Method for establishing 360-degree occlusion node equivalent spring model considering coupling effect

Abstract

The invention discloses a method for establishing a 360-degree occlusion node equivalent spring model considering a coupling effect, and the method comprises the following steps: a, analyzing the response characteristics of 360-degree occlusion nodes which are actually connected together under the action of a wind load; b, according to the response characteristics, decoupling 360-degree occlusion nodes into an equivalent spring combination structure, and establishing an equivalent spring model by considering a coupling effect; c, establishing a constitutive relation of an equivalent spring combination structure according to a coupling effect; d, acquiring load-displacement data of the 360-degree occlusion nodes which are actually connected together through the testing device; e, according to the load-displacement data, analyzing a constitutive relation of an equivalent spring combination structure in the equivalent spring model, and obtaining a spring attribute of the equivalent spring combination structure; and f, inputting the spring attributes of the equivalent spring into an equivalent spring model, and comparing the response results of the equivalent spring model and the 360-degree occlusion nodes which are actually connected together under the action of the wind load to verify the effectiveness of the equivalent spring model.

Description

Technical Field

[0001] The invention relates to the technical field of building structure testing, and in particular to a method for establishing a 360-degree bite node equivalent spring model considering coupling effects. Background Art

[0002] In the construction industry, metal panels are widely used in roofs, walls and other parts due to their good aesthetics and functionality. The panels are connected by bite, which generally have a variety of bite forms, including upright lock edge bite structure, 360° bite structure, etc. However, with the increase of wind load, the wind bearing capacity of metal panels becomes an important issue.

[0003] For 360° interlocking structures, the existing wind bearing capacity test methods have problems such as low test accuracy and complex operation, and cannot accurately evaluate the wind resistance of metal panels. Therefore, in order to evaluate the wind bearing capacity of metal panels, a three-way decoupled spring model was proposed to simulate the mechanical behavior of the node, that is, the 360° interlocking structure is decoupled into three equivalent springs, including horizontal springs, vertical springs and rotational springs, and the mechanical properties of the interlocking node in three directions are characterized by equivalent springs in three directions. However, the existing three-way equivalent springs are relatively independent, and the error between the simulation results and the actual test results is large, and the accuracy is not high.

[0004] Therefore, some scholars have found that the reason for the above problem is that there is a coupling effect between the three-way spring stiffness of the 360° interlocking metal panel node, such as the coupling effect between the horizontal direction and the rotation direction will affect its unidirectional mechanical properties, that is, at different rotation angles, the horizontal force required for the node to produce the same horizontal displacement is different. Therefore, a 360° interlocking node spring model that considers the spring coupling effect is needed to solve this problem, but there is currently no relevant equivalent spring model and its establishment method. Summary of the invention

[0005] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a method for establishing a 360° bite node equivalent spring model taking into account the coupling effect, thereby solving the problem in the prior art that the coupling effect between equivalent springs is not taken into account, resulting in poor bite node test results.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] A method for establishing a 360° snap node equivalent spring model considering coupling effect comprises the following steps:

[0008] a. Analyze the response characteristics of the 360° interlocking nodes actually connected together under wind loads;

[0009] b. According to the response characteristics, the 360° bite node is decoupled into an equivalent spring combination structure, and an equivalent spring model is established considering the coupling effect;

[0010] c. Establish the constitutive relationship of the equivalent spring combination structure based on the coupling effect;

[0011] d. Obtain the load-displacement data of the 360° interlocking nodes actually connected together through the test device;

[0012] e. Analyzing the constitutive relationship of the equivalent spring combination structure in the equivalent spring model according to the load-displacement data to obtain the spring properties of the equivalent spring combination structure;

[0013] f. Input the spring properties of the equivalent spring into the equivalent spring model, and compare the response results of the equivalent spring model and the actual 360° interlocking nodes connected together under wind load to verify the validity of the equivalent spring model.

