Simulation analysis method for shape memory alloy heat engine

Abstract

This invention discloses a simulation analysis method for shape memory alloy heat engines. The method involves performing kinematic simulation analysis on the shape memory alloy heat engine using motion analysis software to create a three-dimensional structural model. The three-dimensional structural model is then analyzed using finite element method (FEM) 3D transient analysis to obtain the torque curve of the permanent magnet. A thermal deformation experiment is conducted on the three-dimensional structural model to generate the force-displacement function relationship of the shape memory alloy spring. A virtual prototype is constructed and simulated using multibody dynamics analysis to optimize the three-dimensional structural model. Finally, the virtual prototype is simulated using FEM statics analysis to verify the strength and stability of the three-dimensional structural model. This method solves the problem in related technologies where theoretical simulations relying solely on dynamic formula derivation or MATLAB simulations are difficult to apply to actual working environments, and sometimes even require physical fabrication, leading to long development cycles and high costs.

Description

Technical Field

[0001] This invention relates to the field of energy conversion technology, and more particularly to a simulation analysis method for shape memory alloy heat engines. Background Technology

[0002] Shape memory alloy (SME) heat engines utilize the reversible correlation of SME materials under temperature changes to achieve thermal energy conversion. Waste heat recovery technology, as a sustainable energy solution, has received widespread attention from researchers and industry. SME heat engines show promising application prospects in waste heat recovery and utilization. For example, patent application number 202410655374.0 discloses a SME waste heat conversion device. When the SME is heated and deformed, it drives one end of a cable assembly to move along the deformation direction of the SME, and drives a rotating mechanism to rotate around a shaft. When the rotating mechanism rotates close to a permanent magnet, the permanent magnet provides a repulsive force to the rotating mechanism in the opposite direction, thus converting thermal energy into mechanical energy.

[0003] Currently, most simulations of shape memory alloy heat engines rely on the derivation of kinetic formulas or MATLAB simulations. These simulations are theoretical simulations that cannot be applied to actual working environment conditions. Sometimes, it is even necessary to verify them by directly building physical prototypes.

[0004] Both the research and development cycle and the cost require a considerable amount of time and money. This is detrimental to product development and the feasibility study of the early stages of development. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a simulation analysis method for shape memory alloy thermoengines that can shorten the development cycle and reduce R&D costs.

[0006] The technical solution adopted by this invention to solve its technical problem is as follows:

[0007] A simulation analysis method for shape memory alloy heat engines, the simulation analysis method comprising the following steps:

[0008] S1. The kinematic simulation analysis of the shape memory alloy thermoengine is performed using motion analysis software, and a three-dimensional structural model is obtained by three-dimensional modeling.

[0009] S2. The three-dimensional structural model was analyzed using the finite element method in 3D transient analysis to obtain the torque curve of the permanent magnet;

[0010] S3. By conducting thermal deformation experiments on the three-dimensional structural model, the force-displacement function relationship of the shape memory alloy spring is generated;

[0011] S4. Based on the permanent magnet torque curve and force-displacement function obtained in steps S2 and S3, construct a virtual prototype, perform simulation analysis on the virtual prototype using multibody dynamics analysis, and optimize the three-dimensional structural model based on the simulation analysis results.

[0012] S5. The virtual prototype is simulated and analyzed using the finite element static analysis method to verify the strength and stability of the three-dimensional structural model.

[0013] In a preferred embodiment of the present invention, step S1 includes performing kinematic simulation analysis on the permanent magnet drive mechanism, the shape memory alloy spring transmission mechanism, and the base of the shape memory alloy thermoengine.

[0014] In a preferred embodiment of the present invention, in step S1, the motion analysis software is SOLIDWORKS; step S1 further includes the following steps:

[0015] S101. Use SOLIDWORKS to perform three-dimensional modeling of the shape memory alloy thermoengine to obtain a three-dimensional structural model;

[0016] The steps of 3D modeling include: designing the distribution and location of bearings and anchor points;

[0017] Design the parameter values ​​for density, Young's modulus, Poisson's ratio, center of mass, and moment of inertia;

[0018] Design kinematic pairs and their coordination and constraint relationships;

[0019] Kinematic analysis was performed on the permanent magnet drive mechanism, the shape memory alloy spring transmission mechanism, and the base to determine the relative movement trajectory between the permanent magnet drive mechanism and the shape memory alloy spring transmission mechanism.

