Method for correcting simulation model of bearing tester

Abstract

The invention discloses a method for correcting a simulation model of a bearing tester, particularly relates to the field of dynamic simulation analysis of bearings, and provides a dynamic finite element simulation method of a rolling bearing based on a working condition environment of the bearing tester. The characteristic results of stress, strain distribution state, vibration response and the like of the test bearing in the operation process are extracted, and the magnitude range of the result parameters is analyzed, so that a theoretical basis and effective guidance are provided for the measurement range and precision of installation of detection equipment such as strain gauges, sensors and the like and the selection of models during the test of the high-speed heavy-load rolling bearing. According to the method provided by the invention, the simulation model is corrected through a test detection result, and a mutual comparison reference correction method of a simulation result guide test and a test test correction simulation model is formed, so that the simulation detection precision and the test level of the rolling bearing are improved. Therefore, the design level and quality of the rolling bearing are improved.

Description

Technical Field

[0001] The present invention relates to the field of bearing dynamics simulation analysis, and particularly relates to a method for correcting a simulation model of a bearing tester. Background Art

[0002] Rolling bearings are important components in the field of mechanical transmission and have been widely used in fields such as aerospace and vehicle engineering. They are one of the core components indispensable in the transmission system. Their performance plays a crucial role in the stable operation of aero-engines and helicopter main reducers. The mechanical relationships between the components of rolling bearings under operating conditions such as gears and shafts are complex, and performing dynamic finite element simulation on them has become an essential step in the bearing design stage.

[0003] At present, the vast majority of dynamic research on rolling bearings is reflected in the simulation analysis of single bearings, and there is little research on the stress, strain distribution state, and vibration response analysis of rolling bearings operating under the working conditions of a bearing tester. Most of the previous rolling bearing analyses applied the equivalent loads obtained through theoretical calculations and the boundary conditions under equivalent conversion to the inner and outer rings of a single rolling bearing. However, this often leads to the situation that the simulation analysis results cannot effectively provide a theoretical basis and practical guidance for the measurement range, accuracy, and model selection of detection devices such as strain gauges and sensors on the tester, resulting in the disconnection between simulation analysis and test detection and the inability to form a method of mutual verification and comparison. Summary of the Invention

[0004] Based on the above background art, studying the dynamic simulation analysis of rolling bearings under the working conditions of a bearing tester is of great significance for bearing test detection, design, and optimization.

[0005] To solve the above problems, the present invention designs a method for correcting a simulation model of a bearing tester to solve the problems proposed in the background art.

[0006] The present invention provides the following technical solution: A method for correcting a simulation model of a bearing tester, comprising the following steps:

[0007] S101: Calculate the geometric parameters of the rolling bearing and the tester based on the basic parameters of the rolling bearing and the tester; create a simulation model of the bearing tester in SOLIDWORKS software according to the geometric parameters, including a test bearing, a companion bearing, a shaft, a bushing, a bearing support seat, a radial loader, and an axial loader; characterized in that:

[0008] S102: Perform mesh division on the simulation model of the bearing tester based on HyperMesh mesh division software and export the mesh file in the format of a K file;

[0009] S103: Import the mesh file in LS-PrePost software, create a rigid constraint shell outside the solution domain. The external rigid constraint shell includes a bearing housing shell, a radial loader, and an axial loader shell, and merge the overlapping nodes of the flexible body and the rigid shell;

[0010] S104: Set the flexible body SECTION module and the rigid body SECTION module on the bearing tester and assign part numbers SECID in sequence. Create the linear elastic material properties of the test bearing, companion bearing, and bearing support seat, specify the rigid body material properties of the shell structure, set the material number MID, and specify the degree-of-freedom constraints according to the working condition environment. Set the PID of each part in the PART module of LS-PrePost software, and select SECID and the material property MID to make them correspond one by one;

[0011] S105: In the CONTACT module of LS-PrePost software, set the contacts for the rolling elements, cage, inner and outer rings, specify the static friction coefficient and dynamic friction coefficient, and adopt the automatic surface-to-surface contact method. For the contact between the outer ring of the bearing and the support seat, the contact between the inner ring of the bearing and the shaft, and the contact between the bushing and the shaft, adopt the surface-to-surface bonded contact method;