[0014] As an optimization, the 360° bite node includes a horizontally arranged panel, and two ends of the panel are bent and extended upward to form a first bite portion and a second bite portion;

[0015] The first engaging portion includes a first vertical plate formed by bending and extending the panel upward, a first flat plate formed by bending and extending to a side away from the panel, a second vertical plate formed by bending and extending downward, a second flat plate formed by bending and extending to a side close to the panel, and a third vertical plate formed by bending and extending upward, and there are gaps between the first vertical plates, between the second vertical plates and the third vertical plates, and between the upper end of the third vertical plate and the first flat plate;

[0016] The second engaging portion includes a fourth vertical plate formed by bending and extending the panel upward, a third flat plate formed by bending and extending toward a side close to the panel, and a fifth vertical plate formed by bending and extending downward;

[0017] When the first engaging portion of the panel engages with the second engaging portion of the adjacent panel, the fifth vertical plate engages in the gap between the second vertical plate and the third vertical plate, the third flat plate engages in the gap between the upper end of the third vertical plate and the first flat plate, and the fourth vertical plate engages in the gap between the first vertical plate and the third vertical plate.

[0018] As an optimization, it also includes a support, which includes a horizontally arranged substrate, and a sixth vertical plate formed by bending and extending one end of the substrate upward, a fourth flat plate formed by bending and extending to a side away from the substrate, a seventh vertical plate formed by bending and extending downward, a fifth flat plate formed by bending and extending to a side close to the substrate, and an eighth vertical plate formed by bending and extending upward. When engaged, the eighth vertical plate is engaged between the third vertical plate and the fifth vertical plate, the seventh vertical plate is engaged between the second vertical plate and the fifth vertical plate, the sixth vertical plate is engaged between the first vertical plate and the fourth vertical plate, and the fourth flat plate is engaged between the first flat plate and the third flat plate.

[0019] As an optimization, the equivalent spring combination structure includes a multi-axis spring with two nodes and multiple degrees of freedom at the nodes, and the nodes can generate lateral displacement, vertical displacement or rotation angle under the action of force.

[0020] As an optimization, in step c,

[0021] According to the tensile constitutive relation of common metal materials, the yield function and strengthening law of the multi-axis spring are proposed and expressed by the following formula:

[0022]

[0023] Where f is the spring force, b1, γ1, b2, γ2 are material parameters, a0 is the initial yield surface, a1 is the maximum subsequent yield surface, and m is the yield surface change rate. is the equivalent spring relative plastic displacement, where Calculated by the following formula,

[0024]

[0025] In the formula, is a tensor, representing the relative plastic displacement in each degree of freedom;

[0026] From equations (1) and (2), it can be obtained that the constitutive relationship of the multi-axis spring when it is one degree of freedom is as follows:

[0027]

[0028] Combined with the spring displacement composition, we have:

[0029]

[0030] In the formula, u i is the relative displacement of the spring, K i is the spring stiffness in the i degree of freedom;

[0031] Substituting equations (3) and (4) into equation (5), we can obtain the displacement-force relationship of the multi-axis spring under each degree of freedom, that is,

[0032]

[0033]

[0034] Where b i and γ i Both represent the spring stiffness influence coefficients of the multi-axial spring with i degrees of freedom on the node performance, u1 and u i+1 is the relative displacement between two nodes of the multi-axial spring with corresponding degrees of freedom, f1 and f i+1 is the spring force of the multi-axis spring corresponding to the degree of freedom.

[0035] As an optimization, the testing device includes a horizontal stiffness testing device, a vertical stiffness testing device and a rotational stiffness testing device, which are respectively used to test the horizontal stiffness, vertical stiffness and rotational stiffness of the multi-axis spring.

