Fabric vibration isolator and preparation method thereof

Abstract

The invention relates to the technical field of textile vibration isolation, and particularly discloses a preparation method of a fabric vibration isolator and the fabric vibration isolators, and the preparation method comprises the following steps: constructing a bending crease model according to vibration isolation characteristics of a target fabric vibration isolator; finite element analysis is conducted on the bending crease model, and preset fabric material attributes are given to the bending crease model; carrying out compression simulation on the bending crease model endowed with the preset fabric material attributes to obtain a compression force and displacement relationship of the bending crease model; determining a rigidity adjusting relation of the bending crease model according to the relation between the compression force and the displacement; constructing a quasi-zero stiffness crease pattern according to the bending crease model and the corresponding stiffness adjustment relation; and constructing a corresponding fabric three-dimensional unit according to the quasi-zero stiffness crease pattern to obtain the target fabric vibration isolator. According to the preparation method of the fabric vibration isolator, the problem that a linear vibration isolator is poor in vibration isolation capacity at low frequency can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of textile vibration isolation, and in particular to a preparation method of a fabric vibration isolator and the fabric vibration isolator. Background Art

[0002] Vibration is a widespread phenomenon in industry and life. Its improper or excessive use may lead to many kinds of hazards. Avoiding or controlling vibration has important practical significance in industry and society. By reducing the damage caused by vibration to equipment, the service life of equipment can be extended. Currently, commonly used linear isolators include spring isolators, airbag isolators and elastomer isolators. Their stiffness characteristics and damping characteristics remain linear or approximately linear within the working range, which means that the relationship between the external force on the isolator and its displacement satisfies a linear relationship. These types of isolators can only effectively isolate vibrations above their natural frequency, and have poor isolation capabilities for low-frequency vibrations; resonance peaks are prone to occur near the natural frequency, resulting in amplitude amplification; linear isolators cannot actively adjust stiffness and damping to adapt to changing excitation conditions.

[0003] Therefore, how to solve the problem that the linear vibration isolators in the prior art have poor vibration isolation capabilities at low frequencies has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0004] The present invention provides a method for preparing a fabric vibration isolator and the fabric vibration isolator, which solves the problem in the related art that the linear vibration isolator has poor vibration isolation capability at low frequencies.

[0005] As a first aspect of the present invention, a method for preparing a fabric vibration isolator is provided, comprising:

[0006] A bending crease model is constructed according to the vibration isolation characteristics of the target fabric isolator;

[0007] Performing finite element analysis on the bending crease model, and assigning preset fabric material properties to the bending crease model;

[0008] A compression simulation is performed on a bending crease model with preset fabric material properties to obtain the relationship between the compression force and displacement of the bending crease model;

[0009] Determining the stiffness adjustment relationship of the bending crease model according to the relationship between the compression force and the displacement;

[0010] Constructing a quasi-zero stiffness crease pattern according to the bending crease model and its corresponding stiffness adjustment relationship;

[0011] The corresponding three-dimensional fabric unit is constructed according to the quasi-zero stiffness crease pattern to obtain a target fabric vibration isolator.

[0012] Furthermore, a bending crease model is constructed according to the vibration isolation characteristics of the target fabric vibration isolator, including:

[0013] Determining parameter information of the arc according to the vibration isolation characteristics of the target fabric vibration isolator;

[0014] Create two arcs located in two identical planes according to the arc parameter information;

[0015] Extend two identical arcs respectively to obtain two surfaces spliced ​​at a preset angle;

[0016] The excess parts outside the two spliced ​​surfaces are cut off to obtain the bending crease model.

[0017] Furthermore, two identical arcs are extended respectively to obtain two curved surfaces spliced ​​at a preset angle, including:

[0018] Stretching the arc located in the first plane in a direction perpendicular to the first plane to obtain a first curved surface;

[0019] The arc located in the second plane is stretched to be formed into the first curved surface to obtain a second curved surface, and the second curved surface is spliced ​​with the first curved surface at a preset angle.

[0020] Furthermore, a compression simulation is performed on the bending crease model given the preset fabric material properties to obtain the compression force and displacement relationship of the bending crease model, including:

[0021] The compression state of the bending crease model is constructed according to the preset fabric material properties assigned by the bending crease model to simulate the force value when the bending crease model is compressed;

[0022] The physical parameter information of the bending crease model is changed to simulate the force state of the bending crease model when it is compressed under different physical parameters, and the relationship between the compression force and displacement of the bending crease model is obtained.

[0023] Further, the stiffness adjustment relationship of the bending crease model is determined according to the relationship between the compression force and the displacement, including:

[0024] Determining the stiffness characteristics of the bending crease model according to the relationship between the compression force and the displacement;

[0025] The stiffness adjustment relationship of the bending crease model is determined according to the stiffness characteristics of the bending crease model.

