressure sensor, adjust the rotary feed component to apply a stable lateral pressure. By rotating the rotary feed component and controlling the applied lateral pressure according to the value displayed by the pressure sensor. After the reading of the pressure sensor is stable, tighten the fixing bolt to fix the position of the top plate. At this point, the application of lateral pressure to the three-dimensional woven fabric is completed.

[0084] Step S140, the tensile machine applies tensile force to the adjustment plate through the second joint, and the three-dimensional woven fabric undergoes shear deformation as the adjustment plate moves. The load of the tensile machine is adjusted to zero, and the tensile machine can be set to a tensile speed of 2mm / min to start the transverse shear test.

[0085] Step S150: outputting the correlation curve between the tensile force and the shear deformation and the applied lateral pressure. Fig.11 As shown, different lateral pressures F N1 、FN2 、F N3 The load F S Correlation curve between displacement x, where F N1 <F N2 <F N3 , F N1 = 0. The load-displacement curve under transverse pressure can accurately characterize the coupling behavior of transverse compression and transverse shear, and then explore the transverse shear behavior under different transverse pressure states, providing parameter input for three-dimensional woven fabric preforming simulation.

[0086] The experimental device for transverse shear deformation of three-dimensional woven fabrics provided in the present application can apply transverse pressure in the thickness direction of the three-dimensional woven fabric with only a simple rotation, and the pressure application operation is simple; the applied lateral pressure is controlled by combining the real-time display of the pressure sensor with the rotating feed component; the pressure is rotated according to the indication of the pressure sensor, and the pressure application process is more intuitive; the thread on the base connected to the rotating feed component has a self-locking characteristic, which can prevent the rotating feed component from rotating due to the reaction force at the test piece, thereby avoiding inaccurate lateral pressure.

[0087] The experimental device for lateral shear deformation of three-dimensional woven fabrics provided in the present application can be applied to test pieces of different thicknesses by adjusting the distance between the pressure plate and the adjustment plate. The characterization accuracy of the shear force of the three-dimensional woven fabric is related to the installation accuracy between the experimental device and the tensile machine. During the experiment, by adjusting the slide groove set by the module, it can be ensured that the axis of the tensile machine is always in the central axis plane of the three-dimensional woven fabric, and the installation accuracy and centration are easy to ensure, thereby avoiding the three-dimensional woven fabric from being subjected to torque and avoiding shear force errors caused by uneven force.

[0088] The embodiments of the present application are described in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and its core idea of ​​the present application. At the same time, changes or deformations made by those skilled in the art based on the ideas of the present application, the specific implementation methods and the scope of application of the present application, all belong to the scope of protection of the present application. In summary, the content of this specification should not be construed as a limitation on the present application.

Claims

1. Experimental device for transverse shear deformation of three-dimensional woven fabrics, characterized in that: include: Pressure module, including: a pressure sensor configured to display lateral pressure in real time; A pressure plate, one side of which is connected to the pressure sensor; A base connected to the pressure plate, on which a first joint is arranged, wherein the base comprises a horizontal base and a vertical base, the vertical base is connected to the horizontal base, a threaded guide column is arranged on the vertical base, and the thread on the threaded guide column has a self-locking property; a rotary feed component, passing through the threaded guide column and disposed opposite to the pressure sensor, and configured to apply the lateral pressure to the pressure sensor through the rotary feed component; Regulation module, including: An adjustment plate connected to the base, the adjustment plate comprising a slide groove; A second joint, connected to the adjustment plate through the slide groove and capable of adjusting a position along the slide groove; A tightening module is in contact with a side of the adjustment plate away from the pressure plate and is detachably fixed to the base, wherein the tightening module includes: a top plate in contact with a side of the adjustment plate facing away from the pressure plate; and A connecting seat, connected to the top plate, sleeved on the horizontal base and capable of moving along the horizontal base; The pressure plate and / or the adjustment plate slide along the base through a first guide component to adjust the distance between the two, and a second guide component is arranged on the horizontal base, and the second guide component is clearance-matched with the first guide component; the experimental device further comprises a third guide component, and the third guide component is connected between the pressure plate and the top plate; the first guide component comprises a guide platform, the second guide component comprises a guide groove, and the third guide component comprises a guide rod; The first joint is located at the horizontal center of the base, and is used to connect to the connecting joint of an external tensile testing machine to fix the experimental device on the tensile testing machine, thereby ensuring the position neutrality of the experimental device in the tensile testing machine; the external tensile testing machine applies tension to the adjustment plate through the second joint, driving the adjustment plate to move upward, thereby causing shear deformation of the three-dimensional woven fabric fixed between the adjustment plate and the pressure plate.

2. An experimental system for transverse shear deformation of three-dimensional woven fabrics, comprising: Tensile testing machine; The experimental device according to claim 1 is fixed to the tensile machine via the first joint; The tensile machine applies tensile force to the adjustment plate through the second joint, and keeps the axis of the tensile machine on the central axis plane of the three-dimensional woven fabric.

3. An experimental method for transverse shear deformation of three-dimensional woven fabrics, characterized in that: Using the experimental system described in claim 2, the experimental method comprises: Fixing the three-dimensional woven fabric to the inner side of the adjustment plate, rotating the rotary feeding component to press the pressure plate against the other side of the three-dimensional woven fabric; Adjusting the positions of the adjusting plate, the top plate and the pressure plate to ensure that the axis of the tensile machine is within the central axis plane of the three-dimensional woven fabric; According to the value of the pressure sensor, adjusting the rotary feed component to apply a stable lateral pressure; The tensile machine applies a tensile force to the adjustment plate through the second joint, and the three-dimensional woven fabric undergoes shear deformation as the adjustment plate moves; A correlation curve between the tensile force and the shear deformation and the applied lateral pressure are output.

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