[0036] As an optimization, the horizontal stiffness test device includes two first clamping assemblies arranged opposite to each other, respectively used to clamp the two side panels of the 360° bite node that are bitten together;

[0037] Wherein, the first clamping assembly comprises a bottom plate and a back plate which are arranged relatively parallel, the back plate is connected to the bottom plate by bolts, and the panel is clamped between the bottom plate and the back plate; the two ends of the two bottom plates which are separated from each other are respectively formed with clamping ends, which are respectively used to connect with the loading device and fix the bottom plate;

[0038] The loading device can drive the two first clamping components to move away from each other, so that the 360° bite node produces horizontal displacement, and the horizontal stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0039] As an optimization, the vertical stiffness test device includes a bracket with a door-shaped structure, and an extension plate is respectively provided at the lower end of the two supporting feet of the bracket, and the two extension plates extend in a direction close to each other, and there is a gap between the ends of the two extension plates that are close to each other; a pressing plate is provided on the lower side of the two extension plates, and the pressing plate is connected to the extension plate by bolts, and two panels of the 360° bite nodes that bite together are clamped between the pressing plate and the extension plate;

[0040] A base is also fixedly provided below the bracket for fixing the support, wherein the base plate of the support is fixed to the base by bolts; a clamping end is provided at the upper end of the bracket for connecting with the loading device;

[0041] The loading device can drive the bracket away from the base, causing vertical displacement between the support of the 360° interlocking node and the two interlocking panels. The vertical stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0042] As an optimization, the rotational stiffness testing device includes two rotating components arranged opposite to each other in an upper and lower direction, and the rotating components include a rotating shaft, rotating plates are vertically provided at both ends of the rotating shaft, and a clamping plate is installed between the same sides of the two rotating plates for clamping the panels of the 360° bite node that are bitten together; a counterweight is installed between the two rotating plates on the side away from the clamping plate; a connecting rod is also rotatably installed on the rotating shaft, and the connecting rods of the two rotating components are respectively used to connect and fix with the loading device, and the loading device can make the two rotating shafts move away from each other through the connecting rod, so that a rotation angle is generated between the two panels of the 360° bite node that are bitten together, and the rotational stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0043] As an optimization, in step f, a verification device is used to test the three-way coupled deformation of the 360° interlocking nodes that are actually interlocked together under wind loads to verify the validity of the equivalent spring model;

[0044] Among them, the verification device includes a fixed seat and a simulation frame above the fixed seat. The simulation frame is a door-shaped structure, and the lower ends of its two legs are bent and extended in opposite directions to form a connecting plate. The two panels of the 360° bite node that are interlocked together are connected to the connecting plate by bolts respectively. The base plate of the support of the 360° bite node is fixed on the fixed seat. The upper end of the simulation frame is connected to the loading device. The loading device can drive the simulation frame away from the fixed seat, so that the 360° bite node produces three-way coupled deformation. The validity of the equivalent spring model is verified by the load-displacement data of the loading device.

[0045] Compared with the prior art, this application has the following beneficial effects:

[0046] The present invention establishes an equivalent spring model by considering the coupling effect between the three-way stiffness of the 360° interlocking node of the metal panel, and establishes the constitutive relationship of the equivalent spring. The constitutive relationship of the equivalent spring is analyzed by the load-displacement data of the test device, and the parameters characterizing the spring properties in the equivalent spring are obtained. The validity of the equivalent spring model is verified by comparing with the force conditions of the actual interlocking nodes. The present invention takes into account the coupling effect of the interlocking node, so that the test results of the interlocking node are more accurate and have higher precision, and can better evaluate the wind resistance of the metal panel, providing theoretical guidance for engineering design. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 It is a schematic diagram of the principle of the coupling effect between the various stiffnesses in the present invention;

[0048] Figure 2 A model diagram of a multi-axis spring in the present invention;

[0049] Figure 3 It is a structural schematic diagram of the horizontal stiffness test device;

[0050] Figure 4 It is a structural schematic diagram of the vertical stiffness testing device;

[0051] Figure 5 It is a structural schematic diagram of the rotation stiffness testing device;

