Evaluation and analysis method and system for support

Abstract

The invention discloses an evaluation and analysis method and system for a support, and belongs to the field of support testing. The method comprises the following steps: carrying out modal analysis on a to-be-tested bracket; carrying out a complete vehicle comprehensive endurance test to generate a load spectrum; integrating the modal analysis result and the load spectrum to carry out support fatigue damage analysis so as to evaluate whether the to-be-tested support meets the design requirements or not; and carrying out a random vibration experiment on the bracket produced according to the design requirements so as to evaluate whether the produced bracket meets the production requirements or not. According to the invention, all-around evaluation and analysis of the whole process from design to production of the bracket are realized, so that the reliability of the bracket is improved.

Description

Technical Field

[0001] The present invention belongs to the field of stent testing, and in particular, relates to a stent evaluation and analysis method and system. Background Art

[0002] The design of passenger car brackets has gradually shifted from previous empirical design to forward development with technological innovation. Through use summary analysis, bracket failure caused by statics is no longer the main form of passenger car bracket failure. Failure caused by random vibration has become the main form of bracket failure. The excitation sources of random vibration mainly come from the road, engine, gearbox wheels, wheel suspension work and abnormal shaking, which causes the bracket to resonate in a short period of time or fail due to long-term vibration fatigue.

[0003] In the practice of random vibration, the existing technology has the problem that the random vibration test causes the bracket to fail, and the bracket is still damaged after replacing the commonly used metal materials and optimizing the structure. The test parameters cannot fully fit the actual use conditions.

[0004] The development parts have not been fully evaluated and analyzed for the rationality of differences in design structure and process, installation position, load, and material selection, which will lead to problems in durability road testing, which will lead to redevelopment of the design and affect the product's launch schedule. Therefore, it is necessary to improve the existing bracket evaluation and analysis methods to provide a reference for future development work.

[0005] The present invention aims to overcome the deficiencies of the prior art and proposes a method and system for evaluating and analyzing a stent to achieve the following objectives: to achieve a comprehensive evaluation and analysis of the stent from design to production, thereby improving the reliability of the stent.

[0006] In order to achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for evaluating and analyzing a stent, the method comprising the following steps:

[0008] Step S1, obtaining the design data of the bracket to be tested and importing it into finite element analysis software for modal analysis;

[0009] Step S2, conducting a comprehensive vehicle durability test to obtain time-domain road spectrum data of brackets at different installation positions under the entire test road condition, and importing the processed data as load spectrum data into finite element analysis software to perform fatigue damage analysis on the bracket to be tested;

[0010] Step S3: when the fatigue damage value of the tested bracket meets the preset target value, it is determined that the tested bracket meets the design requirements, and the corresponding tooling is produced according to the corresponding design data, and the corresponding load is installed;

[0011] Step S4, using the load spectrum data processed in step S2 as test data, performing a random vibration test on the tooling after the load is installed;

[0012] Step S5: After the random vibration test, if the tooling is not damaged, it is determined that the tooling meets the production requirements.

[0013] Preferably, the step S1 specifically includes:

[0014] S11, obtaining design data of the stent to be tested, wherein the design data includes performance parameters of the stent material and load parameters applied to the stent;

[0015] S12, assigning the stent material performance parameters to the stent to be tested, wherein the stent material performance parameters include SN curve, yield and tensile strength, Poisson's ratio, and density;

[0016] S13, loading the load parameters into the finite element mesh of the support to be tested in the form of the center of mass and performing modal analysis.

[0017] Preferably, when performing modal analysis, the design requirements for the bracket installed on the vehicle body must meet the following conditions: the first-order mode is greater than or equal to 30 Hz.