[0026] Furthermore, constructing a corresponding three-dimensional fabric unit according to the quasi-zero stiffness crease pattern includes:

[0027] Select fabric swatches;

[0028] Marking the fabric sample according to the quasi-zero stiffness crease pattern, and marking creases and folding lines on the fabric sample;

[0029] The three-dimensional fabric unit is constructed by folding and sewing.

[0030] Furthermore, the method for preparing the fabric vibration isolator further comprises:

[0031] Performing a compression test on the three-dimensional unit model with the bending crease to verify the quasi-zero stiffness characteristic of the three-dimensional unit model with the bending crease;

[0032] An isolation vibration experiment is performed on the fabric three-dimensional unit to verify the vibration isolation performance of the fabric three-dimensional unit.

[0033] Furthermore, the method for preparing the fabric vibration isolator further comprises, before the step of performing finite element analysis on the bending crease model:

[0034] Obtain the preset fabric material properties.

[0035] Further, obtaining the preset fabric material properties includes:

[0036] The preset fabric material is subjected to tensile, compression, shear, bending, hardness and fatigue experimental tests to obtain the physical and mechanical performance parameters of the preset fabric.

[0037] As another aspect of the present invention, a fabric vibration isolator is provided, which includes: a fabric vibration isolator prepared according to the method for preparing the fabric vibration isolator described above.

[0038] The preparation method of the fabric vibration isolator provided by the present invention starts from the bending and folding forms of the fabric, and constructs a bending crease model by combining the two forms of the fabric bending and folding, giving material properties to the fabric raw material, inputting boundary conditions into the established bending crease model, constructing it into a compression state, and revealing the principle that the stiffness of the crease model is adjustable; constructing a fabric three-dimensional unit based on the bending crease model, the fabric vibration isolator prepared by the preparation method of the fabric vibration isolator can make up for the disadvantage of the poor vibration isolation ability of the linear vibration isolator at low frequency, and at the same time has good load-bearing capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0040] Figure 1 The present invention provides a flow chart of a method for preparing a fabric vibration isolator.

[0041] Figure 2A flow chart for constructing a bending crease model provided by the present invention.

[0042] Figure 3 A flow chart of compression simulation of a bending crease model provided by the present invention.

[0043] Figure 4 A flow chart for determining the stiffness adjustment relationship of a bending crease model provided by the present invention.

[0044] Figure 5 A flow chart of constructing a fabric three-dimensional unit provided by the present invention.

[0045] Figure 6 A schematic diagram of the preparation process of the bending crease model provided by the present invention.

[0046] Figure 7 This is a schematic diagram of setting the finite element simulation conditions provided by the present invention.

[0047] Figure 8a A schematic diagram showing different stiffness curves for different chord heights h provided by the present invention.

[0048] Figure 8b A schematic diagram showing different stiffness curves at different angles β provided by the present invention.

[0049] Fig. 9 A schematic diagram of the stiffness curve results of experimental verification of the curved crease fabric provided by the present invention.

[0050] Fig.10a A schematic diagram of a crease design pattern based on a quasi-zero stiffness curve provided by the present invention.

[0051] Fig.10b A schematic diagram of a crease design pattern based on a positive stiffness curve provided by the present invention.

[0052] Fig.11 Schematic diagram of the load, constraint and mesh settings provided by the present invention.

[0053] Fig.12 This is a schematic diagram of the comparison curve between the compression force-displacement experiment and the model of the fabric three-dimensional unit provided by the present invention.

[0054] Fig.13a A schematic diagram of the amplitude-time response of the quasi-zero stiffness fabric unit array provided by the present invention.

[0055] Fig.13b A schematic diagram of the amplitude-time response of the positive stiffness fabric unit array provided by the present invention.

[0056] Fig.14 A schematic diagram of the vibration transmissibility of fabric unit arrays with different stiffness provided by the present invention. DETAILED DESCRIPTION

[0057] 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. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0058] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0059] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. 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 necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0060] In this embodiment, a method for preparing a fabric vibration isolator is provided. Figure 1 is a flow chart of a method for preparing a fabric vibration isolator according to an embodiment of the present invention. Figure 1 As shown, including:

[0061] S100, constructing a bending crease model according to the vibration isolation characteristics of the target fabric vibration isolator;

[0062] In an embodiment of the present invention, a bending crease model is constructed, which is specifically composed of two forms of bending and folding of the fabric. Two identical arcs are created in Solidworks and extended to obtain a curved surface. The two curved surfaces are spliced ​​at a certain angle, and the excess parts are cut to obtain the bending crease model.

