Engine suspension bracket life calculation method, device, equipment and storage medium

Abstract

The invention discloses a method, device, equipment and storage medium for calculating the life of an engine suspension bracket. The method collects acceleration signals of an engine suspension bracket through an acceleration sensor, processes the acceleration signals and obtains displacement signals; determines the dynamic force on the engine suspension bracket according to the displacement signals, and obtains a force load signal in the time domain according to the dynamic force; establishes a flexible body model corresponding to the engine suspension bracket in a simulation model, inputs the force load signal into the flexible body model, obtains modal stress and modal coordinates, and determines the service life of the engine suspension bracket according to the modal stress and modal coordinates; the engine suspension bracket life calculation cycle can be reduced, the test cost can be reduced, and the actual stress condition of the frame can be better reflected through the combination of virtual and actual, the accuracy of the data is guaranteed, and the speed and efficiency of the engine suspension bracket life calculation are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of engine suspension, and in particular to a method, device, equipment and storage medium for calculating the life of an engine suspension bracket. Background Art

[0002] In the prior art, the life analysis of the brackets and support of the suspension system remains at the strength analysis stage. Through simulation analysis, a force several times that of the bracket (for example, ±10g, ±12g) is applied to the bracket in the X, Y, and Z directions. Based on the maximum stress, it is determined whether the brackets and support meet the durability requirements. The frame assembly equipped with the engine suspension system is fixed on the platform; the engine suspension system is loaded in the forward and rearward directions through the load dynamic tooling cycle, the excitation tooling is installed, the durability of the engine suspension system is verified, and the life of the suspension system support bracket is verified through the vehicle reliability test.

[0003] However, the prior art has the following disadvantages:

[0004] 1. Relying on vehicle reliability tests to verify the durability of parts has a long cycle and high cost.

[0005] 2. Bench durability test: ① Fatigue test is carried out according to the given load and fixed test frequency, which is somewhat different from the load actually borne by the bracket; ② The virtual load spectrum is obtained through virtual simulation, which is somewhat different from the actual one.

[0006] 3. Different types of vehicle models have different road load spectra, and the existing solutions do not take into account the differences in vehicle model types.

[0007] 4. Load collection method: The use of a three-force sensor requires the redesign of the bracket to combine the sensor and the bracket into a whole. The stiffness of the modified bracket may not be consistent with the original bracket. If the strain gauge method is used, the suspension bracket also needs to be redesigned, and it is difficult to achieve complete decoupling of the assembled bridge in three directions. Summary of the invention

[0008] The main purpose of the present invention is to provide an engine suspension bracket life calculation method, device, equipment and storage medium, aiming to solve the technical problems in the prior art that it is necessary to rely on vehicle reliability tests to verify the durability of vehicle parts, which has a long cycle and high cost, and the gap between the separate virtual simulation durability test and the actual load of the bracket is large, and the differences in vehicle models are not taken into account, and the load collection needs to be redesigned.

[0009] In a first aspect, the present invention provides a method for calculating the life of an engine suspension bracket, the method comprising the following steps:

[0010] The acceleration signal of the engine suspension bracket is collected by an acceleration sensor, and the acceleration signal is processed to obtain a displacement signal;

[0011] Determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force;

[0012] A flexible body model corresponding to the engine suspension bracket is established in the simulation model, the force load signal is input into the flexible body model, modal stress and modal coordinates are obtained, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0013] Optionally, collecting an acceleration signal of the engine suspension bracket by an acceleration sensor, and processing the acceleration signal to obtain a displacement signal includes:

[0014] The acceleration signal of the measuring point at the suspension of the engine suspension bracket is collected by an acceleration sensor;

[0015] removing sharp corners and burrs in the acceleration signal to obtain a processed signal;

[0016] Performing Fourier transform on the processed signal to obtain converted frequency domain data, and performing secondary integration on the frequency domain data to obtain a displacement signal.

