Vibration detection optimization method and system of support structure

Abstract

The invention discloses a vibration detection optimization method and system for a support structure, and belongs to the technical field of support simulation. The method comprises the following steps: performing modal simulation on a complete machine model of a fuel cell system to obtain a modal frequency and a bracket vibration mode, and performing random vibration detection and sweep frequency vibration detection on the complete machine model based on the modal frequency and the bracket vibration mode to obtain a random vibration stress detection result and a sweep frequency vibration stress detection result of the bracket; the support which does not meet the requirement is optimized by obtaining the random vibration stress detection result and the sweep frequency vibration stress detection result of the support. According to the invention, random vibration detection and sweep frequency vibration detection are carried out on a modal simulation result, so that the detection efficiency and accuracy of random vibration detection and sweep frequency vibration detection are improved; through combination of random vibration detection and sweep frequency vibration detection, the support is detected and optimized, the resonance point of the support can be identified, the risk of resonance fracture of the support is reduced, and the stability of the support is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bracket simulation, and in particular relates to a vibration detection optimization method and system for a bracket structure. Background Art

[0002] The fuel cell system is usually based on the arrangement of each bracket on the system, connecting the various subsystems in the fuel cell system so that each subsystem can meet the operation of the fuel cell system stack. Therefore, the reliability of the bracket determines the operating reliability of each fuel cell subsystem, thereby affecting the performance of the entire fuel cell system.

[0003] At present, the reliability of the bracket of the fuel cell system is usually verified through modal simulation and random vibration test. However, random vibration simulation alone cannot identify all the resonance points of the bracket, and the bracket will resonate during actual vibration, thus affecting the bracket, and in severe cases, causing the bracket to break. Therefore, a vibration detection optimization method and system for the bracket structure is urgently needed to solve the defects of the existing technology. Summary of the invention

[0004] The present invention aims to provide a vibration detection optimization method and system for a bracket structure to solve the above-mentioned technical problems, perform random vibration calculation and swept frequency vibration calculation based on the results of modal simulation calculation, achieve structural optimization of the bracket, and improve the stability of the bracket.

[0005] In order to solve the above technical problems, an embodiment of the present invention provides a vibration detection optimization method for a bracket structure, which is applicable to a fuel cell system including a bracket, comprising:

[0006] Obtaining a whole machine model of the fuel cell system, and performing modal simulation on the whole machine model to obtain modal frequencies and bracket vibration shapes;

[0007] Performing random vibration detection and swept-frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket to obtain random vibration stress detection results and swept-frequency vibration stress detection results of the bracket;

[0008] The brackets to be optimized that do not meet the preset requirements are screened according to the random vibration stress detection results and the swept frequency vibration stress detection results, and the brackets to be optimized are optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

[0009] It can be understood that, compared with the prior art, the present invention obtains the modal frequency and the vibration mode of the bracket by performing modal simulation on the whole machine model of the fuel cell system, and performs random vibration detection and swept frequency vibration detection on the whole machine model based on the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket; by obtaining the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket, the bracket that does not meet the requirements is optimized. The present invention improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation; by combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0010] As a preferred solution, performing random vibration detection and swept frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket specifically includes:

[0011] According to a preset random vibration detection method, random vibration detection is performed on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the stress value and fatigue life of the bracket are calculated, and a random vibration stress detection result of the bracket is obtained;

[0012] According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

[0013] This preferred solution improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation. By combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, thereby reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0014] As a preferred solution, the random vibration detection method is used to perform random vibration detection on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the stress value and fatigue life of the bracket are calculated, and the random vibration stress detection result of the bracket is obtained, which specifically includes:

[0015] Obtaining a material fatigue life curve corresponding to the whole machine model;

[0016] According to the material fatigue life curve, the modal frequency and the vibration mode of the bracket, a random vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the whole machine strength and life of the whole machine model;

[0017] The stress value and fatigue life of the bracket are calculated according to the overall strength and life of the overall model, and the random vibration stress detection result of the bracket is obtained.

[0018] This preferred solution can improve the efficiency and accuracy of random vibration detection by performing random vibration detection on the results of modal simulation. The random vibration detection can accurately obtain the stress value and fatigue life of the bracket, providing a data basis for subsequent optimization of the bracket and improving the stability of the bracket.