[0052] Figure 6 It is a schematic diagram of the structure of the verification device;

[0053] Figure 7 It is a comparison curve between the simulation result and the test result of the equivalent spring model of the present invention;

[0054] In the figure, 1 is the bottom plate, 2 is the back plate, 3 is the bracket, 4 is the extension plate, 5 is the pressure plate, 6 is the base, 7 is the rotating shaft, 8 is the rotating plate, 9 is the splint, 10 is the counterweight, 11 is the connecting rod, 12 is the fixed seat, 13 is the simulation frame, 14 is the connecting plate, and 15 is the 360° bite node. DETAILED DESCRIPTION

[0055] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0056] For specific implementation: see Figure 1-7 ,

[0057] A method for establishing a 360° snap node equivalent spring model considering coupling effect comprises the following steps:

[0058] a. Analyze the response characteristics of the 360° interlocking nodes actually connected together under wind loads.

[0059] Specifically, the 360° bite node 15 includes a horizontally arranged panel, and two ends of the panel are bent and extended upward to form a first bite portion and a second bite portion;

[0060] The first engaging portion includes a first vertical plate formed by bending and extending the panel upward, a first flat plate formed by bending and extending to a side away from the panel, a second vertical plate formed by bending and extending downward, a second flat plate formed by bending and extending to a side close to the panel, and a third vertical plate formed by bending and extending upward, and there are gaps between the first vertical plates, between the second vertical plates and the third vertical plates, and between the upper end of the third vertical plate and the first flat plate;

[0061] The second engaging portion includes a fourth vertical plate formed by bending and extending the panel upward, a third flat plate formed by bending and extending toward a side close to the panel, and a fifth vertical plate formed by bending and extending downward;

[0062] When the first engaging portion of the panel engages with the second engaging portion of the adjacent panel, the fifth vertical plate engages in the gap between the second vertical plate and the third vertical plate, the third flat plate engages in the gap between the upper end of the third vertical plate and the first flat plate, and the fourth vertical plate engages in the gap between the first vertical plate and the third vertical plate.

[0063] It also includes a support, which includes a horizontally arranged base plate, and a sixth vertical plate formed by bending and extending upward from one end of the base plate, a fourth flat plate formed by bending and extending to a side away from the base plate, a seventh vertical plate formed by bending and extending downward, a fifth flat plate formed by bending and extending to a side close to the base plate, and an eighth vertical plate formed by bending and extending upward. When engaged, the eighth vertical plate is engaged between the third vertical plate and the fifth vertical plate, the seventh vertical plate is engaged between the second vertical plate and the fifth vertical plate, the sixth vertical plate is engaged between the first vertical plate and the fourth vertical plate, and the fourth flat plate is engaged between the first flat plate and the third flat plate.

[0064] b. According to the response characteristics, the 360° bite node 15 is decoupled into an equivalent spring combination structure, and an equivalent spring model is established considering the coupling effect.

[0065] Specifically, there is a coupling effect between the three-way spring stiffness of the 360° interlocking metal panel nodes, such as Figure 1 The figure shows the influence of the coupling effect between the horizontal direction and the rotation direction, that is, when the rotation angle is different, the horizontal force required for the node to produce the same horizontal displacement is different.

[0066] Therefore, in the present invention, the equivalent spring combination structure includes a multi-axis spring with two nodes (I and J nodes) and multiple degrees of freedom (such as 1, 2, and 3 degrees of freedom) at the nodes, and the nodes can generate lateral displacement, vertical displacement or rotation angle under the action of force. Figure 2 As shown, compared with the existing independent triaxial spring, the coupling effect between the three-way stiffness at the node can be characterized by the load-displacement constitutive relationship at the node, the model is simpler and the calculation is more convenient.

[0067] c. Establish the constitutive relationship of the equivalent spring combination structure based on the coupling effect.