[0017] Optionally, performing Fourier transform on the processed signal to obtain converted frequency domain data, and performing secondary integration on the frequency domain data to obtain a displacement signal comprises:

[0018] Performing Fourier transform on the processed signal to obtain transformed frequency domain data;

[0019] The frequency domain data is integrated twice to obtain the displacement signal through the following formula:

[0020]

[0021] Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

[0022] Optionally, determining the dynamic force on the engine suspension bracket according to the displacement signal, and obtaining a force load signal in the time domain according to the dynamic force, comprises:

[0023] The dynamic force on the engine suspension bracket is determined according to the displacement signal by the following formula:

[0024] F=X(K-Mω 2 )

[0025] Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency.

[0026] A force load signal in the time domain is obtained according to the dynamic force.

[0027] Optionally, obtaining a force load signal in the time domain according to the dynamic force comprises:

[0028] A force signal of the dynamic force within a preset frequency domain is obtained, and the force signal is subjected to inverse Fourier transform to obtain a force load signal in the time domain.

[0029] Optionally, establishing a flexible body model corresponding to the engine suspension bracket in the simulation model, inputting the force load signal into the flexible body model, obtaining modal stress and modal coordinates, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates includes:

[0030] Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model;

[0031] The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation:

[0032]

[0033]

[0034] in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time;

[0035] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0036] Optionally, the superimposing and calculating the modal coordinates of each order mode to obtain the modal stress, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates includes:

[0037] The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress:

[0038]

[0039] Where, M is the modal mass, ü(t) is the square of the modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force;

[0040] A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

[0041] In a second aspect, in order to achieve the above-mentioned object, the present invention further provides a device for calculating the life of an engine suspension bracket, the device for calculating the life of an engine suspension bracket comprising:

[0042] A signal acquisition and processing module, used to acquire an acceleration signal of the engine suspension bracket through an acceleration sensor, and process the acceleration signal to obtain a displacement signal;

[0043] A force load acquisition module, used to determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force;

[0044] The life calculation module is used to establish a flexible body model corresponding to the engine suspension bracket in the simulation model, input the force load signal into the flexible body model, obtain modal stress and modal coordinates, and determine the service life of the engine suspension bracket according to the modal stress and the modal coordinates.

[0045] In a third aspect, to achieve the above-mentioned purpose, the present invention further proposes an engine suspension bracket life calculation device, the engine suspension bracket life calculation device comprising: a memory, a processor, and an engine suspension bracket life calculation program stored in the memory and executable on the processor, the engine suspension bracket life calculation program being configured to implement the steps of the engine suspension bracket life calculation method as described above.

[0046] In a fourth aspect, to achieve the above-mentioned purpose, the present invention further proposes a storage medium, on which is stored an engine mount bracket life calculation program, which, when executed by a processor, implements the steps of the engine mount bracket life calculation method as described above.

[0047] The engine suspension bracket life calculation method proposed in the present invention collects the acceleration signal of the engine suspension bracket through an acceleration sensor, processes the acceleration signal to obtain a displacement signal; determines the dynamic force on the engine suspension bracket according to the displacement signal, and obtains a force load signal in the time domain according to the dynamic force; establishes a flexible body model corresponding to the engine suspension bracket in a simulation model, inputs the force load signal into the flexible body model, obtains modal stress and modal coordinates, and determines the service life of the engine suspension bracket according to the modal stress and the modal coordinates; can verify the durability of parts without relying on vehicle reliability tests, reduces the engine suspension bracket life calculation cycle, reduces testing costs, is applicable to a variety of vehicle models, does not need to repeatedly redesign simulation models, reduces analysis costs, and can better reflect the actual stress conditions of the frame through the combination of virtual and actual, ensures data accuracy, improves service life analysis efficiency, and improves the speed and efficiency of engine suspension bracket life calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present invention;

[0049] Figure 2 It is a schematic flow chart of a first embodiment of a method for calculating the life of an engine mount bracket of the present invention;

[0050] Figure 3 It is a flow chart of a second embodiment of a method for calculating the life of an engine mount bracket according to the present invention;

[0051] Figure 4 It is a schematic diagram of frame sensor data collection in the engine suspension bracket life calculation method of the present invention;

[0052] Figure 5 It is a schematic diagram of the life calculation process in the engine suspension bracket life calculation method of the present invention;

[0053] Figure 6 It is a functional module diagram of the first embodiment of the engine suspension bracket life calculation device of the present invention.