[0012] S106: Set the boundary conditions, rotational speed, and load for the bearing tester simulation model based on the high-speed and heavy-load working condition;

[0013] S107: Define the solution format for the bearing tester simulation model; specify the global damping coefficient, solution output format, hourglass control, time step size, and time step; set the solution memory and the number of CPU cores, submit the calculation and solution in LS-DYNA, and export the solution results;

[0014] S108: Modify the geometric parameters, mesh division parameters, and boundary conditions of the bearing tester according to the calculation results, and repeat S101 - S107 until the actual results are obtained through the solution calculation;

[0015] S109: Based on the bearing tester simulation model corrected in S108, obtain the simulation stress / strain, velocity / acceleration results, and use these as the basis to select the appropriate types, measurement ranges, accuracies of strain gauges and sensors, and the sensitive positions for installing the measurement equipment.

[0016] The present invention has the following advantages:

[0017] Based on the dynamic finite element simulation method of rolling bearings under the working conditions of a bearing tester, extract the stress, strain distribution state, vibration response and other characteristic results of the test bearing during operation, and analyze the magnitude range of the result parameters, so as to provide a theoretical basis and effective guidance for the measurement range, accuracy and model selection of detection equipment such as strain gauges and sensors when testing high-speed and heavy-duty rolling bearings. And correct the simulation model of the bearing tester through the test detection results, forming a mutual comparison and reference correction method of using simulation results to guide the test and using test measurements to correct the simulation model of the bearing tester, so as to improve the simulation detection accuracy and test level of rolling bearings. Compared with the existing technology, the method proposed by the present invention helps to form a dynamic finite element simulation detection method for bearing testers, thereby improving the design level and quality of rolling bearings. Description of the Drawings

[0018] Figure 1 It is the design flow chart of the correction method for the simulation model of the bearing tester provided by the embodiment of the present invention;

[0019] Figure 2 It is the specific implementation process of the correction method for the simulation model of the bearing tester provided by the embodiment of the present invention;

[0020] Figure 3 It is the simulation model of the bearing tester provided by the embodiment of the present invention;

[0021] Figure 4 It is the mesh division result of the simulation model of the bearing tester provided by the embodiment of the present invention;

[0022] Figure 5 It is the cross-sectional view of the simulation calculation result of the bearing tester provided by the embodiment of the present invention;

[0023] Figure 6 It is the graph of the stress change with time of a certain unit in the load-bearing area of the outer ring of the test roller bearing of the bearing tester provided by the embodiment of the present invention;

[0024] Figure 7 It is the graph of the strain change with time of a certain unit in the load-bearing area of the outer ring of the test roller bearing of the bearing tester provided by the embodiment of the present invention;

[0025] Figure 8 It is the graph of the Z-direction acceleration change with time of a certain node in the load-bearing area of the outer ring of the test roller bearing of the bearing tester provided by the embodiment of the present invention;

[0026] Figure 9 It is the model selection of the test strain gauge of the bearing tester provided by the embodiment of the present invention;

[0027] Figure 10 It is the model selection of the test sensor of the bearing tester provided by the embodiment of the present invention.

[0028] Figure 11 It is the selection of the installation positions of the test strain gauges / sensors in the bearing tester of the embodiment provided by the present invention. Specific Embodiments

[0029] The following specific embodiments illustrate the implementation manners of the present invention. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0030] As Figure 1 shown, this embodiment provides a method for correcting a simulation model of a bearing tester, including the following steps:

[0031] S101: Calculate the geometric parameters of the rolling bearing and the tester based on the basic parameters of the rolling bearing and the tester; create a simulation model of the bearing tester in SOLIDWORKS software according to the geometric parameters, including a test bearing, a companion bearing, a shaft, a bushing, a bearing support seat, a radial loader, and an axial loader, as Figures 3 - 5 shown;