[0019] As a preferred solution, the preset sweep frequency vibration detection method is used to perform sweep frequency vibration detection on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained, which specifically includes:

[0020] Determine a sweep frequency range according to the modal frequency, and determine a sweep frequency interval according to the sweep frequency range;

[0021] According to the modal frequency and the vibration shape of the bracket, combined with the sweep frequency range and the sweep frequency interval, a sweep frequency vibration test is performed on the whole machine model through a preset finite element simulation tool to obtain the measured sweep frequency and stress curve of the bracket;

[0022] According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

[0023] As a preferred solution, according to the measured sweep frequency and stress curve, the whole machine model is subjected to sweep frequency vibration by the finite element simulation tool, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained, which specifically includes:

[0024] Identify a peak frequency point according to the measured sweep frequency and the stress curve;

[0025] Update the sweep frequency range and the sweep frequency interval according to the peak frequency point;

[0026] According to the updated sweep frequency range and sweep frequency interval, the whole machine model is subjected to a sweep frequency vibration test through the finite element simulation tool, and a sweep frequency vibration stress cloud map of the bracket is constructed to obtain a sweep frequency vibration stress test result of the bracket.

[0027] This preferred solution can improve the efficiency and accuracy of swept-frequency vibration detection by performing multiple swept-frequency vibration detection on the results of modal simulation. The swept-frequency vibration detection can fully identify the resonance points of the bracket, making up for the risk that random vibration detection cannot identify all resonance points, reducing the risk of bracket resonance fracture, and improving the stability of the bracket.

[0028] As a preferred solution, the step of screening the bracket to be optimized that does not meet the preset requirements according to the random vibration stress detection results and the swept frequency vibration stress detection results, and optimizing the bracket to be optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results, specifically includes:

[0029] Obtain the material yield strength of the bracket;

[0030] Comparing the magnitudes of the bracket stress and the material yield strength in the random vibration stress detection result and the swept frequency vibration stress detection result, and screening out the brackets to be optimized that do not meet the preset requirements;

[0031] The bracket to be optimized is optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result.

[0032] As a preferred solution, the optimization of the bracket to be optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result specifically includes:

[0033] Determining an optimization region of the bracket to be optimized according to the random vibration stress detection result and the bracket stress result in the swept frequency vibration stress detection result;

[0034] The frequency result of the bracket is obtained according to the swept frequency vibration stress detection result, and the natural frequency of the bracket is optimized according to the frequency result of the bracket.

[0035] This preferred solution optimizes the bracket through the results of random vibration testing and swept frequency vibration testing, optimizes specific areas of the bracket with the results of random vibration testing, and optimizes the stiffness of the bracket as a whole with the results of swept frequency vibration testing, thereby improving the stability of the bracket.

[0036] Accordingly, an embodiment of the present invention provides a vibration detection and optimization system for a support structure, comprising: a modal simulation module, a vibration detection module and a support optimization module;

[0037] The modal simulation module is used to obtain a whole machine model of the fuel cell system, and perform modal simulation on the whole machine model to obtain modal frequency and bracket vibration shape;

[0038] The vibration detection module is used to perform random vibration detection and swept frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket, and obtain the random vibration stress detection result and swept frequency vibration stress detection result of the bracket;

[0039] The bracket optimization module is used to screen the brackets to be optimized that do not meet the preset requirements according to the random vibration stress detection results and the swept frequency vibration stress detection results, and optimize the brackets to be optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

[0040] As a preferred solution, the vibration detection module includes: a vibration detection unit;

[0041] The vibration detection unit is used to perform random vibration detection on the whole machine model according to a preset random vibration detection method, in combination with the modal frequency and the vibration mode of the bracket, calculate the stress value and fatigue life of the bracket, and obtain the random vibration stress detection result of the bracket;

[0042] According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

[0043] As a preferred solution, the vibration detection unit includes: a sweep frequency vibration detection subunit;

[0044] The sweep frequency vibration detection subunit is used to determine the sweep frequency range according to the modal frequency, and determine the sweep frequency interval according to the sweep frequency range;

[0045] According to the modal frequency and the vibration shape of the bracket, a frequency sweep vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the measured frequency sweep frequency and stress curve of the bracket;