[0054] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0055] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0056] The solution of the embodiment of the present invention is mainly: collecting the acceleration signal of the engine suspension bracket through the acceleration sensor, processing the acceleration signal to obtain the displacement signal; determining the dynamic force on the engine suspension bracket according to the displacement signal, and obtaining the force load signal in the time domain according to the dynamic force; establishing a flexible body model corresponding to the engine suspension bracket in the simulation model, inputting the force load signal into the flexible body model, obtaining the modal stress and modal coordinates, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates; being able to verify the durability of parts without relying on vehicle reliability tests , reducing the engine suspension bracket life calculation cycle, reducing testing costs, and is applicable to a variety of vehicle models, without the need to repeatedly redesign the simulation model, reducing analysis costs, and through the combination of virtual and actual, it can better reflect the actual stress conditions of the frame, ensuring the accuracy of the data, improving the efficiency of service life analysis, and improving the speed and efficiency of engine suspension bracket life calculation. It solves the problem that the existing technology needs to rely on vehicle reliability tests to verify the durability of vehicle parts, which has a long cycle and high cost, and the gap between the separate virtual simulation durability test and the actual load of the bracket is large, and the differences in vehicle models are not considered, and the load collection needs to be redesigned. Technical problems.

[0057] Reference Figure 1 , Figure 1 The figure is a schematic diagram of the device structure of the hardware operating environment involved in the embodiment of the present invention.

[0058] like Figure 1 As shown, the device may include: a processor 1001, such as a CPU, a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. Among them, the communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface 1003 may also include a standard wired interface and a wireless interface. The network interface 1004 may optionally include a standard wired interface and a wireless interface (such as a Wi-Fi interface). The memory 1005 may be a high-speed RAM memory, or it may be a stable memory (Non-Volatile Memory), such as a disk memory. The memory 1005 may optionally be a storage device independent of the aforementioned processor 1001.

[0059] Those skilled in the art will understand that Figure 1 The device structure shown in the figure does not constitute a limitation of the device, and may include more or less components than shown in the figure, or combine certain components, or arrange the components differently.

[0060] like Figure 1As shown, the memory 1005 as a storage medium may include an operating device, a network communication module, a user interface module, and an engine mount bracket life calculation program.

[0061] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and performs the following operations:

[0062] The acceleration signal of the engine suspension bracket is collected by an acceleration sensor, and the acceleration signal is processed to obtain a displacement signal;

[0063] Determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force;

[0064] A flexible body model corresponding to the engine suspension bracket is established in the simulation model, the force load signal is input into the flexible body model, modal stress and modal coordinates are obtained, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0065] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0066] The acceleration signal of the measuring point at the suspension of the engine suspension bracket is collected by an acceleration sensor;

[0067] removing sharp corners and burrs in the acceleration signal to obtain a processed signal;

[0068] Performing Fourier transform on the processed signal to obtain converted frequency domain data, and performing secondary integration on the frequency domain data to obtain a displacement signal.

[0069] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0070] Performing Fourier transform on the processed signal to obtain transformed frequency domain data;

[0071] The frequency domain data is integrated twice to obtain the displacement signal through the following formula:

[0072]

[0073] Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

[0074] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0075] The dynamic force on the engine suspension bracket is determined according to the displacement signal by the following formula:

[0076] F=X(K-Mω 2 )

[0077] Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency.