[0020] In a preferred embodiment of the present invention, step S1 further includes the following step:

[0021] S102. The ropes used for connecting the shape memory alloy springs in the shape memory alloy thermoelectric engine are modeled using AdamsMachinery's rope system;

[0022] The modeling steps include: setting up connecting components with anchor points;

[0023] Set the width, depth, radius, and angle attributes of the pulley;

[0024] Set the contact parameters, including Hertz and the coefficient of friction;

[0025] Plan the layout parameters of the pulleys, including the rotation axis, position, diameter, and Angular Mis-Alignment of the pulleys;

[0026] Set the rope density, Young's modulus, and damping coefficient.

[0027] In a preferred embodiment of the present invention, in step S2, the torque magnitude of the permanent magnet drive mechanism is analyzed in 3D transients using ANSYS Maxwell to simulate the interaction force generated between the large permanent magnet and the small permanent magnet when the small permanent magnet rotates, thereby obtaining the permanent magnet torque curve.

[0028] In a preferred embodiment of the present invention, step S3 includes measuring the contraction force and displacement relationship of a two-way shape memory alloy spring after heating and then cooling, and then performing interpolation fitting calculations using MATLAB to generate a force-displacement function relationship for the shape memory alloy spring.

[0029] In a preferred embodiment of the present invention, the force-displacement function relationship of the shape memory alloy spring is as follows:

[0030]

[0031] In a preferred embodiment of the present invention, in step S4, the three-dimensional structural model, the torque curve of the permanent magnet, and the force-displacement function relationship of the shape memory alloy spring are exported to form a neutral file, and the gravitational acceleration, material density, friction force, and constraint relationship are set to construct a virtual prototype, which is then imported into the ADAMS multibody dynamics analysis software for joint simulation analysis.

[0032] In a preferred embodiment of the present invention, step S4 further includes the following step:

[0033] S401. Construct a virtual prototype based on actual working conditions, including constructing fixed joints, sliding joints, rotary joints, and contact relationships. The construction steps include:

[0034] A fixing pair is provided between one end of the shape memory alloy spring and the first support plate;

[0035] A sliding pair is set between the other end of the shape memory alloy spring and the second support plate, with a friction coefficient of 0.2.

[0036] A rotary pair is set between the first support plate and the rotating rod, with a friction coefficient of 0.2.

[0037] A solid-to-solid contact is set between the second and third support plates, with the normal force being collision, stiffness being 1.0E+05, force exponent being 2.2, damping coefficient being 2.2, and penetration depth being 0.1mm.

[0038] Let the gravitational acceleration in the system be 9806.65 mm / s². 2 ;

[0039] S402. The main bearing of the virtual prototype is constructed using the bearing module in Adams Machinery. The construction steps include:

[0040] Select a single-row deep groove ball bearing, with the bearing housing set to ground in ADAMS. Set radial and axial constraints, bearing clearance to C0, radial and bending damping coefficients to 0.1, and axial damping coefficient to 0.2.

[0041] In a preferred embodiment of the present invention, in step S5, the virtual prototype is subjected to static analysis using ANSYS Workbench to evaluate the deformation characteristics of the material under stress and to analyze the strain condition under maximum stress, thereby verifying its strength and stability.

[0042] The beneficial effects of this invention are: it provides a simulation analysis method for shape memory alloy heat engines, solving the problems of long development cycles and high costs associated with theoretical simulations using kinetic formulas or MATLAB simulations that cannot incorporate actual working environment conditions. Furthermore, this joint simulation analysis method uses a virtual prototype to predict and accurately analyze various data from actual operation, and performs dynamic analysis, calculation, and optimization design. This shortens the development cycle, reduces R&D costs, and facilitates future improvements and verification. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the simulation analysis method of the present invention for shape memory alloy thermoelectric engines;

[0044] Figure 2 This is a schematic diagram of the three-dimensional structural model of the shape memory alloy heat engine in this invention;

[0045] Figure 3 This is a torque curve diagram of the permanent magnet in this invention;