[0063] S200, performing finite element analysis on the bending crease model, and assigning preset fabric material properties to the bending crease model;

[0064] In the embodiment of the present invention, finite element analysis is performed on the bending crease model, preset fabric material properties are assigned to the bending crease model, and geometric specifications and various material parameters of the fabric are obtained through experimental testing.

[0065] Specifically, the preset fabric material may be a twill denim material. It should be understood that the specific implementation form of the fabric material can be set according to user needs and is not limited here.

[0066] S300, performing compression simulation on a bending crease model with preset fabric material properties to obtain a relationship between compression force and displacement of the bending crease model;

[0067] In an embodiment of the present invention, the compression state of the model is constructed in the finite element software to simulate the force value when the model is compressed; the physical parameters of the model are changed to simulate the force value state when the model is compressed under different parameters to explore the influence of different parameters of the model on the compression state and obtain different compression force-displacement curves.

[0068] S400, determining a stiffness adjustment relationship of a bending crease model according to the relationship between the compression force and the displacement;

[0069] In the embodiment of the present invention, the compression force-displacement curve is analyzed and the principle of stiffness adjustment is obtained according to different stiffness characteristics.

[0070] S500, constructing a quasi-zero stiffness crease pattern according to the bending crease model and its corresponding stiffness adjustment relationship;

[0071] S600: constructing a corresponding fabric three-dimensional unit according to the quasi-zero stiffness crease pattern to obtain a target fabric vibration isolator.

[0072] In the embodiment of the present invention, a three-dimensional unit model with curved creases is established in Solidworks according to the crease pattern, and the same fabric three-dimensional unit is constructed using fabric samples.

[0073] In summary, the preparation method of the fabric vibration isolator provided by the present invention starts from the bending and folding forms of the fabric, and constructs a bending crease model by combining the two forms of fabric bending and folding, giving material properties to the fabric raw material, inputting boundary conditions into the established bending crease model, constructing it into a compression state, and revealing the principle that the stiffness of the crease model is adjustable; constructing a fabric three-dimensional unit based on the bending crease model, the fabric vibration isolator prepared by the preparation method of the fabric vibration isolator can make up for the shortcomings of the linear vibration isolator in that the vibration isolation ability is poor at low frequencies, and at the same time has good bearing capacity.

[0074] In the embodiment of the present invention, a bending crease model is constructed according to the vibration isolation characteristics of the target fabric vibration isolator, such as Figure 2 As shown, including:

[0075] S110, determining parameter information of the arc according to the vibration isolation characteristics of the target fabric vibration isolator;

[0076] It should be understood that according to the vibration isolation characteristics of the target fabric vibration isolator, the target requirements for the vibration isolation characteristics are determined, and according to the target requirements, the parameter information of the arc is determined, for example, the radian of the arc and other parameters are determined.

[0077] S120, creating two arcs located in two identical planes according to the arc parameter information;

[0078] The two deformation forms of fabric bending and folding are combined, and a bending crease model is constructed in Solidworks. The bending state of the fabric is simulated by constructing arcs.

[0079] S130, extending two identical arcs respectively to obtain two curved surfaces spliced ​​at a preset angle;

[0080] Specifically, two identical arcs are extended respectively to obtain two curved surfaces spliced ​​at a preset angle, including:

[0081] 1) stretching an arc located in a first plane in a direction perpendicular to the first plane to obtain a first curved surface;

[0082] 2) The arc located in the second plane is stretched to form the first curved surface to obtain a second curved surface, and the second curved surface is spliced ​​with the first curved surface at a preset angle.

[0083] S140, cutting the redundant parts outside the two spliced ​​curved surfaces to obtain a bending crease model.

[0084] Specifically, the arc in the first plane is stretched in a direction perpendicular to the first plane, and stretched a certain distance to obtain a first curved surface. An arc with the same curvature is made on the second plane, and the arc is stretched perpendicular to the second plane to form the first curved surface to obtain a second curved surface. The two curved surfaces form a crease, the part of the first curved surface that exceeds the crease is cut off, and then the two curved surfaces are stitched together to obtain a curved crease model.

[0085] In an embodiment of the present invention, the method for preparing the fabric vibration isolator further comprises, before the step of performing finite element analysis on the bending crease model:

[0086] Obtain the preset fabric material properties.

[0087] In the embodiment of the present invention, in view of the characteristics of denim being both stiff and flexible, the bending crease model is given denim material properties. The fabric sample is placed between the angles of the tensile testing machine, the two ends of the sample are kept fixed, and the equipment is started for testing to obtain the material properties of the fabric sample.

[0088] More specifically, obtaining the preset fabric material property includes:

[0089] The preset fabric material is subjected to tensile, compression, shear, bending, hardness and fatigue experimental tests to obtain the physical and mechanical performance parameters of the preset fabric.