[0078] A force load signal in the time domain is obtained according to the dynamic force.

[0079] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0080] A force signal of the dynamic force within a preset frequency domain is obtained, and the force signal is subjected to inverse Fourier transform to obtain a force load signal in the time domain.

[0081] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0082] Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model;

[0083] The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation:

[0084]

[0085]

[0086] in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time;

[0087] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0088] The device of the present invention calls the engine suspension bracket life calculation program stored in the memory 1005 through the processor 1001, and also performs the following operations:

[0089] The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress:

[0090] Mü(t)+Ku(t)=F(t)

[0091] Where, M is the modal mass, ü(t) is the square of the modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force;

[0092] A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

[0093] Through the above scheme, this embodiment collects the acceleration signal of the engine suspension bracket through the acceleration sensor, processes the acceleration signal, and obtains the displacement signal; determines the dynamic force on the engine suspension bracket according to the displacement signal, and obtains the force load signal in the time domain according to the dynamic force; establishes a flexible body model corresponding to the engine suspension bracket in the simulation model, inputs the force load signal into the flexible body model, obtains the modal stress and modal coordinates, and determines the service life of the engine suspension bracket according to the modal stress and the modal coordinates; it is not necessary to rely on the whole vehicle reliability test to verify the durability of the parts, reduces the engine suspension bracket life calculation cycle, reduces the testing cost, and is applicable to a variety of vehicle models, does not need to repeatedly redesign the simulation model, reduces the analysis cost, and through the combination of virtual and actual, can better reflect the actual stress condition of the frame, ensure the accuracy of the data, improve the efficiency of the service life analysis, and improve the speed and efficiency of the engine suspension bracket life calculation.

[0094] Based on the above hardware structure, an embodiment of a method for calculating the life of an engine suspension bracket of the present invention is proposed.

[0095] Reference Figure 2 , Figure 2 It is a flow chart of the first embodiment of the method for calculating the life of an engine mount bracket of the present invention.

[0096] In a first embodiment, the engine suspension bracket life calculation method comprises the following steps:

[0097] Step S10: collecting acceleration signals of the engine suspension bracket through an acceleration sensor, and processing the acceleration signals to obtain displacement signals.

[0098] It should be noted that the acceleration signal of the engine suspension bracket of the current vehicle to be tested can be collected by the acceleration sensor. The acceleration signal can be collected in a complete cycle, and of course, it can also be collected in real time when the vehicle to be tested is driving. This embodiment does not limit this, and then the acceleration signal is processed to obtain the displacement signal.

[0099] In the specific implementation, taking a truck as an example, the reliability test driving sequence is: highway, working condition, mountainous area, bad road, among which the bad road is subject to great impact and has a high probability of damage; the test site decomposes the bad road section, and the load is collected as shown in Table 1.

[0100] Table 1

[0101] Road Section Stone Road Pebble Road Twisted Road Washboard Road Connecting Road Total / Km length 3878 400 120 400 3435 8233

[0102] One of the complete cycle conditions is 8.233 km.

[0103] Step S20: determining the dynamic force on the engine suspension bracket according to the displacement signal, and obtaining a force load signal in the time domain according to the dynamic force.

[0104] It can be understood that the dynamic force on the engine suspension bracket can be calculated based on the displacement signal, and the force load signal in the time domain can be determined based on the dynamic force.

[0105] Furthermore, the step S20 specifically includes the following steps:

[0106] The dynamic force on the engine suspension bracket is determined according to the displacement signal by the following formula:

[0107] F=X(K-Mω 2 )

[0108] Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency.

[0109] A force load signal in the time domain is obtained according to the dynamic force.

[0110] In the specific implementation, the differential equation of the undamped motion of the suspension is:

[0111]

[0112] Among them, M is the mass matrix of the suspension system, K is the stiffness matrix of the suspension system, and F(t) is the excitation force on the suspension system.