[0046] Figure 4 This is the magnetic induction intensity vector cloud map in this invention;

[0047] Figure 5 This is a cloud map of the magnetic induction intensity amplitude in this invention;

[0048] Figure 6 This is a schematic diagram of the displacement of the shape memory alloy on the left side of the shape memory alloy thermoelectric generator in this invention;

[0049] Figure 7 This is a schematic diagram of the displacement of the shape memory alloy on the right side of the shape memory alloy thermoelectric generator in this invention;

[0050] Figure 8 This is a schematic diagram of the simulated torque drive of the virtual prototype in this invention;

[0051] Figure 9 This is a motion trajectory diagram of the transmission mechanism of the shape memory alloy thermoelectric engine in this invention in the YZ plane;

[0052] Figure 10 This is a diagram showing the motion trajectory of the anchor point 1 bound to the SMA in the X direction based on the rotation of the transmission mechanism of the shape memory alloy thermoelectric engine in the YZ plane.

[0053] Figure 11 This is a diagram showing the motion trajectory of the transmission mechanism of the shape memory alloy thermoelectric engine in the present invention in the YZ plane and in the XY plane (including the Z-axis depth);

[0054] Figure 12 This is a schematic diagram of the deformation of the transmission component under maximum stress in this invention;

[0055] Figure 13 This is a cloud diagram of the safety factor of the bearing housing under maximum stress in this invention.

[0056] Figure 14 This is a schematic diagram of the base deformation under maximum stress in this invention;

[0057] Figure 15 This is a flowchart of the simulation analysis method for shape memory alloy thermoengines according to the present invention.

[0058] In the figure: 1. Permanent magnet drive mechanism; 2. Shape memory alloy spring transmission mechanism; 3. Base; 4. Shape memory alloy spring; 5. First support plate; 6. Second support plate; 7. Third support plate. Detailed Implementation

[0059] The technical solutions in the embodiments of the present invention will now be clearly and completely described in conjunction with the accompanying drawings.

[0060] Reference Figures 1 to 15 A simulation analysis method for shape memory alloy heat engines, characterized in that the simulation analysis method includes the following steps:

[0061] S1. The kinematic simulation analysis of the shape memory alloy thermoengine is performed using motion analysis software, and a three-dimensional structural model is obtained by three-dimensional modeling.

[0062] S2. The three-dimensional structural model was analyzed using the finite element method in 3D transient analysis to obtain the torque curve of the permanent magnet;

[0063] S3. By conducting thermal deformation experiments on the three-dimensional structural model, the force-displacement function relationship of the shape memory alloy spring is generated;

[0064] S4. Based on the permanent magnet torque curve and force-displacement function obtained in steps S2 and S3, construct a virtual prototype, perform simulation analysis on the virtual prototype using multibody dynamics analysis, and optimize the three-dimensional structural model based on the simulation analysis results.

[0065] S5. The virtual prototype is simulated and analyzed using the finite element static analysis method to verify the strength and stability of the three-dimensional structural model.

[0066] Through the steps described above, using co-simulation virtual prototyping technology, various data from actual operation can be predicted and accurately analyzed, enabling dynamic analysis, calculation, and optimization design. This simulation analysis method can shorten the development cycle and reduce R&D costs, and is beneficial for future improvements and verification. Furthermore, most shape memory alloy heat engines use kinetic formula derivation or MATLAB simulations for simulation, which are theoretical simulations that cannot be applied to actual working environment conditions. This requires significant time and expense, both in terms of development time and cost, hindering product development and feasibility studies in the early stages. Therefore, this simulation analysis method for shape memory alloy heat engines can effectively solve the problems in existing technologies and achieve corresponding results.