[0068] Specifically, referring to the tensile constitutive relation of common metal materials, the yield function and strengthening law of the multi-axis spring are proposed and expressed by the following formula:

[0069]

[0070] Where f is the spring force, b1, γ1, b2, γ2 are material parameters, a0 is the initial yield surface, a1 is the maximum subsequent yield surface, and m is the yield surface change rate. is the equivalent spring relative plastic displacement, where Calculated by the following formula,

[0071]

[0072] In the formula, is a tensor, representing the relative plastic displacement in each degree of freedom;

[0073] From equations (1) and (2), it can be obtained that the constitutive relationship of the multi-axis spring when it is one degree of freedom is as follows:

[0074]

[0075] Combined with the spring displacement composition, we have:

[0076]

[0077] In the formula, u i is the relative displacement of the spring, K i is the spring stiffness in the i degree of freedom;

[0078] Substituting equations (3) and (4) into equation (5), we can obtain the displacement-force relationship of the multi-axis spring under each degree of freedom, that is,

[0079]

[0080]

[0081] Where b i and γ i Both represent the spring stiffness influence coefficients of the multi-axial spring with i degrees of freedom on the node performance, u1 and u i+1 is the relative displacement between two nodes of the multi-axial spring with corresponding degrees of freedom, f1 and f i+1 is the spring force of the multi-axis spring corresponding to the degree of freedom.

[0082] At the same time, based on formula (1), the yield function of the biaxial spring (two degrees of freedom) can be simplified as follows:

[0083]

[0084] Similar to equations (1) and (2), the relationship between the node displacement u and the spring force f under each degree of freedom can be derived:

[0085]

[0086]

[0087] The common parameters a0, a1, and m in the two equations indicate that there is a coupling relationship between the two, while the unique parameter b i , γ iRepresents the effect of the i-degree-of-freedom spring on the performance of the node.

[0088] d. Obtain the load-displacement data of the 360° interlocking nodes 15 that are actually connected together through the testing device.

[0089] Specifically, the testing device includes a horizontal stiffness testing device, a vertical stiffness testing device and a rotational stiffness testing device, which are respectively used to test the horizontal stiffness, vertical stiffness and rotational stiffness of the multi-axis spring.

[0090] The horizontal stiffness testing device comprises two first clamping assemblies arranged opposite to each other, respectively used to clamp two side panels of a 360° bite node 15 that are bitten together;

[0091] The first clamping assembly comprises a bottom plate 1 and a back plate 2 which are arranged in parallel with each other, the back plate 2 is connected to the bottom plate 1 by bolts, and the panel is clamped between the bottom plate 1 and the back plate 2; the two ends of the two bottom plates 1 which are separated from each other are respectively formed with clamping ends, which are respectively used to connect with the loading device and fix the bottom plate 1;

[0092] The loading device can drive the two first clamping components to move away from each other, so that the 360° bite node 15 produces a horizontal displacement, and the horizontal stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0093] The vertical stiffness test device comprises a support 3 of a door-shaped structure, wherein an extension plate 4 is respectively provided at the lower ends of two support feet of the support 3, and the two extension plates 4 extend in a direction close to each other, and a gap is provided between the ends of the two extension plates 4 close to each other; a pressing plate 5 is provided at the lower side of the two extension plates 4, and the pressing plate 5 is connected to the extension plate 4 by bolts, and two panels of 360° bite nodes 15 that bite together are clamped between the pressing plate 5 and the extension plate 4;

[0094] A base 6 is also fixedly provided below the bracket 3 for fixing the bracket, wherein the base plate of the bracket is fixed to the base 6 by bolts; a clamping end is provided at the upper end of the bracket 3 for connecting with the loading device;