[0113] It should be understood that the dynamic force on the bracket through the above formula, K is the dynamic stiffness of the suspension cushion, which can be obtained through bench tests. In the actual engineering calculation process, Mω is usually ignored. 2 item.

[0114] Further, the step of obtaining a force load signal in the time domain according to the dynamic force comprises the following steps:

[0115] A force signal of the dynamic force within a preset frequency domain is obtained, and the force signal is subjected to inverse Fourier transform to obtain a force load signal in the time domain.

[0116] It can be understood that the force signal in the frequency domain is obtained, and then the force load signal in the time domain can be obtained through inverse Fourier transform.

[0117] Step S30: establishing a flexible body model corresponding to the engine suspension bracket in the simulation model, inputting the force load signal into the flexible body model, obtaining modal stress and modal coordinates, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates.

[0118] It should be understood that a flexible body model corresponding to the engine suspension bracket can be established in the simulation model. The flexible body model can better reflect the actual stress conditions of the frame. The load applied to the bracket includes both the load transmitted to the bracket through the frame due to different road conditions and the load transmitted by the vibration of the engine itself. After inputting the force load signal into the flexible body model, the modal stress and modal coordinates can be obtained, and the service life of the engine suspension bracket can be determined based on the modal stress and the modal coordinates.

[0119] Furthermore, the step S30 includes the following steps:

[0120] Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model;

[0121] The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation:

[0122]

[0123]

[0124] in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time;

[0125] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0126] It should be noted that Creo (PRO / E) is a CAD design software package launched by PTC of the United States in October 2010. ANSYS software is a large-scale general-purpose finite element analysis (FEA) software developed by ANSYS of the United States. It is the fastest growing computer-aided engineering (CAE) software in the world. It can interface with most computer-aided design (CAD) software to achieve data sharing and exchange, such as Creo, NASTRAN, Algor, I-DEAS, AutoCAD, etc. It is a large-scale general-purpose finite element analysis software integrating structure, fluid, electric field, magnetic field, and acoustic field analysis.

[0127] It can be understood that the modal coordinates of each mode can be obtained through the above solution formula.

[0128] In the specific implementation, the frame model established by CREO can be imported into ANYSYS to establish the frame flexible body model, and then the suspension system model can be imported into ANSYS to establish the analysis model of the frame + suspension system.

[0129] Furthermore, the modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates, including the following steps:

[0130] The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress:

[0131] Mü(t)+Ku(t)=F(t)

[0132] Where, M is the modal mass, ü(t) is the square of the modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force;

[0133] A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

[0134] It should be noted that, according to the modal stress and the modal coordinates, a structural fatigue analysis of the engine can be performed to obtain fatigue analysis results and determine the service life of the engine suspension bracket.

[0135] In the specific implementation, by superimposing and calculating the modal coordinates of each order modal vector according to the above formula, the obtained stress cloud diagram shows that the minimum life point occurs at the connection position of the bracket and the pocket beam. The measured load spectrum is imported into the finite element model, and the modal stress and modal coordinates of the frame + suspension system are calculated. Then, the modal stress superposition is used for fatigue calculation. Generally, the minimum life point occurs at the connection position of the bracket and the pocket beam. In actual operation, the test vehicle can also be tested in the test field. The test data obtained in the test field can be used to benchmark the results, thereby ensuring that the error between the calculated results and the actual results is within the required range.

[0136] Through the above scheme, this embodiment collects the acceleration signal of the engine suspension bracket through the acceleration sensor, processes the acceleration signal, and obtains the displacement signal; determines the dynamic force on the engine suspension bracket according to the displacement signal, and obtains the force load signal in the time domain according to the dynamic force; establishes a flexible body model corresponding to the engine suspension bracket in the simulation model, inputs the force load signal into the flexible body model, obtains the modal stress and modal coordinates, and determines the service life of the engine suspension bracket according to the modal stress and the modal coordinates; it is not necessary to rely on the whole vehicle reliability test to verify the durability of the parts, reduces the engine suspension bracket life calculation cycle, reduces the testing cost, and is applicable to a variety of vehicle models, does not need to repeatedly redesign the simulation model, reduces the analysis cost, and through the combination of virtual and actual, can better reflect the actual stress condition of the frame, ensure the accuracy of the data, improve the efficiency of the service life analysis, and improve the speed and efficiency of the engine suspension bracket life calculation.