[0032] Specifically: Calculate the geometric parameters of the rollers, cages, inner and outer rings of the three-point contact ball bearing and the cylindrical roller bearing respectively through the basic parameters, and create parts such as the rolling elements, cages, inner and outer rings of the test bearing and the companion bearing, the shaft, the radial loader, the axial loader, and the bearing support seat in SOLIDWORKS software through feature commands such as extrusion, revolution, and cut, and then assemble the above parts and export them in the.stp format;

[0033] S102: Perform hexahedral mesh division on the simulation model of the bearing tester based on HyperMesh mesh division software and export the mesh file in the format of a K file;

[0034] Specifically: Input the 3D model in.stp format of the bearing tester into HyperMesh for structured mesh generation. In the model module, create a new component for each part such as the bearing cage, rollers, inner and outer rings, shaft, axial loader, and radial loader, and move them into groups. Use the solid edit function to symmetrically divide each part to prepare for subsequent mesh generation. For axially symmetric components such as the axial loader, radial loader, and shaft, cut one-fourth of them. Generate 2D meshes on their axial surfaces with a size of 2 mm using the automesh function. After adjusting the settings to form regular meshes, use the solid map to rotate and stretch the 2D meshes into hexahedron meshes with a size of 2 mm. Mirror the generated one-fourth part of the component meshes through reflect to obtain a complete mesh model. The same operations are taken for the inner and outer rings of the bearing, the cage, etc., with a size of 1 mm. For the balls and cylindrical rollers, which adopt a copper coin structure, cut out one-fourth of the roller, then cut out a cube part inside, generate 2D meshes on the end faces using automesh and stretch them outwards to form 3D meshes with a given size of 1 mm. Similarly, mirror the generated meshes through reflect to obtain a complete mesh model. Finally, merge the nodes of all the generated meshes. Select a tolerance of 0.1 in the edge, merge the nodes existing inside the components due to mirror operations, and after completion, detect free edges and T-shaped edges in the edge to ensure the correctness of the mesh model and output it in the form of a K file, as Figure 4 shown.

[0035] S103: Import the mesh file in LS-PrePost, create a rigid constraint shell outside the solution domain according to the hexahedron mesh size in S102, including the bearing housing shell, radial loader, and axial loader shell, and merge the overlapping nodes of the flexible body and the rigid shell;

[0036] Specifically: Import the K file mesh model in the LS-PrePost software, select ElementGeneration in the MESH module, generate the rigid constraint shells on the surfaces of the bearing housing, radial loader, axial loader, and bearing support housing, as well as the inner surface rigid constraint shell for applying the rotational speed on the shaft by selecting the solid surfaces. Then, in Duplicate Nodes of ElementTools, first set the tolerance for duplicate nodes to 0.01 mm, then display the duplicate nodes and merge them to complete the co-node setting for the flexible body and rigid body structures such as the bearing housing and the bearing housing rigid shell, and the radial loader and the radial loader rigid shell.

[0037] S104: Set the SECTION modules of the flexible body and the rigid body SECTION module on the bearing tester and assign SECIDs to them in sequence. Create the linear elastic material properties of the test bearings (the test bearings include two types of bearings: cylindrical roller bearings and three-point contact ball bearings), companion bearings, bearing support seats, etc. Given the rigid body material properties of the housing structure, set the MID and apply the degree-of-freedom constraints according to the working condition environment. Set the PID of each part in the PART module, and select the SECID and material property MID to make them correspond one by one.