[0018] Preferably, the step S2 specifically includes:

[0019] S21. During the comprehensive durability test of the whole vehicle, the time domain road spectrum data of the brackets at different installation positions under the whole test road condition are obtained through the road spectrum acquisition and analysis system, wherein the installation positions include the body, gearbox, engine, wheels, and wheel suspension parts of the front cabin of the whole vehicle;

[0020] S22, converting the time-domain road spectrum data into frequency-domain load spectrum data and performing filtering processing, wherein the frequency-domain load spectrum data includes RMS value, vibration frequency, and power spectrum density function value;

[0021] S23, performing signal amplification processing on the frequency domain load spectrum data;

[0022] S24, importing the amplified frequency domain load spectrum data into finite element analysis software to perform fatigue damage analysis on the tested bracket.

[0023] Preferably, in step S21, the vibration directions of the time domain road spectrum data are divided into three directions of X, Y, and Z. Correspondingly, in step S22, the frequency domain load spectrum data include RMS values, vibration frequencies, and power spectrum density function values ​​in the three directions of X, Y, and Z.

[0024] Preferably, in step S23, for the bracket installed on the vehicle body, the frequency range after amplification is selected to be in the range of 3Hz-250Hz; for the bracket installed on the engine, the frequency range after amplification is selected to be in the range of 10Hz-2000Hz; for the bracket installed on the gearbox, the frequency range after amplification is selected to be in the range of 100Hz-440Hz; for the bracket installed on the wheel, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz; for the bracket installed on the wheel suspension, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz.

[0025] Preferably, the step S3 further comprises: when the fatigue damage value of the tested bracket does not meet the preset target value, it is determined that the tested bracket does not meet the design requirements, and the following steps are performed in sequence:

[0026] S31, after reselecting the stent material, return to step S1 for reanalysis;

[0027] S32: If the design requirements are still not met after the stent material is reselected, the entire stent to be tested is redesigned and the process returns to step S1 for reanalysis.

[0028] Preferably, in step S5, if the tooling is damaged, it is determined that the tooling does not meet the production requirements. At this time, it is necessary to improve the production process and then produce the tooling again and conduct a random vibration test until the produced tooling is not damaged, wherein the production process improvement includes the improvement of the production mold.

[0029] Preferably, the test road conditions of the comprehensive vehicle durability test include a variety of enhanced bad roads, and a comprehensive road condition combining a variety of enhanced bad roads.

[0030] At the same time, the present application also proposes a bracket evaluation and analysis system, which is constructed according to any of the above-mentioned bracket evaluation and analysis methods, including: a bracket modal analysis module, a load spectrum generation module, a bracket design requirement evaluation module, and a bracket production requirement evaluation module, wherein:

[0031] The bracket modal analysis module is used to perform modal analysis on the bracket to be tested;

[0032] The load spectrum generating module is used to generate a load spectrum;

[0033] The bracket design requirement evaluation module is used to evaluate whether the bracket to be tested meets the design requirements by combining the modal analysis results and the load spectrum;

[0034] The bracket production requirement evaluation module is used to perform a random vibration experiment on the bracket produced according to the design requirements to evaluate whether the produced bracket meets the production requirements.

[0035] The technical effects of the present invention are:

[0036] 1. The present invention establishes a comprehensive evaluation and analysis of the entire process from design to production of the bracket, including modal analysis, fatigue analysis, etc., among which, the analysis under random vibration conditions is also taken into account, the analysis process is clarified, and the design compliance in the data design stage and the physical reliability in the physical verification stage can be objectively evaluated.

[0037] 2. The time-domain road spectrum data is converted into the frequency domain and amplified. It has wide applicability for similar vehicle models and can be used for data analysis in the design stage. It can also be used for reliability verification of random vibration fatigue of physical tooling and mold parts.