[0046] According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

[0047] It can be understood that, compared with the prior art, this system obtains the modal frequency and the vibration mode of the bracket by performing modal simulation on the whole machine model of the fuel cell system, and performs random vibration detection and swept frequency vibration detection on the whole machine model based on the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection results and the swept frequency vibration stress detection results of the bracket; by obtaining the random vibration stress detection results and the swept frequency vibration stress detection results of the bracket, the bracket that does not meet the requirements is optimized. This system improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation; by combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, reducing the risk of resonance fracture of the bracket and improving the stability of the bracket. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 : A flowchart of the steps of a vibration detection optimization method for a support structure provided by an embodiment of the present invention;

[0049] Figure 2 : A curve relationship diagram of a stent frequency and stress provided by an embodiment of the present invention;

[0050] Figure 3 : A schematic flow chart of another vibration detection optimization method for a support structure provided by an embodiment of the present invention;

[0051] Figure 4 : A structural diagram of a vibration detection optimization system for a support structure provided by an embodiment of the present invention;

[0052] Among them, 201: modal simulation module; 202: vibration detection module; 203: bracket optimization module. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] The integration of fuel cell systems relies on the connection of various subsystems through brackets to ensure that they can meet the operating requirements of the fuel cell stack. The reliability of the bracket is crucial to maintaining the stable operation of each subsystem, which in turn has a profound impact on the performance of the entire fuel cell system.

[0055] In order to verify the reliability and stability of the bracket, the existing technology usually adopts a method combining simulation calculation and vibration test. First, the strength problem of the bracket is identified through the simulation calculation process, such as modal analysis and random vibration calculation. Based on the simulation results, the bracket is further optimized.

[0056] However, random vibration simulation may not be able to identify all the resonance points, but the bracket will resonate during actual vibration, and the resonance has a great impact on the bracket, and in severe cases, the bracket will break. Specifically, in random vibration simulation, the smoothing effect of the power density spectrum will cover up some sharp resonance peaks, especially the resonance peaks that are not caused by the main mode, such as the resonance caused by the mode of the bracket itself; secondly, the intensity of the excitation spectrum of random vibration in certain frequency ranges is not enough to excite certain brackets to resonate; in addition, the analysis of random vibration is based on statistical averages, rather than peaks at specific frequencies, and tends to be averages over a long period of time, rather than instantaneous extreme cases, and the resonance fracture of the bracket is often an instantaneous extreme case. Therefore, simply analyzing the vibration of the bracket by modal simulation and random vibration simulation often leads to low stability of the bracket, and resonance occurs in actual use and causes fracture. Therefore, an embodiment of the present invention provides a vibration detection optimization method and device for a bracket structure, which performs random vibration calculations and swept frequency vibration calculations based on the results of modal simulation calculations, realizes structural optimization of the bracket, and improves the stability of the bracket.

[0057] Embodiment 1

[0058] Please refer to Figure 1 , which is a step flow chart of a vibration detection optimization method for a support structure provided by an embodiment of the present invention, including steps S101 to S103.

[0059] Step S101: obtaining a whole machine model of a fuel cell system, and performing modal simulation on the whole machine model to obtain modal frequencies and bracket vibration shapes.

[0060] In an optional embodiment, an overall model of the fuel cell system is obtained, wherein the overall model of the fuel cell system can be drawn by three-dimensional drawing software, and the overall model includes each component of the fuel cell system.

[0061] In an optional embodiment, the whole machine model of the fuel cell system is input into finite element simulation software, and modal simulation is performed on the whole machine model to obtain the modal frequency and the vibration shape of the bracket.

[0062] Specifically, in the finite element simulation software ANSYS, a Modal module (modal analysis module) is added, and the whole machine model of the fuel cell system is imported into the finite element simulation software ANSYS, and the whole machine model is meshed in the mesh module (grid module) of the finite element simulation software ANSYS, using a four-sided mesh to ensure that the bracket in the whole machine model has a three-layer network; then, the fixed constraints of the finite element simulation software ANSYS are set according to the actual installation position of the bracket, and the analysis frequency range is set to 0 to 200 Hz; then, the whole machine mode is calculated by the finite element simulation software ANSYS, all bracket vibration shapes between 0 and 200 Hz are identified, and the modal frequency is recorded.