[0067] In step S1 of this scheme, kinematic simulation analysis is performed on the permanent magnet drive mechanism 1, the shape memory alloy spring transmission mechanism 2, and the base 3 of the shape memory alloy thermoelectric engine, and 3D modeling is performed by setting the dimensions and structure according to actual working conditions. The kinematic analysis software is SOLIDWORKS; step S1 also includes the following steps:

[0068] S101. Use SOLIDWORKS to perform three-dimensional modeling of the shape memory alloy thermoengine to obtain a three-dimensional structural model;

[0069] The steps of 3D modeling include: designing the distribution and location of bearings and anchor points;

[0070] Design the parameter values ​​for density, Young's modulus, Poisson's ratio, center of mass, and moment of inertia;

[0071] Design kinematic pairs and their coordination and constraint relationships;

[0072] Kinematic analysis was performed on the permanent magnet drive mechanism 1, the shape memory alloy spring transmission mechanism 2, and the base 3 to determine the relative movement trajectory between the permanent magnet drive mechanism 1 and the shape memory alloy spring transmission mechanism 2. The permanent magnet drive mechanism 1 includes a shape memory alloy spring, a first support plate 5, a second support plate 6, and a third support plate 7.

[0073] After the 3D structural model is built, kinematic simulation is used to verify and optimize the design of the 3D structural model to ensure its rationality. At the same time, it is exported as a neutral file for subsequent finite element analysis and virtual prototype simulation.

[0074] This solution S1 also includes the following steps:

[0075] S102. The rope used to connect the shape memory alloy spring 4 in the shape memory alloy thermoelectric engine is modeled using AdamsMachinery's rope system;

[0076] The modeling steps include: setting up connecting components with anchor points;

[0077] Set the width, depth, radius, and angle attributes of the pulley;

[0078] Set the contact parameters, including Hertz and the coefficient of friction;

[0079] Plan the layout parameters of the pulleys, including the rotation axis, position, diameter, and Angular Mis-Alignment of the pulleys;

[0080] Set the rope density, Young's modulus, and damping coefficient.

[0081] In step S2 of this scheme, the torque of the permanent magnet drive mechanism 1 is analyzed in 3D transiently using ANSYS Maxwell. The interaction force generated between the large permanent magnet and the small permanent magnet when the small permanent magnet rotates is simulated, thereby obtaining the permanent magnet torque curve.

[0082] The specific steps include: establishing a model through SOLIDWORKS using ANSYS MAXWELL co-simulation; assigning material properties to the model; meshing; applying boundary conditions; setting motion parameters and transient solver parameters; and performing a feasibility check. The model dimensions are analyzed and modified based on the actual motion conditions. The Transient solution type is set in Maxwell 3D. The two groups of four permanent magnets are made of NdFe35 material. A Cartesian coordinate system is used to create a Region around the entire permanent magnet section with a Radius of 200mm and a Height of 150mm. Bands are assigned using Rotation motion.

[0083] The analysis is set to perform 1000 steps per second; a feasibility check is performed, where excitations are not required due to the use of NdFe35 permanent magnet material; the permanent magnet mesh is set to a maximum element length of 10 mm, the region mesh to a maximum number of additional elements of 10000, and Slider 7 is used for the band mesh.

[0084] We selected B vector and Mag B from the Fields analysis, as well as Torque Plot from the Results, and then performed a comprehensive solution analysis on them.

[0085] By observing B vector and Mag B, the model was further modified and improved to obtain a satisfactory permanent magnet torque curve. The permanent magnet torque curve was exported as a neutral file for co-simulation analysis.

[0086] In step S3 of this scheme, the contraction force and displacement relationship of the two-way shape memory alloy spring 4 after heating and then cooling are measured. Then, interpolation fitting calculations are performed using MATLAB to generate the force-displacement function relationship of the shape memory alloy spring. The force-displacement function relationship of the shape memory alloy spring is as follows:

[0087]

[0088] In step S4 of this scheme, the three-dimensional structural model, the torque curve of the permanent magnet, and the functional relationship between force and displacement are exported to form a neutral file. Gravitational acceleration, material density, friction force, and constraint relationships are set to construct a virtual prototype, which is then imported into the ADAMS multibody dynamics analysis software for joint simulation analysis.

[0089] S4 of this scheme also includes the following steps:

[0090] S401. Construct a virtual prototype based on actual working conditions, including constructing fixed joints, sliding joints, rotary joints, and contact relationships. The construction steps include:

[0091] A fixing pair is provided between one end of the shape memory alloy spring 4 and the first support plate 5;

[0092] A sliding pair is provided between the other end of the shape memory alloy spring 4 and the second support plate 6, with a friction coefficient of 0.2.