[0038] 3. Through the limited analysis of random vibration, a more reasonable bracket design can be obtained, avoiding repeated verification of physical objects and shortening the development cycle. Therefore, in the physical stage, it is only necessary to verify the rationality of the production or manufacturing process, which greatly reduces the development cycle and reduces development costs for enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 The present invention is a flowchart of a method for evaluating and analyzing a stent according to an embodiment of the present invention. DETAILED DESCRIPTION

[0040] The following is a further detailed description of the specific implementation of the present invention by describing the embodiments with reference to the accompanying drawings, with the purpose of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention and to facilitate its implementation. In order to make the technical solution of the present invention clearer, the present invention is explained by the following embodiments.

[0041] A bracket evaluation and analysis method, this embodiment is mainly applied to brackets installed on the body, gearbox, engine, wheel, and wheel suspension of a passenger car, such as Figure 1 As shown, the method comprises the following steps:

[0042] Step S1, obtain the design data of the bracket to be tested and import it into the finite element analysis software for modal analysis. Finite element analysis (FEA) uses mathematical approximation methods to simulate real physical systems (geometry and load conditions), and is applied to the analysis of various structural strengths. It is widely used in various fields, especially the strength analysis of passenger car brackets. Commonly used finite element software includes ANSYS, SDRC / I-DEAS, etc., which can be flexibly selected according to actual conditions during specific implementation. Mode is a representation of the characteristics of the vibration system. It is actually the simplest or most basic vibration form that constitutes the complex vibrations of various engineering structures. The natural frequency and main vibration mode of the structure can be obtained through modal analysis, which provides a basis for the dynamic design and fault diagnosis of the vibration system. At the same time, it is also the basis for other more detailed dynamic analysis.

[0043] Specifically, the step S1 includes:

[0044] S11. Obtain the design data of the bracket to be tested, wherein the design data includes the performance parameters of the bracket material, the load parameters applied to the bracket, etc. The present invention will not elaborate on the design of the bracket structure, but when designing the bracket, the selection of the bracket material is crucial. Different materials determine different bracket strengths and bring different bracket characteristics, which will affect whether the bracket meets the design requirements; at the same time, since the bracket is not used alone in the actual application environment, it is often combined with various loads. The forces applied by these loads on the bracket will also affect the strength of the bracket, especially when random vibration occurs. Resonance may occur, causing the bracket to be damaged and fail. Therefore, when performing bracket simulation analysis, the support of the bracket material performance parameters and the load parameters applied to the bracket is required to improve the accuracy of the analysis.

[0045] S12, assigning the stent material performance parameters to the stent to be tested, wherein the stent material performance parameters include SN curve, yield and tensile strength, Poisson's ratio, density, etc.

[0046] S13, loading the load parameters into the finite element mesh of the bracket to be tested in the form of the centroid and performing modal analysis. In the finite element analysis software, after the model of the bracket to be tested is constructed, the model will be divided into units to form a finite element mesh. According to the finite element mesh, the load can be accurately applied to the corresponding unit to more accurately simulate the actual situation, thereby improving the accuracy of the analysis.

[0047] In an optional embodiment of the present invention, when performing modal analysis, the design requirements for the bracket installed on the vehicle body must meet the condition that the first-order mode is greater than or equal to 30Hz. In modal analysis, the first-order mode is an important parameter that represents the basic vibration characteristics of the structure. This embodiment designs such a condition mainly to ensure that the bracket can effectively avoid its internal and external excitation frequencies during the operation of the vehicle to prevent resonance, thereby ensuring the structural strength and durability of the bracket. At the same time, this condition can improve the ride comfort of the vehicle.

[0048] Step S2, conduct a comprehensive endurance test of the whole vehicle to obtain the time domain road spectrum data of the brackets at different installation positions under the entire test road conditions, and import the processed data as load spectrum data into the finite element analysis software to perform fatigue damage analysis of the bracket to be tested. In this embodiment, the test road conditions of the comprehensive endurance test of the whole vehicle include a variety of reinforced bad roads (such as twisted roads, stone roads, cobblestone roads, gravel roads, washboard roads, long wave roads, etc.), and a comprehensive road condition combining a variety of reinforced bad roads, thereby improving the coverage of the test and ensuring the integrity and reliability of the test data.