[0095] The loading device can drive the bracket 3 away from the base 6, so that a vertical displacement occurs between the support of the 360° interlocking node 15 and the two interlocking panels, and the vertical stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0096] The rotational stiffness testing device includes two rotating components arranged opposite to each other in an upper and lower direction, and the rotating components include a rotating shaft 7, and rotating plates 8 are respectively vertically provided at both ends of the rotating shaft 7, and a clamping plate 9 is installed between the same sides of the two rotating plates 8 for clamping the panels of the 360° bite node 15 that are bitten together; a counterweight 10 is installed between the two rotating plates 8 on the side away from the clamping plate 9; a connecting rod 11 is also rotatably installed on the rotating shaft 7, and the connecting rods 11 of the two rotating components are respectively used to connect and fix with the loading device, and the loading device can make the two rotating shafts 7 move away from each other through the connecting rod 11, so that a rotation angle is generated between the two panels of the 360° bite node 15 that are bitten together, and the rotational stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

[0097] e. Analyzing the constitutive relationship of the equivalent spring combination structure in the equivalent spring model according to the load-displacement data to obtain the spring properties of the equivalent spring combination structure;

[0098] Specifically, equations (6) and (7) can be used to fit the spring parameters of the triaxial spring, and equations (9) and (10) can be used to fit the spring parameters of the biaxial spring. The following spring model parameters are obtained by sorting them out. The least squares method can be used to fit the test data and the above equations to obtain the parameters in the table.

[0099]

[0100] f. Input the spring properties of the equivalent spring into the equivalent spring model, and compare the response results of the equivalent spring model and the actual 360° snap node 15 connected together under wind load to verify the validity of the equivalent spring model.

[0101] Specifically, a verification device is used to test the three-way coupled deformation of the actual 360° interlocking nodes 15 under wind loads to verify the validity of the equivalent spring model;

[0102] Among them, the verification device includes a fixed seat 12 and a simulation frame 13 above the fixed seat 12. The simulation frame 13 is a door-shaped structure, and the lower ends of its two legs are bent and extended in opposite directions to form a connecting plate 14. The two panels of the 360° bite node 15 that are interlocked are connected to the connecting plate 14 by bolts respectively. The base plate of the support of the 360° bite node 15 is fixed on the fixed seat 12. The upper end of the simulation frame 13 is connected to the loading device. The loading device can drive the simulation frame 13 away from the fixed seat 12, so that the 360° bite node 15 produces three-way coupled deformation, and the validity of the equivalent spring model is verified by the load-displacement data of the loading device.

[0103] The fitted spring parameters are used for finite element model simulation and compared with the test results as shown in the figure. The results show that the two have a good fit, that is, the spring model can better reflect the mechanical properties of this type of panel node.

[0104] The wind resistance bearing capacity testing method of the metal panel of the present invention has the following advantages:

[0105] 1. Compared with the static wind-resistant test, this test method only needs to test the three-dimensional stiffness of the node. The test method is simple, convenient and economical.

[0106] 2. Compared with the contact method finite element simulation of the mechanical properties of the node, the simulation through equivalent spring parameters has higher computational efficiency.

[0107] 3. Simple operation, able to quickly complete the testing of a large number of specimens and improve testing efficiency.

[0108] 4. The implementation of automated testing reduces human errors and improves the reliability of testing.

[0109] 5. The test device can be improved and optimized according to actual needs and has broad application prospects.

[0110] The present invention establishes an equivalent spring model by considering the coupling effect between the three-way stiffness of the 360° interlocking node of the metal panel, and establishes the constitutive relationship of the equivalent spring. The constitutive relationship of the equivalent spring is analyzed by the load-displacement data of the test device, and the parameters characterizing the spring properties in the equivalent spring are obtained. The validity of the equivalent spring model is verified by comparing with the force conditions of the actual interlocking nodes. The present invention takes into account the coupling effect of the interlocking node, so that the test results of the interlocking node are more accurate and have higher precision, and can better evaluate the wind resistance of the metal panel, providing theoretical guidance for engineering design.

[0111] Although the embodiments of the present invention have been shown and described, it is apparent to those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and basis of the present invention. The scope of the present invention is defined by the appended claims and their equivalents. Therefore, the embodiments of the present invention are merely illustrative examples of the present invention. The embodiments of the present invention do not constitute limitations on the present invention from any point of view.