[0093] A rotary pair is set between the first support plate 5 and the rotating rod, with a friction coefficient of 0.2.

[0094] A solid-to-solid contact is set between the second support plate 6 and the third support plate 7, with the normal force being collision, stiffness being 1.0E+05, force exponent being 2.2, damping coefficient being 2.2, and penetration depth being 0.1mm;

[0095] Let the gravitational acceleration in the system be 9806.65 mm / s². 2 ;

[0096] S402. The main bearing of the virtual prototype is constructed using the bearing module in Adams Machinery. The construction steps include:

[0097] Select a single-row deep groove ball bearing (SKF 618 / 8), with the bearing housing set to ground in ADAMS. Set radial and axial constraints, bearing clearance to C0, radial and bending damping coefficients to 0.1, and axial damping coefficient to 0.2.

[0098] This process involves importing the force-displacement function relationship of the shape memory alloy spring into ADAMS, importing a neutral file of the permanent magnet torque curve from Ansys Maxwell into ADAMS, and using ADAMS data units to create SPLINE curves and system unit variables. The driving mode is set to force-driven, applying torque by calling variables and the SPLINE curve, thus performing joint simulation analysis. Finally, based on the permanent magnet torque curve, the force-displacement function relationship of the shape memory alloy spring, and the results of static analysis, a multibody dynamics simulation analysis is performed on the entire virtual prototype. The simulation analysis results are used for optimization design to obtain a reasonable three-dimensional structural model, thereby verifying its rationality and feasibility.

[0099] In step S5 of this scheme, ANSYS Workbench is used to perform static analysis on the virtual prototype to evaluate the deformation characteristics of the material under stress and analyze the strain condition under maximum stress, thereby verifying the strength and stability of the three-dimensional structural model.

[0100] The main focus was on using ANSYS Workbench to perform static analysis on the shape memory alloy spring transmission mechanism 2, with particular attention to the strain at key locations under maximum stress. Material property analysis was also conducted on key components (such as bearings and transmission mechanisms) in the 3D structural model to verify their strength and stability under maximum load. If the simulation results showed excessive strain or structural inadequacy, the design was adjusted accordingly. The relevant simulation results are as follows:

[0101] like Figure 10Static simulation analysis revealed that the largest deformation occurred at the point where a 2N force was applied. The red to blue lines represent the distribution of deformation from largest to smallest. The black box in the figure represents the initial position, after which motion occurred due to the applied force. Observing the deformation effect in conjunction with the motion, it was found that the fixed rods of the four shape memory alloy springs 4 underwent some deformation during rotation, but the deformation was small and did not affect the actual motion.

[0102] like Figure 11 A safety factor analysis was conducted on the bearing housing under a maximum stress of 3.1 N in the Y direction. A smaller safety factor indicates greater danger; the theoretical minimum must be greater than 1. Civilian designs typically have a safety factor of 1.2-2, while military or higher-precision products may require at least 5. Safety factors were obtained for both the Y and Z directions under stress, both being 15, far greater than 1, indicating excellent safety.

[0103] like Figure 12 Simulation analysis of base 3 revealed that the maximum overall deformation under maximum stress was only 0.023 mm. This deformation is very small and acceptable within a safe range. The final simulation results show that the optimized device structure can withstand the stresses of actual operation and ensure safe operation.