[0049] Specifically, the step S2 includes:

[0050] S21. During the comprehensive durability test of the whole vehicle, the time-domain road spectrum data of the brackets at different installation positions under the whole test road condition is obtained through the road spectrum acquisition and analysis system, wherein the installation positions include the body, gearbox, engine, wheels, and wheel suspension parts of the front cabin of the whole vehicle. The road spectrum acquisition and analysis system is a common means used by those skilled in the art. There are mature testing instruments in the prior art, such as the Siemens road spectrum acquisition and analysis system model SCR209. In addition, in this embodiment, the vibration direction of the time-domain road spectrum data is divided into three directions: X, Y, and Z, which are used to distinguish directions and ensure data consistency in the subsequent random vibration test.

[0051] S22. Convert the time domain road spectrum data into frequency domain load spectrum data and perform filtering processing. The frequency domain load spectrum data includes RMS values, vibration frequencies, and power spectrum density function values ​​in the three directions of X, Y, and Z. Among them, the time domain signal can be converted into a frequency domain signal by using methods such as Fourier transform, Laplace transform, short-time Fourier transform, and wavelet transform. These are all common means used by those skilled in the art. The present invention will not be described in detail here. When it is implemented, it can be flexibly selected according to the actual situation. Filtering processing is mainly used to remove invalid signals in the frequency domain load spectrum data to ensure effectiveness. The reason is that most of the fatigue damage of parts comes from the large loads in the original data. There are many small loads (such as smooth roads) that contribute little to the damage but take up most of the time. This part of the data should be reduced to ensure that the test can be completed quickly and accurately. Generally, filtering can use existing technologies such as Kalman filtering.

[0052] S23, performing signal amplification processing on the frequency domain load spectrum data. Since the obtained frequency domain signal parameter value is small and cannot be directly applied to the subsequent random vibration test, signal amplification processing is required. Specifically, for brackets in different installation positions, the amplified bracket vibration frequency range should also be different, so as to ensure that the test is completed quickly and accurately.

[0053] In an optional embodiment of the present invention, for the bracket installed on the vehicle body, the frequency range after amplification is selected to be in the range of 3Hz-250Hz; for the bracket installed on the engine, the frequency range after amplification is selected to be in the range of 10Hz-2000Hz; for the bracket installed on the gearbox, the frequency range after amplification is selected to be in the range of 100Hz-440Hz; for the bracket installed on the wheel, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz; for the bracket installed on the wheel suspension, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz.

[0054] S24. Import the amplified frequency domain load spectrum data into the finite element analysis software to perform fatigue damage analysis on the bracket to be tested. The frequency domain load spectrum data processed by S21-S23 can accurately simulate the working condition of random vibration. At this time, through the finite analysis of random vibration, a more reasonable bracket design scheme can be obtained, avoiding repeated verification of physical objects and shortening the development cycle. At present, most finite element analysis software on the market supports fatigue damage analysis mode. When using it, you only need to switch to the corresponding mode based on the original bracket model and import the load spectrum. The operation is simple.

[0055] Step S2 of this embodiment performs frequency domain conversion and amplification processing on the time domain road spectrum data, which has wide applicability to similar vehicle models and can be used for data analysis in the design phase, as well as for reliability verification of random vibration fatigue of physical tooling and mold parts.

[0056] Step S3: When the fatigue damage value of the bracket to be tested meets the preset target value, the bracket to be tested is determined to meet the design requirements, and the corresponding tooling is produced according to its corresponding design data, and the corresponding load is installed. When installing the load, it is required to be installed in the same direction of the coordinates of the whole vehicle.