[0137] Further, Figure 3 FIG. 1 is a flow chart of a second embodiment of a method for calculating the life of an engine suspension bracket according to the present invention. Figure 3 As shown, based on the first embodiment, a second embodiment of the method for calculating the life of an engine suspension bracket of the present invention is proposed. In this embodiment, the step S10 specifically includes the following steps:

[0138] Step S11: collecting acceleration signals of measuring points at the suspension of the engine suspension bracket by means of an acceleration sensor.

[0139] It should be noted that the acceleration signal of each measuring point at the suspension of the engine suspension bracket can be collected by the acceleration sensor.

[0140] In the specific implementation, see Figure 4 , Figure 4 FIG. 1 is a schematic diagram of frame sensor data collection in the engine suspension bracket life calculation method of the present invention, as shown in FIG. Figure 4As shown, the acceleration signal can be collected by a three-axis acceleration sensor, and of course, a two-axis sensor or other types of sensors can also be used, which is not limited in this embodiment; the collection channel is confirmed, and measurement points are designed above and below the suspension, respectively, with a total of 8 points for the front and rear four suspensions and 12 points for the front and rear four points (R1, R4, L1, L4) on the frame; a three-axis acceleration sensor is used and pasted on the suspension bracket, bracket and frame to collect acceleration signals.

[0141] Step S12: remove sharp corners and burrs in the acceleration signal to obtain a processed signal.

[0142] It can be understood that after processing the collected signal and removing sharp corners and burrs, a processed signal can be obtained.

[0143] Step S13: Perform Fourier transform on the processed signal to obtain frequency domain data after transformation, and perform secondary integration on the frequency domain data to obtain a displacement signal.

[0144] It should be understood that the processed data is converted into the frequency domain through Fourier transform, and then the acceleration is integrated twice to obtain the displacement signal, the processed signal is Fourier transformed to obtain the converted frequency domain data, and the frequency domain data is integrated twice to obtain the displacement signal. The algorithm for integrating the displacement signal in the frequency domain can obtain an accurate displacement signal by eliminating the error during integration in the frequency domain.

[0145] Furthermore, the step S13 includes the following steps:

[0146] Performing Fourier transform on the processed signal to obtain transformed frequency domain data;

[0147] The frequency domain data is integrated twice to obtain the displacement signal through the following formula:

[0148]

[0149] Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

[0150] It can be understood that the processed signal is subjected to Fourier transformation to obtain the converted frequency domain data, and the frequency domain data is subjected to secondary integration to obtain the displacement signal through calculation using the above formula.

[0151] In the specific implementation, refer to Figure 5 , Figure 5FIG. 1 is a schematic diagram of a life calculation process in a method for calculating the life of an engine suspension bracket of the present invention. Figure 5 As shown, the steps of road spectrum decomposition, load collection and load processing are carried out in sequence in the test field. After the design data is input into the finite element model, the modal stress can be superimposed according to the modal stress and the modal coordinates, and then the fatigue calculation can be carried out. Finally, the test results and the fatigue calculation results can be compared. In this embodiment, the acceleration sensor can be attached to the suspension bracket to collect the acceleration signal, and then the displacement is obtained by integral calculation. The relative displacement is multiplied by its suspension stiffness coefficient to obtain the force load. The algorithm of integrating the acceleration signal in the frequency domain to obtain the displacement signal is adopted. By eliminating the error during integration in the frequency domain, an accurate displacement signal is obtained; the modal coordinates of each order mode can be obtained by the modal coordinate solution formula, and then the modal coordinates of each order modal vector are converted according to the displacement modal coordinate conversion formula By performing superposition calculations and importing the measured load spectrum into the finite element model, the modal stress and modal coordinates of the frame + suspension system can be calculated. The modal stress superposition is then used to perform fatigue calculations. The results are benchmarked through tests in the test field to ensure that the error between the calculated results and the actual results is within the required range.