[0104] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A simulation analysis method for shape memory alloy thermoengines, characterized in that, The simulation analysis method includes the following steps: S1. The kinematic simulation analysis of the shape memory alloy thermoengine is performed using motion analysis software, and a three-dimensional structural model is obtained by three-dimensional modeling. S2. The three-dimensional structural model was analyzed using the finite element method in 3D transient analysis to obtain the torque curve of the permanent magnet; S3. By conducting thermal deformation experiments on the three-dimensional structural model, the force-displacement function relationship of the shape memory alloy spring is generated; S4. Based on the permanent magnet torque curve and force-displacement function obtained in steps S2 and S3, construct a virtual prototype, perform simulation analysis on the virtual prototype using multibody dynamics analysis, and optimize the three-dimensional structural model based on the simulation analysis results. S5. The virtual prototype is simulated and analyzed using the finite element static analysis method to verify the strength and stability of the three-dimensional structural model; In step S1, kinematic simulation analysis is performed on the permanent magnet drive mechanism (1), the shape memory alloy spring transmission mechanism (2), and the base (3) of the shape memory alloy thermoelectric engine. In step S2, the torque of the permanent magnet drive mechanism (1) is analyzed in 3D transients using ANSYS Maxwell to simulate the interaction force between the large permanent magnet and the small permanent magnet when the small permanent magnet rotates, thereby obtaining the permanent magnet torque curve. In step S3, the contraction force and displacement relationship of the two-way shape memory alloy spring (4) after heating and cooling are measured, and then the force-displacement function relationship of the shape memory alloy spring is generated by interpolation fitting calculation through MATLAB. In step S4, the three-dimensional structural model, the torque curve of the permanent magnet, and the force-displacement function relationship of the shape memory alloy spring are exported to form a neutral file. Gravitational acceleration, material density, friction force, and constraint relationships are set to construct a virtual prototype, which is then imported into the ADAMS multibody dynamics analysis software for joint simulation analysis.

2. The simulation analysis method for shape memory alloy thermoengines according to claim 1, characterized in that, In step S1, the motion analysis software is SOLIDWORKS; step S1 also includes the following steps: S101. Use SOLIDWORKS to perform three-dimensional modeling of the shape memory alloy thermoengine to obtain a three-dimensional structural model; The steps of 3D modeling include: designing the distribution and location of bearings and anchor points; Design the parameter values ​​for density, Young's modulus, Poisson's ratio, center of mass, and moment of inertia; Design kinematic pairs and their coordination and constraint relationships; Kinematic analysis was performed on the permanent magnet drive mechanism (1), the shape memory alloy spring transmission mechanism (2) and the base (3) to determine the relative movement trajectory of the permanent magnet drive mechanism (1) and the shape memory alloy spring transmission mechanism (2).

3. The simulation analysis method for shape memory alloy heat engines according to claim 1, characterized in that, S1 further includes the following steps: S102. The rope used to connect the shape memory alloy spring (4) in the shape memory alloy thermoelectric machine is modeled using AdamsMachinery's rope system; The modeling steps include: setting up connecting components with anchor points; Set the width, depth, radius, and angle attributes of the pulley; Set the contact parameters, including Hertz and the coefficient of friction; Plan the layout parameters of the pulleys, including the rotation axis, position, diameter, and Angular Mis-Alignment of the pulleys; Set the rope density, Young's modulus, and damping coefficient.

4. The simulation analysis method for shape memory alloy thermoengines according to claim 1, characterized in that, The force-displacement function relationship of the memory alloy spring is as follows:

5. The simulation analysis method for shape memory alloy thermoengines according to claim 1, characterized in that, S4 also includes the following steps: S401. Construct a virtual prototype based on actual working conditions, including constructing fixed joints, sliding joints, rotary joints, and contact relationships. The construction steps include: A fixing pair is provided between one end of the shape memory alloy spring (4) and the first support plate (5); A sliding pair is provided between the other end of the shape memory alloy spring (4) and the second support plate (6), with a friction coefficient of 0.

2. A rotary pair is set between the first support plate (5) and the rotating rod, with a friction coefficient of 0.

2. A solid-to-solid contact is set between the second support plate (6) and the third support plate (7), with the normal force being collision, stiffness being 1.0E+05, force index being 2.2, damping coefficient being 2.2, and penetration depth being 0.1mm; Let the gravitational acceleration in the system be 9806.65 mm / s². 2 ; S402. The main bearing of the virtual prototype is constructed using the bearing module in Adams Machinery. The construction steps include: Select a single-row deep groove ball bearing, with the bearing housing set to ground in ADAMS. Set radial and axial constraints, bearing clearance to C0, radial and bending damping coefficients to 0.1, and axial damping coefficient to 0.

2.

6. The simulation analysis method for shape memory alloy heat engines according to claim 1, characterized in that, In step S5, the virtual prototype is statically analyzed using ANSYS Workbench to evaluate the deformation characteristics of the material under stress and to analyze the strain under maximum stress, thereby verifying its strength and stability.

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