[0057] The fatigue damage value is jointly determined by the faults or damages occurring during the fatigue damage analysis process and the corresponding number of load cycles, the location and size of the damage, the direction and starting and ending points, the crack propagation law and other factors. In an optional embodiment of the present invention, the corresponding weights can be set for the determining factors of each fatigue damage value according to the corresponding importance, and then the fatigue damage value is obtained by weighted calculation of each determining factor, and the target value is preset based on this. In this embodiment, the preset target value can be set to 1, that is, when the fatigue damage value of the bracket to be tested is less than or equal to 1, it is determined that the bracket to be tested meets the design requirements, and when the fatigue damage value of the bracket to be tested is greater than 1, it is determined that the bracket to be tested does not meet the design requirements.

[0058] Further, when the fatigue damage value of the tested bracket does not meet the preset target value, it is determined that the tested bracket does not meet the design requirements, and the following steps are performed in sequence:

[0059] S31, after reselecting the stent material, return to step S1 for reanalysis;

[0060] S32. When the design requirements are still not met after the stent material is reselected, the entire stent to be tested is redesigned, especially the stent structure design, and the process returns to step S1 for reanalysis.

[0061] Step S4, install the support fixture with the load installed on the vibration test bench, and use the load spectrum data processed in step S2, that is, the load spectrum data after signal amplification, as test data to perform a random vibration test on the fixture with the load installed. Since the design requirements of the support have been evaluated in step S3, it is only necessary to verify the rationality of the production or manufacturing process in the physical production stage, which greatly reduces the development cycle and reduces the development cost for the enterprise.

[0062] Step S5: After the random vibration test, if the tooling is not damaged, it is determined that the tooling meets the production requirements. If the tooling is damaged, it is determined that the tooling does not meet the production requirements. At this time, it is necessary to improve the production process and then produce the tooling again and conduct a random vibration test until the tooling is not damaged. The production process improvement includes the improvement of the production mold, etc.

[0063] At the same time, the present application also proposes a bracket evaluation and analysis system, which is constructed according to any of the above-mentioned bracket evaluation and analysis methods, including: a bracket modal analysis module, a load spectrum generation module, a bracket design requirement evaluation module, and a bracket production requirement evaluation module, wherein:

[0064] The bracket modal analysis module is used to perform modal analysis on the bracket to be tested;

[0065] The load spectrum generating module is used to generate a load spectrum;

[0066] The bracket design requirement evaluation module is used to evaluate whether the bracket to be tested meets the design requirements by combining the modal analysis results and the load spectrum;

[0067] The bracket production requirement evaluation module is used to perform a random vibration experiment on the bracket produced according to the design requirements to evaluate whether the produced bracket meets the production requirements.

[0068] The present invention establishes a comprehensive evaluation and analysis of the entire process from design to production of the bracket, including modal analysis, fatigue analysis, etc., among which, the analysis under random vibration conditions is also taken into account, the analysis process is clarified, and the design compliance in the data design stage and the physical reliability in the physical verification stage can be objectively evaluated.

[0069] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for evaluating and analyzing a stent, characterized in that: The method comprises the following steps: Step S1, obtaining the design data of the bracket to be tested and importing it into finite element analysis software for modal analysis; Step S2, conducting a comprehensive vehicle durability test to obtain time-domain road spectrum data of brackets at different installation positions under the entire test road condition, and importing the processed data as load spectrum data into finite element analysis software to perform fatigue damage analysis on the bracket to be tested; Step S3: when the fatigue damage value of the tested bracket meets the preset target value, it is determined that the tested bracket meets the design requirements, and the corresponding tooling is produced according to the corresponding design data, and the corresponding load is installed; Step S4, using the load spectrum data processed in step S2 as test data, performing a random vibration test on the tooling after the load is installed; Step S5: After the random vibration test, if the tooling is not damaged, it is determined that the tooling meets the production requirements.