[0063] The modal frequencies recorded in this embodiment are 10 Hz, 20 Hz, 40 Hz and 80 Hz.

[0064] Step S102: performing random vibration detection and swept-frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket, and obtaining random vibration stress detection results and swept-frequency vibration stress detection results of the bracket.

[0065] In this embodiment, the random vibration detection and the swept frequency vibration detection are performed on the whole machine model according to the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket, specifically including:

[0066] According to a preset random vibration detection method, random vibration detection is performed on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the stress value and fatigue life of the bracket are calculated, and a random vibration stress detection result of the bracket is obtained;

[0067] According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

[0068] This embodiment improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation. By combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, thereby reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0069] In this embodiment, the random vibration detection method is used to perform random vibration detection on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the stress value and fatigue life of the bracket are calculated, and the random vibration stress detection result of the bracket is obtained, which specifically includes:

[0070] Obtaining a material fatigue life curve corresponding to the whole machine model;

[0071] According to the material fatigue life curve, the modal frequency and the vibration mode of the bracket, a random vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the whole machine strength and life of the whole machine model;

[0072] The stress value and fatigue life of the bracket are calculated according to the overall strength and life of the overall model, and the random vibration stress detection result of the bracket is obtained.

[0073] In an optional embodiment, a random vibration module (random vibration analysis module) is added to the finite element simulation software ANSYS, the bracket vibration mode and modal frequency are imported into the random vibration module, the material fatigue life curve is obtained, and the material fatigue life curve is assigned in the random vibration module. At the same time, the load is applied according to the power spectrum density of the actual test, and the overall strength and life of the whole machine model are calculated, thereby obtaining the stress value and fatigue life of the bracket.

[0074] This embodiment can improve the efficiency and accuracy of random vibration detection by performing random vibration detection on the results of modal simulation. The random vibration detection can accurately obtain the stress value and fatigue life of the bracket, providing a data basis for subsequent optimization of the bracket and improving the stability of the bracket.

[0075] In this embodiment, the preset sweep frequency vibration detection method is used to perform sweep frequency vibration detection on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, identify the resonance point of the bracket, and obtain the sweep frequency vibration stress detection result of the bracket, which specifically includes:

[0076] Determine a sweep frequency range according to the modal frequency, and determine a sweep frequency interval according to the sweep frequency range;

[0077] According to the modal frequency and the vibration shape of the bracket, combined with the sweep frequency range and the sweep frequency interval, a sweep frequency vibration test is performed on the whole machine model through a preset finite element simulation tool to obtain the measured sweep frequency and stress curve of the bracket;

[0078] According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

[0079] In this embodiment, according to the measured sweep frequency and stress curve, the whole machine model is subjected to sweep frequency vibration by the finite element simulation tool, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained, which specifically includes:

[0080] Identify a peak frequency point according to the measured sweep frequency and the stress curve;

[0081] Update the sweep frequency range and the sweep frequency interval according to the peak frequency point;

[0082] According to the updated sweep frequency range and sweep frequency interval, the whole machine model is subjected to a sweep frequency vibration test through the finite element simulation tool, and a sweep frequency vibration stress cloud map of the bracket is constructed to obtain a sweep frequency vibration stress test result of the bracket.

[0083] In an optional embodiment, a harmonic response module (harmonic response analysis module, used for performing frequency sweep vibration detection) is added to the finite element simulation software ANSYS, and the vibration shape and modal frequency of the bracket are imported into the harmonic response module.

[0084] According to the range of modal frequencies, the sweep frequency range is determined. The modal frequencies recorded in this embodiment are 10Hz, 20Hz, 40Hz and 80Hz, so the sweep frequency range is set to 0 to 80Hz; then the sweep frequency interval is set, and this embodiment sets 2Hz as an interval for the first time, so a total of 40 interval points are set from 0 to 80Hz; at the same time, based on the bracket vibration mode, the local vibration mode of the bracket is identified, and the frequency corresponding to the local vibration mode is recorded as a reference point.

[0085] The harmonic response module of the finite element simulation software ANSYS is used to perform sweep vibration detection, extract the measured sweep frequency and stress curve of the bracket, and then identify the peak frequency point f1 based on the measured sweep frequency and stress curve. The peak frequency point f1 is set as the middle point, and the interval points are set to 10Hz before and after, with a total of 20 points. The sweep frequency range is f1±10Hz, thereby updating the sweep frequency range and sweep frequency interval.