[0090] In the embodiment of the present invention, a compression simulation is performed on a bending crease model with preset fabric material properties to obtain a compression force and displacement relationship of the bending crease model, such as Figure 3 As shown, including:

[0091] S310, constructing a compression state of the bending crease model according to a preset fabric material property assigned by the bending crease model to simulate a force value when the bending crease model is compressed;

[0092] S320, changing the physical parameter information of the bending crease model to simulate the force state of the bending crease model when it is compressed under different physical parameters, and obtaining the relationship between the compression force and displacement of the bending crease model.

[0093] Specifically, through finite element analysis, the influence of bending crease model parameters (chord height h, folding angle β) on the model stiffness is explored, and the influence of different parameters on the compression force-displacement curve is studied, and then the stiffness characteristics of the model after compression are evaluated to achieve quasi-zero stiffness.

[0094] Specifically, in an embodiment of the present invention, the bending crease model is assembled, two reference points are created on both sides of the bending crease model, the second reference point is fixed in all degrees of freedom, and the first reference point is displaced by a certain distance to compress the bending crease model. The grid density is set to divide the grid. In the grid unit type, it is set to S4R for analysis. In the simulation process, other parameters are controlled unchanged, and the chord height h is changed to obtain different compression force-displacement curves; then other variables are continued to be controlled unchanged, and the folding angle β is changed to obtain different compression force-displacement curves.

[0095] The stiffness of the finite element simulation adjustment model was experimentally verified by the fabric. Different fabric samples were taken for quasi-static compression experiments. Fabric samples with a length and width of 50mm×30mm were cut from the sample fabrics and constructed into a structure identical to the bending crease model. Nine different fabric samples were tested and the compression force-displacement curves were obtained.

[0096] In the embodiment of the present invention, the stiffness adjustment relationship of the bending crease model is determined according to the relationship between the compression force and the displacement, such as Figure 4 As shown, including:

[0097] S410, determining the stiffness characteristics of the bending crease model according to the relationship between the compression force and the displacement;

[0098] S420: Determine a stiffness adjustment relationship of the bending crease model according to the stiffness characteristics of the bending crease model.

[0099] It should be understood that the change in the stiffness characteristics of the bending crease model can be seen relatively clearly based on the compression force-displacement curve, that is, the stiffness characteristics of the bending crease model can be clearly determined based on the relationship between the compression force and the displacement, and the stiffness adjustment relationship of the bending crease model can be determined due to the change in the stiffness characteristics.

[0100] In the embodiment of the present invention, the corresponding three-dimensional fabric unit is constructed according to the quasi-zero stiffness crease pattern, such as Figure 5 As shown, including:

[0101] S610, selecting a fabric sample;

[0102] S620, marking the fabric sample according to the quasi-zero stiffness crease pattern, and marking creases and folding lines on the fabric sample;

[0103] S630, constructing a three-dimensional fabric unit by folding and sewing.

[0104] Specifically, based on the adjustable stiffness mechanism of the bending crease model, a quasi-zero stiffness three-dimensional unit and a positive stiffness three-dimensional unit of the fabric are designed respectively, and the crease curvatures of the two units are different. In addition, compression tests are carried out on the two fabric units to evaluate the stiffness characteristics of the fabric system, and the experimental results are compared and analyzed with the results of finite element simulation. Finally, a vibration test is carried out on the fabric unit.

[0105] In the embodiment of the present invention, denim is still selected as the material for designing the three-dimensional unit of the fabric. First, a crease pattern with quasi-zero stiffness is designed, and a three-dimensional unit structure model is constructed in Solidworks. The sample fabric is cut into the flat folding pattern shown, and the creases and folding lines are marked. The three-dimensional unit of the fabric is constructed by folding and sewing. Then, a crease pattern with positive stiffness is designed, and the three-dimensional unit structure model is constructed in Solidworks in the same way, and the sample fabric is used to construct the three-dimensional unit structure of the fabric.

[0106] In an embodiment of the present invention, in order to verify the effectiveness of the method for preparing the fabric vibration isolator, the method for preparing the fabric vibration isolator further includes:

[0107] Performing a compression test on the three-dimensional unit model with the bending crease to verify the quasi-zero stiffness characteristic of the three-dimensional unit model with the bending crease;

[0108] An isolation vibration experiment is performed on the fabric three-dimensional unit to verify the vibration isolation performance of the fabric three-dimensional unit.

[0109] Specifically, a compression experiment was carried out on the designed fabric unit structure. First, a finite element simulation analysis was performed to construct the compressed form of the fabric unit model. Secondly, a compression test was carried out on the fabric unit of the fabric structure. The compression force-displacement curves under two compression methods were obtained to evaluate the stiffness characteristics of the fabric unit.

