A modeling and finite element analysis method, system, equipment and medium for SMA stranded wire

Abstract

The present invention discloses a modeling and finite element analysis method, system, equipment, and medium for SMA stranded wires. The method includes: drawing the cross-sections of the center and side wires of a bundle, and drawing a spiral curve using the sum of the two cross-sectional radii. S2: scanning the cross-sections of the side wires of the bundle along the spiral curve direction and stretching the cross-sections of the center wires. S3: arranging the side wires in a circular array along the center wires with the center wire of the bundle as the array center to obtain a bundle model. S4: repeating S1 to S3: modeling the side wires with the spiral curve direction opposite to that of the bundle to obtain a bundle model. S5: bending the side wires with the bundle as the center so that the side wires rotate 360 ​​degrees around the bundle. S6: arranging the bent side wires in a circular array with the bundle as the array center to complete the SMA stranded wire modeling. This method requires relatively low professional knowledge and can save modeling time.

Description

Technical Field

[0001] The invention belongs to the field of SMA material analysis and relates to a modeling and finite element analysis method, system, equipment and medium for SMA strands. Background Art

[0002] In recent years, shape memory alloys (SMAs) have seen increasing application in civil engineering. Currently, SMA materials are mostly used in the form of wires and rods, but structural engineering often requires larger SMA components. SMA strands effectively amplify the advantages of wires, offering lower costs and greater structural flexibility compared to rods.

[0003] Currently, finite element analysis of SMA stranded wires typically uses simplified models, resulting in discrepancies between the results and the actual results. Due to the diverse structure of stranded wires, different strands require different modeling methods. For multi-strand stranded wires, parametric equations are often used for modeling, which is more difficult. Summary of the Invention

[0004] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a modeling and finite element analysis method, system, equipment and medium for SMA strands, which has low requirements for professional knowledge and can save modeling time.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A modeling method for an SMA stranded wire includes the following steps:

[0007] S1, draw the cross section of the middle wire and the side wire of the middle bundle, and draw the spiral curve with the sum of the two cross-sectional radii;

[0008] S2, scanning the cross section of the side wire of the middle bundle along the direction of the spiral curve and stretching the cross section of the middle wire;

[0009] S3, with the middle wire of the middle bundle as the array center, the side wires are arranged in a circular pattern along the middle wire to obtain the middle bundle model;

[0010] S4, repeat S1 to S3 to model the side beam, with the spiral curve direction opposite to that of the middle beam, to obtain the side beam model;

[0011] S5, with the center beam as the center, a bending operation is applied to the side beam so that the side beam rotates 360° around the center beam;

[0012] S6, with the middle bundle as the array center, the bent side bundles are arrayed in a circular pattern to complete the SMA strand modeling.

[0013] Preferably, S1 to S6 are all performed in SolidWorks.

[0014] Preferably, in S1, the height of the helical curve is the single lay pitch of the stranded wire, and the number of turns of the helical curve is the number of lay pitches.

[0015] Preferably, in S2, the tensile length of the middle filament cross section is a single lay length of the stranded wire.

[0016] Preferably, in S3, the number of circular arrays is equal to the number of edge wires.

[0017] Preferably, in S6, the number of circular arrays is equal to the number of side beams.

[0018] A finite element analysis method for an SMA strand includes the following steps:

[0019] S1, importing the model built by any of the above-mentioned SMA strand modeling methods into Workbench for modal analysis, inputting the constitutive relationship parameters of the SMA material, setting the contact mode to binding, and obtaining the lowest-order frequency;

[0020] S2, import into ABAQUS in step format for material assignment and meshing;

[0021] S3, create an explicit dynamics analysis step, with 10 times the inverse of the lowest-order frequency as the analysis step time;

[0022] S4, the contact adopts general contact, the tangential direction adopts penalty function calculation, and the normal direction is hard contact;

[0023] S5: Apply boundary conditions, select displacement loading, select Smooth step for the loading curve, and complete the finite element analysis.