[0152] Through the above scheme, this embodiment collects the acceleration signal of the measuring point at the suspension of the engine suspension bracket through the acceleration sensor; removes the sharp corners and burrs in the acceleration signal to obtain a processed signal; performs Fourier transform on the processed signal to obtain the converted frequency domain data, and performs secondary integration on the frequency domain data to obtain a displacement signal. By eliminating the error during integration in the frequency domain, an accurate displacement signal can be obtained, thereby ensuring the accuracy of the data and improving the efficiency of service life analysis.

[0153] Accordingly, the present invention further provides a device for calculating the life of an engine suspension bracket.

[0154] Reference Figure 6 , Figure 6 It is a functional module diagram of the first embodiment of the engine suspension bracket life calculation device of the present invention.

[0155] In a first embodiment of the engine mount bracket life calculation device of the present invention, the engine mount bracket life calculation device comprises:

[0156] The signal acquisition and processing module 10 is used to acquire the acceleration signal of the engine suspension bracket through the acceleration sensor, and process the acceleration signal to obtain the displacement signal.

[0157] The force load acquisition module 20 is used to determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force.

[0158] The life calculation module 30 is used to establish a flexible body model corresponding to the engine suspension bracket in the simulation model, input the force load signal into the flexible body model, obtain modal stress and modal coordinates, and determine the service life of the engine suspension bracket according to the modal stress and the modal coordinates.

[0159] The signal acquisition and processing module 10 is also used to collect acceleration signals of the measuring points at the suspension of the engine suspension bracket through an acceleration sensor; remove sharp corners and burrs in the acceleration signal to obtain a processed signal; perform Fourier transform on the processed signal to obtain converted frequency domain data, and perform secondary integration on the frequency domain data to obtain a displacement signal.

[0160] The signal acquisition and processing module 10 is further used to perform Fourier transform on the processed signal to obtain converted frequency domain data;

[0161] The frequency domain data is integrated twice to obtain the displacement signal through the following formula:

[0162]

[0163] Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

[0164] The force load acquisition module 20 is further used to determine the dynamic force on the engine suspension bracket according to the displacement signal by using the following formula:

[0165] F=X(K-Mω 2 )

[0166] Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency.

[0167] A force load signal in the time domain is obtained according to the dynamic force.

[0168] A force load signal in the time domain is obtained according to the dynamic force.

[0169] The force load acquisition module 20 is further used to acquire the force signal of the dynamic force within a preset frequency domain, and perform inverse Fourier transform on the force signal to obtain a force load signal in the time domain.

[0170] The life calculation module 30 is also used to establish a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model;

[0171] The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation:

[0172]

[0173]

[0174] in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time;

[0175] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates;

[0176] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0177] The life calculation module 30 is also used to

[0178] The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress:

[0179] Mü(t)+Ku(t)=F(t)

[0180] Where, M is the modal mass, ü(t) is the square of the modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force;

[0181] A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

[0182] The steps implemented by the functional modules of the engine mount bracket life calculation device may refer to the various embodiments of the engine mount bracket life calculation method of the present invention, and will not be described in detail here.