[0086] According to the updated sweep frequency range and sweep frequency interval, the sweep frequency vibration detection is performed again through the harmonic response module of the finite element simulation software ANSYS, the relationship between the stress and frequency of the bracket is calculated, the stress cloud map of the bracket at the peak frequency is extracted, and the sweep frequency vibration stress cloud map of the bracket is constructed.

[0087] This embodiment can improve the efficiency and accuracy of swept frequency vibration detection by performing multiple swept frequency vibration detection on the results of modal simulation. The swept frequency vibration detection can fully identify the resonance points of the bracket, which makes up for the risk that random vibration detection cannot identify all resonance points, reduces the risk of bracket resonance fracture, and improves the stability of the bracket.

[0088] Step S103: screening the brackets to be optimized that do not meet the preset requirements according to the random vibration stress detection results and the swept frequency vibration stress detection results, and optimizing the brackets to be optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

[0089] In this embodiment, the step of selecting the bracket to be optimized that does not meet the preset requirements according to the random vibration stress detection result and the swept frequency vibration stress detection result, and optimizing the bracket to be optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result, specifically includes:

[0090] Obtain the material yield strength of the bracket;

[0091] Comparing the magnitudes of the bracket stress and the material yield strength in the random vibration stress detection result and the swept frequency vibration stress detection result, and screening out the brackets to be optimized that do not meet the preset requirements;

[0092] The bracket to be optimized is optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result.

[0093] In an optional embodiment, the preset requirements described in this embodiment specifically include: in the modal simulation, there is no local vibration mode of the bracket in the whole machine model (that is, the modal vibration mode cloud diagram of the bracket cannot have a local maximum value); in the random vibration stress detection results and the swept frequency vibration stress detection results, the bracket stress value is less than 0.6 times the yield strength of the material; the natural frequency of the bracket itself should be greater than 100 Hz. When it cannot be greater than 100 Hz, the natural frequency of the bracket itself should meet the requirement of being greater than 2 times the natural frequency of the fuel cell system.

[0094] In an alternative embodiment, please refer to Figure 2 , is a curve relationship diagram of a bracket frequency and stress provided by an embodiment of the present invention, such as Figure 2 As shown, the horizontal axis is frequency (unit: Hz), and the vertical axis is the frequency of the amplitude (i.e. stress, unit: MPa) at the stress peak, indicating that the bracket is prone to resonance when subjected to this frequency. If the stress value at this time is greater than the material yield strength of the bracket, the bracket is at risk of fracture due to resonance.

[0095] In an optional embodiment, by analyzing the swept frequency vibration stress cloud map, it is analyzed whether there is a stress singularity point. After eliminating the stress singularity point, the maximum stress point is extracted, and the maximum stress point is compared with the material yield strength. If the stress value of the maximum stress point is greater than the material yield strength, it means that the place is susceptible to fracture due to the resonant frequency.

[0096] In an optional embodiment, by performing random vibration testing on the bracket, the random vibration stress of the bracket is obtained to be 25Mpa. At this time, the material yield strength of the bracket is 150Mpa. Then, the bracket meets the strength requirement only through random vibration testing; the bracket is further subjected to swept frequency vibration testing, and the swept frequency vibration stress is obtained to be 237Mpa. Since the material yield strength of the bracket is 150Mpa, which exceeds the material yield strength of the bracket, the bracket is at risk of resonance fracture.

[0097] In this embodiment, the optimizing the bracket to be optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result specifically includes:

[0098] Determining an optimization region of the bracket to be optimized according to the random vibration stress detection result and the bracket stress result in the swept frequency vibration stress detection result;

[0099] The frequency result of the bracket is obtained according to the swept frequency vibration stress detection result, and the natural frequency of the bracket is optimized according to the frequency result of the bracket.

[0100] In an optional embodiment, the support structure is optimized according to the load mode, stress magnitude and location in the random vibration stress detection results and the swept frequency vibration stress detection results. When it is determined from the random vibration stress detection results and the swept frequency vibration stress detection results that the support has a large stress in the Y-axis direction, the Y direction is strengthened at the stress concentration location.