[0110] In an embodiment of the present invention, in order to test the vibration isolation performance of the designed quasi-zero stiffness fabric three-dimensional unit, the designed fabric unit array is placed on the constructed experimental platform in turn. The upper and lower surfaces of the platform can detect the amplitudes of the upper and lower surfaces of the fabric unit. The experimental frequency is changed in turn to obtain the vibration isolation performance of the fabric unit array at low frequency.

[0111] Therefore, the preparation method of the fabric isolator provided by the present invention, the designed fabric isolator has nonlinear force under a specific load, and exhibits a quasi-zero stiffness phenomenon. Compared with linear isolators with linear stiffness, it can effectively isolate vibrations at low frequencies and has a certain load-bearing capacity. Moreover, the fabric is a flexible material and also makes a certain contribution to reducing damage to the isolated object.

[0112] The preparation process and experimental verification process of the preparation method of the fabric vibration isolator provided in the embodiment of the present invention are described in detail below to illustrate the feasibility of the preparation method of the fabric vibration isolator and the vibration isolation characteristics of the prepared fabric vibration isolator.

[0113] (1) The preparation process of the bending crease model is as follows Figure 6 As shown, the changes of a single form of fabric are combined to construct a bending crease model. First, simulate the bending state of the fabric by constructing an arc S1, where h is the chord height of the arc and d is the chord length of the arc. The arc is stretched in a direction perpendicular to the plane 1 where the arc is located. The first bending surface is obtained by stretching a certain distance. As a developable surface, it can be unfolded into a plane without in-plane deformation such as stretching and shearing. Make an arc S2 with the same curvature as S1 on plane 2, and stretch S2 perpendicular to plane 2 to the first surface to obtain a second surface. The two surfaces form a crease, and the angle formed by the two surfaces is β. The excess part of the first surface is cut off and split and removed to obtain a bending crease model.

[0114] (2) Obtain material properties in the finite element model, and obtain the basic physical and mechanical performance parameters of the fabric through experimental tests such as stretching, compression, shearing, bending, hardness, and fatigue of the fabric material. The fabric's elastic modulus, Poisson's ratio, and density are assigned to the bending crease model, making the numerical values ​​obtained by the model during the finite element analysis more accurate.

[0115] (3) The finite element simulation conditions are set as follows Figure 7As shown, two reference points are created, Rp-2 is fixed in all degrees of freedom, and Rp-1 is applied with a displacement of 17 mm along the negative direction of the x-axis to compress the bending crease model. The mesh density of the model is set to 1 for meshing, and finally divided into 1650 units. In the mesh unit type, it is set to S4R for analysis.

[0116] The results are obtained in the visualization module. The compression force-displacement curve obtained by finite element simulation is analyzed. It is assumed that the two curved panels are smoothly connected. The force received during the whole process is composed of the force at the crease and the force at the bend. Keeping other parameters unchanged, the angle β is set to 130°, and the chord height h of the model is set to 2, 3.5, 4.5 and 5.5 mm respectively. The influence of the above different chord height parameters on the model stiffness is compared, and the force-displacement curve is drawn, as shown in the figure. Figure 8a shown.

[0117] Depend on Figure 8a It can be seen that different chord heights h show different stiffness curves. When the chord height h = 2mm, the initial load value increases rapidly to 30cN, and the curve shows a phenomenon of positive stiffness to negative stiffness; then as the h value increases to 3.5mm, the initial load decreases to 21cN, and the curve shows a zero stiffness phenomenon between 5mm and 12.5mm; after h increases to 4.5mm, the curve shows a slow growth trend, and the overall performance is positive stiffness. Since the arc length is fixed and will not change with the change of the chord height, when the chord height h increases, in order to ensure that the arc length remains unchanged, the chord length d will decrease accordingly, which is reflected in the model as the bending degree of the crease further increases, which is manifested as an increase in the curvature of the crease, which makes the folding process of the model easier to achieve, reduces the energy ratio at the crease, and increases the energy ratio of the panel bending, forming a transition from negative stiffness to positive stiffness.

[0118] The chord length d is set to 29 mm, the chord height h is set to 3.5 mm, and the influence of different folding angles β on the stiffness adjustment of the model is explored. The compression force-displacement curve is shown in Figure 8b As shown in the figure, in the initial stage of displacement between 0 and 2 mm, the curves of all angles show positive stiffness; when the angle β is 90° and 110°, in the range of 2.5 mm to 10 mm, the curve shows a slight negative stiffness; when the angle β is 130°, the curve shows a quasi-zero stiffness in the range of 2.5 mm to 12.5 mm; when β increases to 150°, the curve shows a positive stiffness as a whole. It can be seen that with the increase of the angle β value, the curve shows a transition from negative stiffness to positive stiffness. This is because the increase in the β value increases the curvature of the crease and reduces the ratio of energy occupied by the crease area.