2. A stent evaluation and analysis method according to claim 1, characterized in that: The step S1 specifically includes: S11, obtaining design data of the stent to be tested, wherein the design data includes performance parameters of the stent material and load parameters applied to the stent; S12, assigning the stent material performance parameters to the stent to be tested, wherein the stent material performance parameters include SN curve, yield and tensile strength, Poisson's ratio, and density; S13, loading the load parameters into the finite element mesh of the support to be tested in the form of the center of mass and performing modal analysis.

3. A stent evaluation and analysis method according to claim 2, characterized in that: When performing modal analysis, the design requirements for the bracket installed on the vehicle body must meet the following conditions: the first-order mode is greater than or equal to 30 Hz.

4. The stent evaluation and analysis method according to claim 1, characterized in that: The step S2 specifically includes: S21. During the comprehensive durability test of the whole vehicle, the time domain road spectrum data of the brackets at different installation positions under the whole test road condition are obtained through the road spectrum acquisition and analysis system, wherein the installation positions include the body, gearbox, engine, wheels, and wheel suspension parts of the front cabin of the whole vehicle; S22, converting the time-domain road spectrum data into frequency-domain load spectrum data and performing filtering processing, wherein the frequency-domain load spectrum data includes RMS value, vibration frequency, and power spectrum density function value; S23, performing signal amplification processing on the frequency domain load spectrum data; S24, importing the amplified frequency domain load spectrum data into finite element analysis software to perform fatigue damage analysis on the tested bracket.

5. A stent evaluation and analysis method according to claim 4, characterized in that: In step S21, the vibration directions of the time domain road spectrum data are divided into three directions: X, Y, and Z. Correspondingly, in step S22, the frequency domain load spectrum data includes RMS values, vibration frequencies, and power spectrum density function values ​​in the three directions of X, Y, and Z.

6. A stent evaluation and analysis method according to claim 4, characterized in that: In the step S23, for the bracket installed on the vehicle body, the frequency range after amplification is selected to be in the range of 3Hz-250Hz; for the bracket installed on the engine, the frequency range after amplification is selected to be in the range of 10Hz-2000Hz; for the bracket installed on the gearbox, the frequency range after amplification is selected to be in the range of 100Hz-440Hz; for the bracket installed on the wheel, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz; for the bracket installed on the wheel suspension, the frequency range after amplification is selected to be in the range of 20Hz-2000Hz.

7. A stent evaluation and analysis method according to any one of claims 1 to 6, characterized in that: The step S3 further includes: when the fatigue damage value of the tested bracket does not meet the preset target value, it is determined that the tested bracket does not meet the design requirements, and the following steps are performed in sequence: S31, after reselecting the stent material, return to step S1 for reanalysis; S32: If the design requirements are still not met after the stent material is reselected, the entire stent to be tested is redesigned and the process returns to step S1 for reanalysis.

8. A stent evaluation and analysis method according to any one of claims 1 to 6, characterized in that: In step S5, if the tooling is damaged, it is determined that the tooling does not meet the production requirements. At this time, it is necessary to improve the production process and then produce the tooling again and conduct a random vibration test until the produced tooling is not damaged, wherein the production process improvement includes the improvement of the production mold.

9. A stent evaluation and analysis method according to any one of claim 1, characterized in that: The test road conditions of the comprehensive vehicle durability test include multiple enhanced bad roads and comprehensive road conditions combining multiple enhanced bad roads.

10. A stent evaluation and analysis system, characterized in that: The system is constructed according to a bracket evaluation and analysis method according to any one of claims 1 to 9, including: a bracket modal analysis module, a load spectrum generation module, a bracket design requirement evaluation module, and a bracket production requirement evaluation module, wherein: The bracket modal analysis module is used to perform modal analysis on the bracket to be tested; The load spectrum generating module is used to generate a load spectrum; The bracket design requirement evaluation module is used to evaluate whether the bracket to be tested meets the design requirements by combining the modal analysis results and the load spectrum; The bracket production requirement evaluation module is used to perform a random vibration experiment on the bracket produced according to the design requirements to evaluate whether the produced bracket meets the production requirements.

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