[0101] In an optional embodiment, the natural frequency of the bracket itself is increased according to the random vibration stress detection results and the swept frequency vibration stress detection results. When the frequency of the bracket under the peak stress in the swept frequency vibration stress detection results is 24 Hz, the natural frequency of the bracket itself should be greater than 48 Hz after optimization.

[0102] This embodiment optimizes the bracket through the results of random vibration detection and swept frequency vibration detection. The results of random vibration detection are used to optimize the specific area of ​​the bracket, and the results of swept frequency vibration detection are used to optimize the stiffness of the bracket as a whole, thereby improving the stability of the bracket.

[0103] In an alternative embodiment, please refer to Figure 3, which is a flow chart of another vibration detection optimization method for a bracket structure provided in an embodiment of the present invention. First, a finite element model of a fuel cell system is established, and then a modal simulation calculation is performed. According to the modal simulation calculation results, random vibration calculation and swept frequency vibration calculation are performed respectively, and the vibration intensity of the bracket is analyzed to determine whether it meets the design requirements. If not, the structure is re-optimized. When the swept frequency vibration calculation does not meet the design requirements, the single bracket that does not meet the design requirements is re-modally simulated, and the modal result is compared with the swept frequency to determine whether it is greater than 1.41 times the swept frequency peak frequency. If so, the vibration detection optimization of the bracket is completed.

[0104] This embodiment performs modal simulation on the whole machine model of the fuel cell system to obtain the modal frequency and the vibration mode of the bracket, and performs random vibration detection and swept frequency vibration detection on the whole machine model based on the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket; by obtaining the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket, the bracket that does not meet the requirements is optimized. This embodiment improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation; by combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0105] Embodiment 2

[0106] Please refer to Figure 4 , which is a structural schematic diagram of a vibration detection and optimization system for a support structure provided in an embodiment of the present invention, comprising: a modal simulation module 201, a vibration detection module 202 and a support optimization module 203.

[0107] The modal simulation module 201 is used to obtain a whole machine model of the fuel cell system, and perform modal simulation on the whole machine model to obtain modal frequencies and bracket vibration shapes.

[0108] The vibration detection module 202 is used to perform random vibration detection and swept frequency vibration detection on the whole machine model according to the modal frequency and the bracket vibration mode, and obtain random vibration stress detection results and swept frequency vibration stress detection results of the bracket.

[0109] In this embodiment, the vibration detection module 202 includes: a vibration detection unit;

[0110] The vibration detection unit is used to perform random vibration detection on the whole machine model according to a preset random vibration detection method, in combination with the modal frequency and the vibration mode of the bracket, calculate the stress value and fatigue life of the bracket, and obtain the random vibration stress detection result of the bracket;

[0111] According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

[0112] In this embodiment, the vibration detection unit includes: a random vibration detection subunit;

[0113] The random vibration detection subunit is used to obtain the material fatigue life curve corresponding to the whole machine model;

[0114] According to the material fatigue life curve, the modal frequency and the vibration mode of the bracket, a random vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the whole machine strength and life of the whole machine model;

[0115] The stress value and fatigue life of the bracket are calculated according to the overall strength and life of the overall model, and the random vibration stress detection result of the bracket is obtained.

[0116] In this embodiment, the vibration detection unit includes: a frequency sweep vibration detection subunit;

[0117] The sweep frequency vibration detection subunit is used to determine the sweep frequency range according to the modal frequency, and determine the sweep frequency interval according to the sweep frequency range;

[0118] According to the modal frequency and the vibration shape of the bracket, a frequency sweep vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the measured frequency sweep frequency and stress curve of the bracket;

[0119] According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

[0120] In this embodiment, the frequency sweeping vibration detection subunit includes: a frequency sweeping vibration detection component;

[0121] The frequency sweep vibration detection component is used to identify the peak frequency point according to the measured frequency sweep frequency and the stress curve;

[0122] Update the sweep frequency range and the sweep frequency interval according to the peak frequency point;

[0123] According to the updated sweep frequency range and sweep frequency interval, the whole machine model is subjected to a sweep frequency vibration test through the finite element simulation tool, and a sweep frequency vibration stress cloud map of the bracket is constructed to obtain a sweep frequency vibration stress test result of the bracket.