[0024] A modeling system for an SMA stranded wire, comprising:

[0025] The spiral curve drawing module is used to draw the cross-section of the middle wire and the side wire of the middle bundle, and draw the spiral curve with the sum of the two cross-section radii;

[0026] The cross-section stretching module is used to scan the cross-section of the side wire of the middle bundle along the spiral curve direction and stretch the cross-section of the middle wire;

[0027] The middle bundle model building module is used to take the middle wire of the middle bundle as the array center, and arrange the side wires in a circular array along the middle wire to obtain the middle bundle model;

[0028] The side beam model building module is used to repeat the processes in the spiral curve drawing module, the cross-section stretching module and the center beam model building module to model the side beam. The direction of the spiral curve is opposite to that of the center beam to obtain the side beam model;

[0029] The rotation module is used to bend the side beams with the center beam as the center, so that the side beams rotate 360° around the center beam;

[0030] The SMA strand modeling module is used to perform circular arraying of the bent side strands with the middle strand as the array center to complete SMA strand modeling.

[0031] A computer device comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any one of the above-mentioned methods for modeling an SMA strand when executing the computer program.

[0032] A computer-readable storage medium stores a computer program, wherein the computer program, when executed by a processor, implements the steps of any one of the above-mentioned methods for modeling an SMA strand.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The modeling method of the present invention is simple. Currently, the modeling of multi-strand twisted wires is often done by creating curves through parametric equations, which often require multiple parameters, such as the twist pitch, twist angle, strand diameter, rope diameter and other parameters of the twisted wires, respectively creating the equations of the first spiral curve of the middle wire and the side wire of the middle bundle, and the equations of the second spiral curve of the middle wire and the side wire of the side bundle. This requires high professional knowledge for modeling, and the more strands of the wire rope there are, the more parametric equations need to be derived, and it takes a lot of time to complete the modeling. However, the present invention only requires the diameter of the single wire, the twist of the strand and the twisting method of the strand, and can establish a model of the multi-strand twisted wire according to the required stranded wire form. This requires less professional knowledge and can save modeling time.

[0035] In the finite element analysis method of the present invention, the contacts between the SMA strands are complex. When performing finite element analysis using statics, there are hundreds of surface contacts that need to be created, and the contact creation takes a long time. If the contact is set to universal contact, it is extremely difficult for the finite element analysis of the SMA strands to converge, and the calculation process will occupy a large amount of resources, and the finite element analysis will take up a long time. The present invention uses dynamic quasi-static analysis, and the finite element analysis calculation of the SMA strands is easy to converge. The calculation time can be accelerated by adjusting the mass scaling factor, and the calculation consumes less resources compared to static analysis. Due to the particularity of the stranded wire structure, the stranded wire models built by different software may not be able to be meshed in ABAQUS, and it is often necessary to use hypermesh software to mesh the stranded wire. The advantage of the present invention is that the built model can be directly meshed in ABAQUS without the need for meshing with other software. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a three-dimensional diagram of the middle wire and side wire model of the middle bundle built by the present invention;

[0037] Figure 2 This is a three-dimensional diagram of the 7×7 stranded wire model built by the present invention;

[0038] Figure 3 Flowchart of the finite element analysis method for SMA strands of the present invention;

[0039] Figure 4 The constitutive relationship of the SMA strand material used in the finite element analysis method of the present invention is:

[0040] Figure 5 This is a finite element analysis result diagram of the SMA strand of the present invention. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0042] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the accompanying drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0044] The refined modeling method of the SMA stranded wire of the present invention comprises the following steps:

[0045] Step 1: Draw the middle wire and side wire sections in SolidWorks, and draw the spiral curve with the sum of the two section radii.

[0046] The height of the helical curve is the single lay pitch of the stranded wire, and the number of turns of the helical curve is the number of lay pitches.

[0047] Step 2: Scan the side wire section along the spiral curve direction and stretch the middle wire section. The stretching length is the single lay length of the stranded wire.