[0038] Specifically: In the Section module, create a SOLID part for each element of the flexible body structures such as the bearing seat, bearing cage, inner and outer rings of the rolling elements, and force loaders in the bearing tester. Assign SECIDs in a certain order, and the element integration formula adopts the fully integrated S / R solid full integration format; create a SHELL part for the surface rigid constraint housings of the bearing seat, radial loader, and axial loader respectively, assign the SECID, define the shear factor as 0.833, set the shell element thickness to 0.8 mm, and the element integration formula adopts the fully integrated S / R solid full integration format. In terms of the material settings of the bearing tester, it is divided into two parts: linear elastic materials and rigid materials. In terms of the linear elastic material settings, define the material density of the radial loader as 7870 kg / m 3 , the elastic modulus is 2.11×10 11 Pa, the Poisson's ratio is 0.277, set the MID to 1. The material density of the inner and outer rings and rollers of the rolling bearing is 7870 kg / m 3 , the elastic modulus is 2.09×10 11 Pa, the Poisson's ratio is 0.3, set the MID to 2. The material density of the cage is 7870 kg / m 3 , the elastic modulus is 2.09×10 11 Pa, the Poisson's ratio is 0.295, set the MID to 3. The material densities of other flexible body parts including the bearing seat, axial loader, bushing, shaft, etc. are given as 7700 kg / m 3 , the elastic modulus is 2.0×10 11 Pa, the Poisson's ratio is 0.3, set the MID to 4. In terms of the rigid material settings, the given material density is 7700 kg / m 3 , the elastic modulus is 2.0×10 11 Pa, the Poisson's ratio is 0.3, set the MID to 5. According to the working condition, constrain all the degrees of freedom of the bearing seat, and release the Y-direction degree of freedom of the radial loader and the Z-direction degree of freedom of the axial loader respectively. Based on the above settings, in the PART module, assign the corresponding PID, SECID, and MID to each part in sequence, and keep other settings as default.

[0039] S105: Perform contact settings in the CONTACT module for the rolling elements, cage, inner and outer rings. Specify the static friction coefficient and dynamic friction coefficient. The contact method is automatic surface-to-surface contact. For the contact between the outer ring of the bearing and the support seat, the contact between the inner ring of the bearing and the shaft, and the contact between the bushing and the shaft, use surface-to-surface tied contact.

[0040] Specifically: In the Contact module, use the automatic surface-to-surface contact method to set the contact between the rollers and the inner and outer rings respectively. The rollers are the slave surfaces, and the inner and outer rings are both the master surfaces. The dynamic friction coefficient is 0.15, the static friction coefficient is 0.2, and the exponential decay coefficient is 1×10 -5 , and the stiffness penalty factor for the master and slave surfaces is given as 1.5; for the contact between the balls and the inner and outer rings, the dynamic friction coefficient is 0.05, the static friction coefficient is 0.1, and the exponential decay coefficient is 1×10 -5 ; for the contact between the balls and the cage, the dynamic friction coefficient is 0.005, the static friction coefficient is 0.01, and the exponential decay coefficient is 1×10 -5 , and the stiffness penalty factor for the master and slave surfaces is given as 1.0. The rollers are in contact as slave surfaces, and the inner and outer rings and the cage are in contact as master surfaces. Use the surface-to-surface tied contact method to set the contact between the outer ring of the bearing and the bearing seat, and the contact between the inner ring and the shaft. The inner and outer rings are the slave surfaces, and the bearing seat and the shaft are the master surfaces. The dynamic friction coefficient is 0.15, the static friction coefficient is 0.2, and the exponential decay coefficient is 1×10 -5 .

[0041] S106: Set the boundary conditions, rotational speed, and load for the bearing tester model based on the conditions of high-speed and heavy-duty operation.

[0042] Specifically: Define the load curve and rotational speed curve with a radial load of 22624.6 N, an axial load of 13115.2 N, and a rotational speed of 20900 rpm according to the actual working conditions. Specify a ramp loading method during the start-up phase. In the LOAD module, select the rigid shell of the radial load loader as the load application object, with the load direction being the negative Y direction. Select the rigid shell of the axial load loader as the load application object, with the load direction being the negative Z direction. In the Boundary module, select the rigid shell element on the inner surface of the shaft as the rotational speed application object, and the entire tester rotates around the Z axis. Select the end face nodes of the cylindrical roller bearing cage to constrain its axial displacement.