[0124] The bracket optimization module 203 is used to screen the brackets to be optimized that do not meet the preset requirements according to the random vibration stress detection results and the swept frequency vibration stress detection results, and optimize the brackets to be optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

[0125] In this embodiment, the support optimization module 203 includes: a support optimization unit;

[0126] The support optimization unit is used to obtain the material yield strength of the support;

[0127] Comparing the magnitudes of the bracket stress and the material yield strength in the random vibration stress detection result and the swept frequency vibration stress detection result, and screening out the brackets to be optimized that do not meet the preset requirements;

[0128] The bracket to be optimized is optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result.

[0129] In this embodiment, the stent optimization unit includes: a stent optimization subunit;

[0130] The bracket optimization subunit is used to determine the optimization area of ​​the bracket to be optimized according to the bracket stress results in the random vibration stress detection results and the swept frequency vibration stress detection results;

[0131] The frequency result of the bracket is obtained according to the swept frequency vibration stress detection result, and the natural frequency of the bracket is optimized according to the frequency result of the bracket.

[0132] This embodiment performs modal simulation on the whole machine model of the fuel cell system to obtain the modal frequency and the vibration mode of the bracket, and performs random vibration detection and swept frequency vibration detection on the whole machine model based on the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket; by obtaining the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket, the bracket that does not meet the requirements is optimized. This embodiment improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation; by combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0133] In summary, the embodiment of the present invention performs modal simulation on the whole machine model of the fuel cell system to obtain the modal frequency and the vibration mode of the bracket, and performs random vibration detection and swept frequency vibration detection on the whole machine model based on the modal frequency and the vibration mode of the bracket to obtain the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket; by obtaining the random vibration stress detection result and the swept frequency vibration stress detection result of the bracket, the bracket that does not meet the requirements is optimized. The embodiment of the present invention improves the detection efficiency and accuracy of random vibration detection and swept frequency vibration detection by performing random vibration detection and swept frequency vibration detection on the results of modal simulation; by combining random vibration detection and swept frequency vibration detection, the bracket is detected and optimized, and the resonance point of the bracket can be identified, thereby reducing the risk of resonance fracture of the bracket and improving the stability of the bracket.

[0134] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A vibration detection optimization method for a support structure, characterized in that: Applicable to fuel cell systems containing brackets, including: Obtaining a whole machine model of the fuel cell system, and performing modal simulation on the whole machine model to obtain modal frequencies and bracket vibration shapes; Performing random vibration detection and swept-frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket to obtain random vibration stress detection results and swept-frequency vibration stress detection results of the bracket; The brackets to be optimized that do not meet the preset requirements are screened according to the random vibration stress detection results and the swept frequency vibration stress detection results, and the brackets to be optimized are optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

2. A vibration detection optimization method for a support structure as claimed in claim 1, characterized in that: The step of performing random vibration detection and frequency sweep vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket to obtain random vibration stress detection results and frequency sweep vibration stress detection results of the bracket specifically includes: According to a preset random vibration detection method, random vibration detection is performed on the whole machine model in combination with the modal frequency and the vibration mode of the bracket, the stress value and fatigue life of the bracket are calculated, and a random vibration stress detection result of the bracket is obtained; According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

3. A vibration detection optimization method for a support structure as claimed in claim 2, characterized in that: The method of performing random vibration detection on the whole machine model according to the preset random vibration detection method in combination with the modal frequency and the vibration mode of the bracket, calculating the stress value and fatigue life of the bracket, and obtaining the random vibration stress detection result of the bracket specifically includes: Obtaining a material fatigue life curve corresponding to the whole machine model; According to the material fatigue life curve, the modal frequency and the vibration mode of the bracket, a random vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain the whole machine strength and life of the whole machine model; The stress value and fatigue life of the bracket are calculated according to the overall strength and life of the overall model, and the random vibration stress detection result of the bracket is obtained.