[0048] Step 3: With the middle wire as the array center, arrange the side wires in a circular pattern along the middle wire. The number of circular patterns is equal to the number of side wires. This will give the middle bundle model.

[0049] Step 4: Edge beam modeling: Same as steps 1, 2, and 3, but with the spiral curve in the opposite direction. This will create an edge beam model.

[0050] Step 5: With the center beam as the center, bend the side beams so that they rotate 360° around the center beam.

[0051] Step 6: With the center beam as the center, perform a circular array on the bent side beams. The number of circular arrays is equal to the number of side beams to complete the modeling.

[0052] The finite element analysis method of the SMA strand of the present invention comprises the following steps:

[0053] Step 1: Import the model built using any of the above SMA strand modeling methods into Workbench for modal analysis. Enter the SMA material constitutive relationship parameters, set the contact mode to bonded, and obtain the lowest-order frequency.

[0054] Step 2: Import into ABAQUS in step format for material assignment and mesh division.

[0055] Step 3: Create an explicit dynamics analysis step with a step time of 10 times the inverse of the lowest-order frequency.

[0056] Arrangement 4: General contact is used for contact, penalty function is used for tangential direction, and hard contact is used for normal direction.

[0057] Step 5: Apply boundary conditions, select displacement loading, select Smooth step for the loading curve, and complete the finite element analysis.

[0058] Specific examples of the present invention are given below:

[0059] Following the above modeling method, complete the SMA stranded wire modeling through the following specific steps, taking the 7×7 structure as an example:

[0060] 1. Draw the cross-section of the middle wire and the side wire of the middle bundle. The circle radius is 0.5mm. With a radius of 1.0mm, draw a spiral curve with the height and number of turns. The height is a lay length of 160mm, the number of turns is equal to the lay length, which is 1 turn, and the direction is clockwise.

[0061] 2. Scan the drawn middle bundle side wire section along the spiral curve path to obtain the middle bundle side wire. The middle wire of the middle bundle is obtained by stretching the cross section by 160mm.

[0062] 3. With the middle wire of the middle bundle as the array center, the side wires are arranged in a circular array with an array angle of 360° and an array number of 6 to obtain the stranded wire middle bundle model.

[0063] 4. The modeling method is the same as that of the stranded wire mid-bundle model, with the spiral curve direction set to counterclockwise to establish the stranded wire side bundle model.

[0064] 5. Bend the side bundle model so that the stranded side bundle rotates 360° around the center bundle. The resulting model is as follows: Figure 1 shown.

[0065] 6. With the middle bundle as the array center, the bent strand side bundle model is arrayed in a circular pattern with 6 arrays and an array angle of 360° to obtain a refined finite element model of the 7×7 SMA strand, as shown in the figure. Figure 2 shown.

[0066] From the above finite element analysis process, such as Figure 3 The specific analysis steps are as follows:

[0067] The constitutive relationship of SMA material used in finite element analysis is as follows: Figure 4 As shown, the constitutive relationship is determined by the following parameters: σ s，AM represents the martensitic transformation starting stress, σ f，AM represents the end stress of martensitic transformation, σ s，MA represents the stress at the start of austenite transformation, σ f，MA represents the end stress of austenite transformation, ε L represents the maximum phase transformation strain, E A and E M represents the initial elastic modulus and martensite elastic modulus.

[0068] 1. Modal analysis: Import the SMA stranded wire model into Workbench, input the constitutive relationship parameters of the SMA material, change the contact type to binding, apply the constraint condition of one end fixed and the other end allowing axial displacement, perform modal analysis, and obtain the lowest-order frequency of the structure to be 95 Hz.

[0069] 2. Meshing and material assignment: Import the model into ABAQUS in step format to complete meshing, and assign material parameters using the constitutive relationship built into ABAQUS.

[0070] 3. Analysis step settings: Set the analysis step to display dynamics, and the analysis step time to 0.1s, which is 10 times the inverse of the lowest-order frequency. Set the mass scaling factor to 400.