[0119] (4) The simulation of adjusting the stiffness of the model based on finite element analysis was verified by fabric experiments. Different fabric samples were taken for compression tests. Before the experiment, the test fabric samples were left to stand for 24 hours at a temperature of (20±3)°C and a relative humidity of (65±3)%. Fabric samples with a length and width of 50 mm x 30 mm were cut from the fabric samples and constructed into a structure identical to the bending crease model. The fabric samples were subjected to compression tests in the same compression form as the finite element simulation. Fabric samples of 9 different fabric types and raw materials were tested. The fabric samples had a fixed chord length of 29 mm and a chord height of 3.5 mm. Compression tests were performed at angles of 110°, 130°, and 150°, respectively. The compression force-displacement curve test results are shown in Figure 2. Fig. 9 As shown in the figure, the force-displacement curves of the fabric model at angles of 110°, 130° and 150° show negative stiffness, quasi-zero stiffness and positive stiffness respectively, which are highly similar to the compression force-displacement curve trends obtained by finite element simulation, verifying the correctness of finite element simulation. As can be seen from the figure, the greater the thickness of the same type of fabric, the greater the force value under the same displacement; the curves of plain fabrics 7 and 8 are relatively flat, and the curves of twill fabrics are relatively steep. This is because the plain weave has many interlacing points, the free movement space of the yarn is small when compressed, and the resulting pressure resistance is small; the smaller the gram weight, the closer the curve trends of the fabric samples at the three angles.

[0120] (5) For a single fabric bending crease unit, it is difficult to implement end-point loading, and the shape change during deformation is difficult to predict and control. Therefore, the single unit is assembled into a cubic structure by splicing and sewing, which can not only achieve stable loading but also control its shape change. The crease design pattern based on the quasi-zero stiffness curve is as follows: Fig.10a As shown, a three-dimensional unit structure is constructed in Solidworks, and the sample fabric is cut into the flat folding pattern shown. The creases and folding lines are marked, and the fabric three-dimensional unit is constructed by folding and sewing. The fabric unit designed with the crease design pattern is named #1. The crease design pattern based on the positive stiffness curve is shown in Fig.10b As shown, a three-dimensional unit structure is constructed in Solidworks in the same way, and a sample cloth is used to construct a fabric three-dimensional unit structure. The fabric unit designed with this crease design pattern is named #2. In this structure, it can be regarded as a combination of three curved crease units and two panels. This designed structure can maintain rigid and regular foldability and reproduce the deformation mode of each unit. A static experiment is carried out on the designed structure, which is divided into two parts: first, a finite element simulation analysis is carried out, and the model is assembled with two plates to form a clamping state between the two plates, with the moving plate on the top and the fixed plate on the bottom. The analysis step uses display dynamics for analysis. The load, constraint and mesh settings are as follows: Fig.11As shown, the top moving plate is displaced 14 mm along the negative direction of the x-axis. Compression tests are then performed on #1 and #2, and the fabric compression conditions are set consistent with the finite element simulation conditions.

[0121] Comparison of the compression force-displacement curves of #1 and #2 from finite element simulation and experimental compression is shown in Fig.12 As shown in the experimental curves, #1 and #2 show quasi-zero stiffness characteristics and positive stiffness characteristics respectively. The finite element simulation curve is close to the experimental curve trend, but it is difficult to ensure complete consistency between the sample stitching, resulting in incomplete overlap of the curves. Fig.12 The correlation analysis between the simulation and experimental data of the same sample was performed. The correlation coefficient between the experimental and simulation results of sample #1 was 0.833, and the correlation coefficient between the experimental and simulation results of sample #2 was 0.911. Both were significantly correlated at the 0.01 level, indicating that there was a high correlation between the experimental and simulation data. Fig.12 It can be seen that #1 exhibits quasi-zero stiffness under a load of 35g, while #2 exhibits positive stiffness under this load.

[0122] (6) To test the vibration isolation performance of the designed quasi-zero stiffness fabric stereo unit and positive stiffness fabric stereo unit, three #1 cubic units were used as an array and three #2 cubic units were used as an array to construct two arrays for vibration isolation experiments. Double-sided tape was adhered to the upper and lower surfaces of the three cubic units and adhered to the upper and lower acrylic plates. Two light-weight sensors were installed on the upper and lower acrylic plates to detect the input amplitude and the amplitude after vibration transmission. Weights were applied to the upper acrylic plate. The total weight of the acrylic plate, weights and sensors was 105g, so that the two fabric stereo unit arrays reached quasi-zero stiffness and positive stiffness, named A and B respectively. Excitation vibration was applied to the lower acrylic plate. The initial input excitation frequency was set to 5Hz. After obtaining the input and output amplitudes, the frequency was changed to 6Hz for experiment and data collection, and the data was recorded to 25Hz.