Claims

1. A method for establishing a 360° occlusal node equivalent spring model considering coupling effect, characterized in that: The following steps are included: a. Analyze the response characteristics of the 360° interlocking nodes actually connected together under wind loads; b. According to the response characteristics, the 360° bite node is decoupled into an equivalent spring combination structure, and an equivalent spring model is established considering the coupling effect; c. Establish the constitutive relationship of the equivalent spring combination structure based on the coupling effect; d. Obtain the load-displacement data of the 360° interlocking nodes actually connected together through the test device; e. Analyzing the constitutive relationship of the equivalent spring combination structure in the equivalent spring model according to the load-displacement data to obtain the spring properties of the equivalent spring combination structure; f. Input the spring properties of the equivalent spring into the equivalent spring model, and compare the response results of the equivalent spring model and the actual 360° interlocking nodes connected together under wind load to verify the validity of the equivalent spring model.

2. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 1, characterized in that: The 360° bite node comprises a horizontally arranged panel, and two ends of the panel are bent and extended upward to form a first bite portion and a second bite portion respectively; The first engaging portion includes a first vertical plate formed by bending and extending the panel upward, a first flat plate formed by bending and extending to a side away from the panel, a second vertical plate formed by bending and extending downward, a second flat plate formed by bending and extending to a side close to the panel, and a third vertical plate formed by bending and extending upward, and there are gaps between the first vertical plates, between the second vertical plates and the third vertical plates, and between the upper end of the third vertical plate and the first flat plate; The second engaging portion includes a fourth vertical plate formed by bending and extending the panel upward, a third flat plate formed by bending and extending toward a side close to the panel, and a fifth vertical plate formed by bending and extending downward; When the first engaging portion of the panel engages with the second engaging portion of the adjacent panel, the fifth vertical plate engages in the gap between the second vertical plate and the third vertical plate, the third flat plate engages in the gap between the upper end of the third vertical plate and the first flat plate, and the fourth vertical plate engages in the gap between the first vertical plate and the third vertical plate.

3. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 2, characterized in that: It also includes a support, which includes a horizontally arranged base plate, and a sixth vertical plate formed by bending and extending upward from one end of the base plate, a fourth flat plate formed by bending and extending to a side away from the base plate, a seventh vertical plate formed by bending and extending downward, a fifth flat plate formed by bending and extending to a side close to the base plate, and an eighth vertical plate formed by bending and extending upward. When engaged, the eighth vertical plate is engaged between the third vertical plate and the fifth vertical plate, the seventh vertical plate is engaged between the second vertical plate and the fifth vertical plate, the sixth vertical plate is engaged between the first vertical plate and the fourth vertical plate, and the fourth flat plate is engaged between the first flat plate and the third flat plate.

4. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 1, characterized in that: The equivalent spring combination structure comprises a multi-axis spring with two nodes and multiple degrees of freedom at the nodes, and the nodes can generate lateral displacement, vertical displacement or rotation angle under the action of force.

5. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 4, characterized in that: In step c, According to the tensile constitutive relation of common metal materials, the yield function and strengthening law of the multi-axis spring are proposed and expressed by the following formula: Where f is the spring force, b1, γ1, b2, γ2 are material parameters, a0 is the initial yield surface, a1 is the maximum subsequent yield surface, and m is the yield surface change rate. is the equivalent spring relative plastic displacement, where Calculated by the following formula, In the formula, is a tensor, representing the relative plastic displacement in each degree of freedom; From equations (1) and (2), it can be obtained that the constitutive relationship of the multi-axis spring when it is one degree of freedom is as follows: Combined with the spring displacement composition, we have: In the formula, u i is the relative displacement of the spring, K i is the spring stiffness in the i degree of freedom; Substituting equations (3) and (4) into equation (5), we can obtain the displacement-force relationship of the multi-axis spring under each degree of freedom, that is, Where b i and γ i Both represent the spring stiffness influence coefficients of the multi-axial spring with i degrees of freedom on the node performance, u1 and u i+1 is the relative displacement between two nodes of the multi-axial spring with corresponding degrees of freedom, f1 and f i+1 is the spring force of the multi-axis spring corresponding to the degree of freedom.

6. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 4, characterized in that: The testing device comprises a horizontal stiffness testing device, a vertical stiffness testing device and a rotational stiffness testing device, which are respectively used to test the horizontal stiffness, vertical stiffness and rotational stiffness of the multi-axis spring.

7. The method for establishing a 360° interlocking node equivalent spring model considering coupling effect according to claim 6, characterized in that: The horizontal stiffness testing device comprises two first clamping assemblies arranged opposite to each other, respectively used to clamp two side panels of a 360° bite node that are bitten together; Wherein, the first clamping assembly comprises a bottom plate and a back plate which are arranged relatively parallel, the back plate is connected to the bottom plate by bolts, and the panel is clamped between the bottom plate and the back plate; the two ends of the two bottom plates which are separated from each other are respectively formed with clamping ends, which are respectively used to connect with the loading device and fix the bottom plate; The loading device can drive the two first clamping components to move away from each other, so that the 360° bite node produces horizontal displacement, and the horizontal stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

8. The method for establishing a 360° interlocking node equivalent spring model considering coupling effect according to claim 6, characterized in that: The vertical stiffness testing device comprises a bracket with a door-shaped structure, wherein an extension plate is respectively provided at the lower end of two supporting feet of the bracket, the two extension plates extend in a direction close to each other, and a gap is provided between the ends of the two extension plates close to each other; a pressing plate is provided at the lower side of the two extension plates, the pressing plate is connected to the extension plate by bolts, and two panels of 360° interlocking nodes interlocked together are clamped between the pressing plate and the extension plate; A base is also fixedly provided below the bracket for fixing the support, wherein the base plate of the support is fixed to the base by bolts; a clamping end is provided at the upper end of the bracket for connecting with the loading device; The loading device can drive the bracket away from the base, causing vertical displacement between the support of the 360° interlocking node and the two interlocking panels. The vertical stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

9. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 4, characterized in that: The rotational stiffness testing device includes two rotating components arranged opposite to each other up and down, and the rotating components include a rotating shaft, rotating plates are vertically provided at both ends of the rotating shaft, and a clamping plate is installed between the same sides of the two rotating plates for clamping the panels of the 360° bite node that are bitten together; a counterweight is installed between the two rotating plates on the side away from the clamping plate; a connecting rod is also rotatably installed on the rotating shaft, and the connecting rods of the two rotating components are respectively used to connect and fix with the loading device, and the loading device can make the two rotating shafts move away from each other through the connecting rod, so that a rotation angle is generated between the two panels of the 360° bite node that are bitten together, and the rotational stiffness of the multi-axis spring is obtained through the load-displacement data of the loading device.

10. The method for establishing a 360° occlusal node equivalent spring model considering coupling effect according to claim 4, characterized in that: In step f, a verification device is used to test the three-way coupled deformation of the 360° interlocking nodes that are actually interlocked together under the action of wind loads, so as to verify the validity of the equivalent spring model; Among them, the verification device includes a fixed seat and a simulation frame above the fixed seat. The simulation frame is a door-shaped structure, and the lower ends of its two legs are bent and extended in opposite directions to form a connecting plate. The two panels of the 360° bite node that are interlocked together are connected to the connecting plate by bolts respectively. The base plate of the support of the 360° bite node is fixed on the fixed seat. The upper end of the simulation frame is connected to the loading device. The loading device can drive the simulation frame away from the fixed seat, so that the 360° bite node produces three-way coupled deformation. The validity of the equivalent spring model is verified by the load-displacement data of the loading device.

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