[0071] 4. Contact settings: The contact is set to general contact, the tangential direction is calculated using a penalty function, the friction coefficient is 0.1, and the normal direction is hard contact.

[0072] 5. Boundary conditions and loading method: The constraint method is to fix one end and allow axial displacement at the other end. Displacement loading is adopted, the strain amplitude is 8%, and the loading curve is Smooth step.

[0073] 6. Submit the work to complete the finite element analysis. The obtained SMA strand hysteresis curve is as follows: Figure 5 shown.

[0074] The following are device embodiments of the present invention, which can be used to perform the method embodiments of the present invention. For details not disclosed in the device embodiments, please refer to the method embodiments of the present invention.

[0075] In another embodiment of the present invention, a modeling system for an SMA strand is provided. The modeling system for an SMA strand can be used to implement the above-mentioned modeling method for an SMA strand. Specifically, the modeling system for an SMA strand includes a spiral curve drawing module, a cross-section stretching module, a mid-beam modeling module, a side-beam modeling module, a rotation module, and an SMA strand modeling module.

[0076] Among them, the spiral curve drawing module is used to draw the cross-sections of the middle wire and the side wire of the middle bundle, and draw the spiral curve with the sum of the two cross-section radii.

[0077] The cross-section stretching module is used to scan the cross-section of the center bundle edge wire along the spiral curve direction and stretch the cross-section of the center wire.

[0078] The mid-bundle model building module is used to take the middle wire of the mid-bundle as the array center, and to arrange the side wires in a circular array along the middle wire to obtain the mid-bundle model.

[0079] The side beam model building module is used to repeat the processes in the spiral curve drawing module, the cross-section stretching module and the center beam model building module to model the side beam. The direction of the spiral curve is opposite to that of the center beam to obtain the side beam model.

[0080] The rotation module is used to bend the side beams with the center beam as the center, so that the side beams rotate 360° around the center beam.

[0081] The SMA strand modeling module is used to perform circular arraying of the bent side strands with the middle strand as the array center to complete the SMA strand modeling.

[0082] In another embodiment of the present invention, a terminal device is provided, the terminal device including a processor and a memory, the memory being used to store a computer program, the computer program including program instructions, and the processor being used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or may be other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGAs), or a processor that is ... GateArray, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding function; the processor described in the embodiment of the present invention can be used for the operation of the SMA strand modeling method, including: S1, drawing the cross-section of the middle wire and the side wire of the middle bundle, and drawing a spiral curve with the sum of the two cross-section radii; S2, scanning the cross-section of the side wire of the middle bundle along the direction of the spiral curve, and stretching the cross-section of the middle wire; S3, with the middle wire of the middle bundle as the array center, the side wires are arranged in a circular array along the middle wire to obtain a middle bundle model; S4, repeating S1 to S3, modeling the side bundle, the spiral curve direction is opposite to that of the middle bundle, and obtaining a side bundle model; S5, with the middle bundle as the center, applying a bending operation to the side bundle so that the side bundle rotates 360° around the middle bundle; S6, with the middle bundle as the array center, the bent side bundle is arranged in a circular array to complete the SMA strand modeling.

[0083] In another embodiment, the present invention further provides a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and, of course, the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space. These instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory.

[0084] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the modeling method of the SMA stranded wire in the above embodiment; one or more instructions in the computer-readable storage medium are loaded by the processor and the following steps are executed: S1, draw the cross-section of the middle wire and the side wire of the middle bundle, and draw a spiral curve with the sum of the radii of the two cross-sections; S2, scan the cross-section of the side wire of the middle bundle along the direction of the spiral curve, and stretch the cross-section of the middle wire; S3, with the middle wire of the middle bundle as the array center, arrange the side wires in a circular array along the middle wire to obtain a middle bundle model; S4, repeat S1 to S3, model the side bundle, and the direction of the spiral curve is opposite to that of the middle bundle to obtain a side bundle model; S5, with the middle bundle as the center, apply a bending operation to the side bundle so that the side bundle rotates 360° around the middle bundle; S6, with the middle bundle as the array center, arrange the bent side bundle in a circular array to complete the modeling of the SMA stranded wire.