[0123] The amplitude-time responses of the two fabric unit arrays under a load of 105g are shown in Figure 2. Fig.13a and Fig.13b As shown in the figure, the hollow dashed line represents the input amplitude and the solid dashed line represents the output amplitude. The load response of the quasi-zero stiffness fabric unit array at the initial frequency of 5 Hz and the vibration isolation frequency of 18 Hz is shown in the figure. Fig.13a As shown in the figure, the load response of the positive stiffness fabric unit array at the initial frequency of 5 Hz and the transmitted vibration frequency of 22 Hz is as follows: Fig.13b It can be seen that the input and output amplitudes of the two fabric arrays at 5Hz are similar, and the amplitude ranges of the two amplitudes are highly close; the output amplitude of the quasi-zero stiffness fabric array is smaller than the input amplitude at the isolation frequency, and the output amplitude of the positive stiffness fabric array is larger than the input amplitude at the transmission frequency.

[0124] According to the amplitude time domain data obtained at each frequency, the RMS value of the input and output amplitudes is calculated and substituted into the transferability calculation formula The amplitude transmissibility of the quasi-zero stiffness fabric array A and the positive stiffness fabric array B from 5 to 25 Hz is obtained, as Fig.14 shown.

[0125] from Fig.14 It can be seen that the transmissibility of the quasi-zero stiffness fabric array A in the frequency range shown is less than zero, and the transmissibility increases first and then decreases, showing good low-frequency vibration isolation performance; the transmissibility of the positive stiffness fabric array B in the frequency range shown is greater than zero. Under the conditions of frequency 18Hz and 105g load, the amplitude transmissibility of fabric array A is -14.5dB, at which the vibration isolation phenomenon is optimal; the amplitude transmissibility of fabric array B at 22Hz is 17dB, and the vibration transmission phenomenon reaches its maximum.

[0126] From the dynamic behavior, we can see that fabric array A can effectively isolate vibration at low frequencies. Fabric is a flexible material, and the distribution of yarns has a certain energy dissipation mechanism, which will absorb the energy during vibration transmission. Therefore, when fabric array A is in quasi-zero stiffness, there is no vibration conduction phenomenon in fabric array A at low frequencies; while fabric array B is in positive stiffness under a load of 105g, and exhibits a phenomenon of amplified vibration within the frequency range shown, and has poor vibration isolation performance at low frequencies. Experiments have shown that the designed quasi-zero stiffness fabric unit isolator has superior vibration isolation performance than the positive stiffness fabric unit isolator.

[0127] As another embodiment of the present invention, a fabric vibration isolator is provided, which includes: a fabric vibration isolator prepared according to the method for preparing the fabric vibration isolator described above.

[0128] The fabric vibration isolator provided by the present invention is prepared by the preparation method of the fabric vibration isolator described above, and specifically comprises the following process steps: 1) Combining the two deformation forms of fabric bending and folding, first constructing two curved surfaces in Solidworks, splicing the two curved surfaces at a certain angle, cutting the excess parts, and stitching the curved surfaces to obtain a bending crease model. 2) Collecting the material properties of the denim fabric and assigning them to the bending crease model. 3) Constructing the compression state of the model in the finite element software, simulating the compression experiment, changing different parameters of the model and repeating the experimental simulation multiple times. 4) Taking a variety of fabric samples of different raw materials and types, cutting them into the same specification parameters as the bending crease model, and conducting a fabric compression experiment, changing the angles of the two curved surfaces of the fabric and repeating the experiment; the principle of adjustable stiffness is jointly explained by finite element simulation and experimental compression. 5) Based on the adjustable stiffness mechanism of the bending crease model, the fabric quasi-zero stiffness three-dimensional unit and the fabric positive stiffness three-dimensional unit are designed respectively, and the crease curvatures of the two units are different. In addition, compression tests were conducted on the two fabric units to evaluate the stiffness characteristics of the fabric system, and the experimental results were compared and analyzed with the results of finite element simulation. Finally, the fabric units were tested by vibration experiments. 6) The vibration isolation performance of the designed quasi-zero stiffness fabric three-dimensional unit and the positive stiffness fabric three-dimensional unit was tested. The two designed fabric unit arrays were placed on the constructed experimental platform in turn. The upper and lower surfaces of the platform can detect the amplitude of the upper and lower surfaces of the fabric unit. The experimental frequency was changed in turn to obtain the vibration isolation performance of the two fabric unit arrays at low frequencies and evaluate them. Starting from the common bending and folding forms of fabrics, the present invention designs a bending crease model that combines bending and folding forms, and reveals its adjustable stiffness mechanism through finite element and experimental methods. Based on this principle, a fabric three-dimensional unit with a specific bending crease is designed. The fabric unit with quasi-zero stiffness exhibits excellent vibration isolation capability and good load-bearing capacity at low frequencies. The quasi-zero stiffness fabric isolator combines the unique advantages of the quasi-zero stiffness principle and fabric materials, has excellent vibration isolation performance, light weight, cost-effectiveness and customizability, and provides an effective solution for modern engineering fields that require high-performance vibration isolation.