[0043] S107: Define the model solution format; specify the global damping coefficient, solution output format, hourglass control, time step, and time step; set the solution memory and the number of CPU cores, submit the calculation and solution in LS-DYNA, and export the solution results;

[0044] Specifically: Set the solution accuracy, hourglass control, energy control, etc. in CONTROL, set the solution time to 0.05 s, and the time step to 1×10 -4 s; Set the global damping coefficient to 0.05 in the GLOBAL tab of DAMPING. Set the output format to LS-DYNA database format in the FORMAT of DATABASE, and the calculation results are output in the D3PLOT format, with the time interval between outputs being 1×10 -5 s; Set the calculation storage to 9999999 and the number of CPU solution cores to 16 cores in the Keyword module. Select the simulation environment as LS-DYNA Solver in the ANSYS Mechanical APDL Product Launcher solver module, correctly select the working directory and the K file import directory, and finally submit the solution.

[0045] S108: Modify the geometric parameters, mesh division parameters, and boundary conditions of the bearing tester according to the calculation results, and repeat S101 - S107 until the actual results are obtained through the solution calculation.

[0046] Specifically: After the solution is completed, import the result D3PLOT file into LS-PrePost, and output parameter results such as stress-strain, velocity-acceleration, etc. in POST. Install strain gauges, sensors and other detection devices at the obvious stress-bearing parts of the test bearing of the bearing tester with reference to the simulation results. Compare the test conclusions with the simulation results, analyze the error sources, modify the geometric parameters, refine the mesh of the test bearing, and adjust the boundary conditions, and repeat S101 - S107 until the actual results are obtained through the solution calculation. The above operation steps can analyze the influence law of load, rotational speed and cage structure on the roller yaw angle within a certain range, and play an important role in optimizing the bearing structure and reducing its vibration and noise.

[0047] S109: Based on the simulation stress / strain, velocity / acceleration results obtained from the simulation model of the bearing tester corrected in S108, select the model, measurement range, accuracy of the strain gauge and sensor, and the sensitive positions for installing the measurement equipment.

[0048] Specifically: According to the simulation stress / strain, velocity / acceleration and other parameter results obtained from the simulation model corrected in step S108, such as Figures 6 - 8As shown, the magnitude of the stress is analyzed to be 200 MPa, and the magnitude of the strain is within 5 microstrains. The type of strain gauge selected is BHI350-3AA(11)R12, with a sensitivity coefficient of 1.8 to 2.20. The type of acceleration sensor selected is CT1000G, and the transverse sensitivity ratio is less than 3%. The positions for installing the strain gauges and sensors are selected at three load-bearing areas and the top where the strain and acceleration are more sensitive during the simulation process, such as Figures 9 - 11 shown.

[0049] such as Figure 2 shown. The specific implementation steps are as follows:

[0050] S1: Calculate the geometric parameters of the rolling bearing and the tester based on the basic parameters of the test bearing and the tester;

[0051] S2: Create a simulation model of the bearing tester in SOLIDWORKS according to the geometric parameters in S1, including the test bearing, the accompanying test bearing, the shaft, the bushing, the bearing support seat, the radial loader, and the axial loader;

[0052] S3: Based on the HyperMesh meshing software, use the structured meshing method to perform hexahedral meshing on the bearing tester simulation model and export the mesh file in the format of a K file;

[0053] S4: Import the mesh file in LS-PrePost, and create rigid shell meshes for constraining the bearing seat, applying radial and axial forces, and adding the shaft rotation speed according to the hexahedral mesh size in S3;

[0054] S5: Overlap and merge the nodes of the created rigidly constrained shell of the bearing seat, the rigidly constrained shell of the radial loader, and the rigidly constrained shell of the axial loader shell with the corresponding flexible bodies respectively;

[0055] S6: Set the SECTION modules of the flexible bodies and the rigid body SECTION module on the bearing tester and assign a unique SECID;

[0056] S7: Create linear elastic material properties for structures such as the test bearing, the accompanying test bearing, and the bearing support seat, assign rigid body material properties to the shell structure, set the MID, and give the degree-of-freedom constraints according to the working conditions;

[0057] S8: Set the PID of each part in the PART module, and select the SECID and the material property MID to correspond one by one;