4. A vibration detection optimization method for a support structure as claimed in claim 2, characterized in that: The method of performing a frequency sweep vibration test on the whole machine model according to the preset frequency sweep vibration test method in combination with the modal frequency and the vibration mode of the bracket, identifying the resonance point of the bracket, and obtaining the frequency sweep vibration stress test result of the bracket specifically includes: Determine a sweep frequency range according to the modal frequency, and determine a sweep frequency interval according to the sweep frequency range; According to the modal frequency and the vibration shape of the bracket, combined with the sweep frequency range and the sweep frequency interval, a sweep frequency vibration test is performed on the whole machine model through a preset finite element simulation tool to obtain the measured sweep frequency and stress curve of the bracket; According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

5. A vibration detection optimization method for a support structure as claimed in claim 4, characterized in that: The method of performing frequency sweep vibration on the whole machine model according to the measured frequency sweep frequency and stress curve by using the finite element simulation tool, identifying the resonance point of the bracket, and obtaining the frequency sweep vibration stress detection result of the bracket specifically includes: Identify a peak frequency point according to the measured sweep frequency and the stress curve; Update the sweep frequency range and the sweep frequency interval according to the peak frequency point; According to the updated sweep frequency range and sweep frequency interval, the whole machine model is subjected to a sweep frequency vibration test through the finite element simulation tool, and a sweep frequency vibration stress cloud map of the bracket is constructed to obtain a sweep frequency vibration stress test result of the bracket.

6. A vibration detection optimization method for a support structure as claimed in claim 1, characterized in that: The step of selecting the bracket to be optimized that does not meet the preset requirements according to the random vibration stress detection result and the swept frequency vibration stress detection result, and optimizing the bracket to be optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result, specifically includes: Obtain the material yield strength of the bracket; Comparing the magnitudes of the bracket stress and the material yield strength in the random vibration stress detection result and the swept frequency vibration stress detection result, and screening out the brackets to be optimized that do not meet the preset requirements; The bracket to be optimized is optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result.

7. A vibration detection optimization method for a support structure as claimed in claim 6, characterized in that: The optimizing the bracket to be optimized according to the random vibration stress detection result and the swept frequency vibration stress detection result specifically includes: Determining an optimization region of the bracket to be optimized according to the random vibration stress detection result and the bracket stress result in the swept frequency vibration stress detection result; The frequency result of the bracket is obtained according to the swept frequency vibration stress detection result, and the natural frequency of the bracket is optimized according to the frequency result of the bracket.

8. A vibration detection optimization system for a support structure, characterized in that: include: Modal simulation module, vibration detection module and bracket optimization module; The modal simulation module is used to obtain a whole machine model of the fuel cell system, and perform modal simulation on the whole machine model to obtain modal frequency and bracket vibration shape; The vibration detection module is used to perform random vibration detection and swept frequency vibration detection on the whole machine model according to the modal frequency and the vibration mode of the bracket, and obtain the random vibration stress detection result and swept frequency vibration stress detection result of the bracket; The bracket optimization module is used to screen the brackets to be optimized that do not meet the preset requirements according to the random vibration stress detection results and the swept frequency vibration stress detection results, and optimize the brackets to be optimized according to the random vibration stress detection results and the swept frequency vibration stress detection results.

9. A vibration detection optimization system for a support structure as claimed in claim 8, characterized in that: The vibration detection module comprises: a vibration detection unit; The vibration detection unit is used to perform random vibration detection on the whole machine model according to a preset random vibration detection method, in combination with the modal frequency and the vibration mode of the bracket, calculate the stress value and fatigue life of the bracket, and obtain the random vibration stress detection result of the bracket; According to a preset sweep frequency vibration detection method, a sweep frequency vibration detection is performed on the whole machine model in combination with the modal frequency and the bracket vibration shape, the resonance point of the bracket is identified, and the sweep frequency vibration stress detection result of the bracket is obtained.

10. A vibration detection optimization system for a support structure as claimed in claim 9, characterized in that: The vibration detection unit comprises: a frequency sweep vibration detection subunit; The sweep frequency vibration detection subunit is used to determine the sweep frequency range according to the modal frequency, and determine the sweep frequency interval according to the sweep frequency range; According to the modal frequency and the vibration shape of the bracket, a frequency sweep vibration test is performed on the whole machine model by using a preset finite element simulation tool to obtain a measured frequency sweep frequency and a stress curve of the bracket; According to the measured sweep frequency and the stress curve, the whole machine model is subjected to a sweep vibration test through the finite element simulation tool to identify the resonance point of the bracket and obtain a sweep vibration stress test result of the bracket.

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