[0129] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a fabric vibration isolator, characterized in that: include: A bending crease model is constructed according to the vibration isolation characteristics of the target fabric isolator; Performing finite element analysis on the bending crease model, and assigning preset fabric material properties to the bending crease model; A compression simulation is performed on a bending crease model with preset fabric material properties to obtain the relationship between the compression force and displacement of the bending crease model; Determining the stiffness adjustment relationship of the bending crease model according to the relationship between the compression force and the displacement; Constructing a quasi-zero stiffness crease pattern according to the bending crease model and its corresponding stiffness adjustment relationship; The corresponding three-dimensional fabric unit is constructed according to the quasi-zero stiffness crease pattern to obtain a target fabric vibration isolator.

2. The method for preparing a fabric vibration isolator according to claim 1, characterized in that: The bending crease model is constructed according to the vibration isolation characteristics of the target fabric isolator, including: Determining parameter information of the arc according to the vibration isolation characteristics of the target fabric vibration isolator; Create two arcs located in two identical planes according to the arc parameter information; Extend two identical arcs respectively to obtain two surfaces spliced ​​at a preset angle; The excess parts outside the two spliced ​​surfaces are cut off to obtain the bending crease model.

3. The method for preparing a fabric vibration isolator according to claim 2, characterized in that: Extend two identical arcs to obtain two surfaces connected at a preset angle, including: Stretching the arc located in the first plane in a direction perpendicular to the first plane to obtain a first curved surface; The arc located in the second plane is stretched to be formed into the first curved surface to obtain a second curved surface, and the second curved surface is spliced ​​with the first curved surface at a preset angle.

4. The method for preparing a fabric vibration isolator according to any one of claims 1 to 3, characterized in that: A compression simulation is performed on a bending crease model with preset fabric material properties to obtain the relationship between the compression force and displacement of the bending crease model, including: The compression state of the bending crease model is constructed according to the preset fabric material properties assigned by the bending crease model to simulate the force value when the bending crease model is compressed; The physical parameter information of the bending crease model is changed to simulate the force state of the bending crease model when it is compressed under different physical parameters, and the relationship between the compression force and displacement of the bending crease model is obtained.

5. The method for preparing a fabric vibration isolator according to any one of claims 1 to 3, characterized in that: Determining the stiffness adjustment relationship of the bending crease model according to the relationship between the compression force and the displacement includes: Determining the stiffness characteristics of the bending crease model according to the relationship between the compression force and the displacement; The stiffness adjustment relationship of the bending crease model is determined according to the stiffness characteristics of the bending crease model.

6. The method for preparing a fabric vibration isolator according to any one of claims 1 to 3, characterized in that: The corresponding three-dimensional fabric unit is constructed according to the quasi-zero stiffness crease pattern, comprising: Select fabric swatches; Marking the fabric sample according to the quasi-zero stiffness crease pattern, and marking creases and folding lines on the fabric sample; The three-dimensional fabric unit is constructed by folding and sewing.

7. The method for preparing a fabric vibration isolator according to any one of claims 1 to 3, characterized in that: The preparation method of the fabric vibration isolator also includes: Performing a compression test on the three-dimensional unit model with the bending crease to verify the quasi-zero stiffness characteristic of the three-dimensional unit model with the bending crease; An isolation vibration experiment is performed on the fabric three-dimensional unit to verify the vibration isolation performance of the fabric three-dimensional unit.

8. The method for preparing a fabric vibration isolator according to any one of claims 1 to 3, characterized in that: The method for preparing the fabric vibration isolator further comprises the following steps before the step of performing finite element analysis on the bending crease model: Obtain the preset fabric material properties.

9. The method for preparing a fabric vibration isolator according to claim 8, characterized in that: Obtaining the preset fabric material properties includes: The preset fabric material is subjected to tensile, compression, shear, bending, hardness and fatigue experimental tests to obtain the physical and mechanical performance parameters of the preset fabric.

10. A fabric vibration isolator, characterized in that: include: A fabric vibration isolator prepared according to the method for preparing a fabric vibration isolator according to any one of claims 1 to 9.

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