[0085] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0086] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0087] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0088] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0089] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0090] It should be understood that the above description is for illustrative purposes only and is not intended to be limiting. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the preceding claims and the full scope of equivalents to which such claims are entitled. For the purpose of completeness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein from the preceding claims is not a disclaimer of such subject matter, nor should it be considered that the applicants did not consider such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A modeling method for an SMA stranded wire, characterized in that: The following processes are included: S1, draw the cross section of the middle wire and the side wire of the middle bundle, and draw a spiral curve with the sum of the two cross section radii; the height of the spiral curve is the single lay pitch of the stranded wire, and the number of turns of the spiral curve is the number of lay pitches; S2, scan the cross section of the side wire of the middle bundle along the direction of the spiral curve and stretch the cross section of the middle wire; the stretched length of the cross section of the middle wire is the single lay length of the stranded wire; S3, with the middle wire of the middle bundle as the array center, the side wires are arrayed in a circular pattern along the middle wire to obtain the middle bundle model; the number of circular patterns is equal to the number of side wires; S4, repeat S1 to S3 to model the side beam, with the spiral curve direction opposite to that of the middle beam, to obtain the side beam model; S5, with the center beam as the center, a bending operation is applied to the side beam so that the side beam rotates 360° around the center beam; S6: With the middle bundle as the array center, the bent side bundles are arrayed in a circular pattern. The number of circular patterns is equal to the number of side bundles, completing the SMA strand modeling.

2. The SMA strand modeling method according to claim 1, wherein: S1 to S6 were all performed in SolidWorks.

3. A finite element analysis method for SMA strands, characterized in that: The following processes are included: S1, importing the model built by the SMA strand modeling method according to any one of claims 1-2 into Workbench for modal analysis, inputting the constitutive relationship parameters of the SMA material, setting the contact mode to binding, and obtaining the lowest-order frequency; S2, import into ABAQUS in step format for material assignment and meshing; S3, create an explicit dynamics analysis step, with 10 times the inverse of the lowest-order frequency as the analysis step time; S4, the contact adopts general contact, the tangential direction adopts penalty function calculation, and the normal direction is hard contact; S5: Apply boundary conditions, select displacement loading, select Smooth step for the loading curve, and complete the finite element analysis.

4. A modeling system for an SMA strand, characterized in that: include: The spiral curve drawing module is used to draw the cross-section of the middle wire and the side wire of the middle bundle. The spiral curve is drawn with the sum of the two cross-section radii. The height of the spiral curve is the single lay pitch of the stranded wire, and the number of turns of the spiral curve is the number of lay pitches. The cross-section stretching module is used to scan the cross-section of the side wires in the middle bundle along the spiral curve direction and stretch the cross-section of the middle wire; the stretching length of the middle wire cross-section is the single lay length of the stranded wire; The middle bundle model building module is used to form a circular array of the side wires along the middle wire with the middle wire of the middle bundle as the array center to obtain the middle bundle model; the number of circular arrays is equal to the number of side wires; The side beam model building module is used to repeat the processes in the spiral curve drawing module, the cross-section stretching module and the center beam model building module to model the side beam. The direction of the spiral curve is opposite to that of the center beam to obtain the side beam model; The rotation module is used to bend the side beams with the center beam as the center, so that the side beams rotate 360° around the center beam; The SMA strand modeling module is used to perform circular arraying of the bent side bundles with the middle bundle as the array center. The number of circular arrays is equal to the number of side bundles, completing the SMA strand modeling.

5. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the SMA strand modeling method according to any one of claims 1 to 2 are implemented.

6. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the SMA strand modeling method according to any one of claims 1 to 2 are implemented.

Images