[0058] S9: Set up the contacts for the rolling elements, the cage, and the inner and outer rings, give the static friction coefficient and the dynamic friction coefficient, and use the automatic surface-to-surface contact method;

[0059] S10: Adopt a surface-to-surface bonded contact method for the contact between the outer ring of the bearing and the support seat, the contact between the inner ring of the bearing and the shaft, and the contact between the bushing and the shaft;

[0060] S11: Set boundary conditions, rotational speed, and load for the bearing tester model based on high-speed and heavy-load working conditions;

[0061] S12: Define model solution controls, including solution accuracy, hourglass control, and energy output, define the time step and solution time;

[0062] S13: Set the result output format;

[0063] S14: Given the global damping coefficient,

[0064] S15: Set the solution memory and the number of CPU cores;

[0065] S16: Complete the model setup and output it in the K file format;

[0066] S17: Submit the K file in LS-DYNA for solution calculation;

[0067] S18: Import the solution results into LS-PrePost to extract the results;

[0068] S19: Modify the geometric parameters, mesh generation parameters, and boundary conditions of the bearing tester according to the calculation results of S18, and repeat steps S1 to S18 until the solution calculates results that conform to the actual situation;

[0069] S20: According to the simulation stress / strain, velocity / acceleration and other parameter results obtained from the simulation model corrected in S19, as Figures 6 - 8 shown, select the model, measurement range, and accuracy of the strain gauge and sensor, as well as the sensitive positions for installing the measurement equipment, as Figures 9 - 11 shown.

[0070] Although the present invention has been described in detail above with general descriptions and specific embodiments, based on the present invention, some modifications or improvements can be made, which are obvious to those skilled in the art. Therefore, these modifications or improvements made without departing from the spirit of the present invention all fall within the scope of protection required by the present invention.

Claims

1. A method for correcting a bearing tester simulation model, comprising the following steps: S101: Calculate the geometric parameters of the rolling bearing and the tester based on the basic parameters of the rolling bearing and the tester; create a bearing tester simulation model in SOLIDWORKS software according to the geometric parameters, including a test bearing, a companion test bearing, a shaft, a bushing, a bearing support seat, a radial loader and an axial loader; characterized in that: S102: Meshing the bearing tester simulation model based on HyperMesh meshing software and exporting the mesh file in a K file format; S103: importing the mesh file into LS-PrePost software, creating an external rigid constraint shell of the solution domain, wherein the external rigid constraint shell includes a bearing seat shell, a radial loader, and an axial loader shell, and merging overlapping nodes of the flexible body and the rigid shell; S104: Set the flexible body SECTION module and the rigid body SECTION module on the bearing tester and assign part numbers SECID in sequence, create linear elastic material properties of the test bearing, companion test bearing, and bearing support seat, give the rigid body material properties of the shell structure, set the material number MID, and give the degree of freedom constraints according to the working environment, set the PID of each part in the PART module in the LS-PrePost software, and select SECID and material property MID to make one-to-one correspondence; S105: In the CONTACT module of the LS-PrePost software, the contact settings are made for the rolling elements, cages, inner and outer rings. The static friction coefficient and dynamic friction coefficient are given, and the contact mode adopts automatic surface-to-surface contact. The contact between the outer ring of the bearing and the support seat, the inner ring of the bearing and the shaft, and the sleeve and the shaft adopt the surface-to-surface binding contact mode. S106: setting boundary conditions, speed and load for the bearing tester simulation model based on high-speed and heavy-load working conditions; S107: Define the solution format of the bearing tester simulation model; set the global damping coefficient, solution output format, hourglass control, time step and time step; set the solution memory and CPU core number, submit the calculation solution in LS-DYNA and export the solution results; S108: modifying the geometric parameters, meshing parameters and boundary conditions of the bearing tester according to the calculation results, and repeating S101 to S107 until a result that meets the actual situation is obtained; S109: Based on the modified bearing tester simulation model of S108, the simulated stress / strain, velocity / acceleration results are obtained, which are used as the basis for selecting the appropriate strain gauge and sensor model, measurement range and accuracy, and sensitive location for installing the measurement equipment.

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