[0183] In addition, an embodiment of the present invention further provides a storage medium, wherein the storage medium stores an engine mount bracket life calculation program, and when the engine mount bracket life calculation program is executed by a processor, the following operations are implemented:

[0184] The acceleration signal of the engine suspension bracket is collected by an acceleration sensor, and the acceleration signal is processed to obtain a displacement signal;

[0185] Determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force;

[0186] A flexible body model corresponding to the engine suspension bracket is established in the simulation model, the force load signal is input into the flexible body model, modal stress and modal coordinates are obtained, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0187] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0188] The acceleration signal of the measuring point at the suspension of the engine suspension bracket is collected by an acceleration sensor;

[0189] removing sharp corners and burrs in the acceleration signal to obtain a processed signal;

[0190] Performing Fourier transform on the processed signal to obtain converted frequency domain data, and performing secondary integration on the frequency domain data to obtain a displacement signal.

[0191] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0192] Performing Fourier transform on the processed signal to obtain transformed frequency domain data;

[0193] The frequency domain data is integrated twice to obtain the displacement signal through the following formula:

[0194]

[0195] Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

[0196] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0197] The dynamic force on the engine suspension bracket is determined according to the displacement signal by the following formula:

[0198] F=X(K-Mω 2 )

[0199] Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency.

[0200] A force load signal in the time domain is obtained according to the dynamic force.

[0201] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0202] A force signal of the dynamic force within a preset frequency domain is obtained, and the force signal is subjected to inverse Fourier transform to obtain a force load signal in the time domain.

[0203] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0204] Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model;

[0205] The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation:

[0206]

[0207]

[0208] in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time;

[0209] The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

[0210] Furthermore, when the engine suspension bracket life calculation program is executed by the processor, the following operations are also implemented:

[0211] The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress:

[0212] Mü(t)+Ku(t)=F(t)

[0213] Where M is the modal mass, The quadratic modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force;

[0214] A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

[0215] Those skilled in the art will appreciate that all or part of the steps in the above-mentioned implementation method can be accomplished by instructing related hardware through a program, and the program is stored in a storage medium, including a number of instructions for enabling a device (which may be a single-chip microcomputer, chip, etc.) or a processor to execute all or part of the steps of the method described in each implementation method of the present application; and the aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0216] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0217] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0218] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for calculating the life of an engine suspension bracket, characterized in that: The engine suspension bracket life calculation method includes: The acceleration signal of the engine suspension bracket of the vehicle to be tested is collected by an acceleration sensor, and the acceleration signal is processed to obtain a displacement signal; Determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force; Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model, inputting the force load signal into the flexible body model, obtaining modal stress and modal coordinates, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates; The method includes collecting an acceleration signal of the engine suspension bracket of the vehicle to be tested by an acceleration sensor, processing the acceleration signal, and obtaining a displacement signal, including: The acceleration signal of the measuring point of the engine mounting bracket of the vehicle to be tested is collected by an acceleration sensor; removing sharp corners and burrs in the acceleration signal to obtain a processed signal; Performing Fourier transformation on the processed signal to obtain frequency domain data after transformation, and performing secondary integration on the frequency domain data to obtain a displacement signal; The processing signal is subjected to Fourier transformation to obtain the transformed frequency domain data, and the frequency domain data is subjected to secondary integration to obtain the displacement signal, including: Performing Fourier transform on the processed signal to obtain transformed frequency domain data; The frequency domain data is integrated twice to obtain the displacement signal through the following formula: Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

2. The engine mount bracket life calculation method according to claim 1, characterized in that: Determining the dynamic force on the engine suspension bracket according to the displacement signal, and obtaining a force load signal in the time domain according to the dynamic force, comprises: The dynamic force on the engine suspension bracket is determined according to the displacement signal by the following formula: F=X(K-Mω 2 ) Wherein, F is the dynamic force on the engine suspension bracket, K is the dynamic stiffness of the suspension cushion, X is the displacement signal, M is the mass of the bracket, ω 2 is the square of the frequency, A force load signal in the time domain is obtained according to the dynamic force.

3. The engine mount bracket life calculation method according to claim 2, characterized in that: The step of obtaining a force load signal in the time domain according to the dynamic force comprises: A force signal of the dynamic force within a preset frequency domain is obtained, and the force signal is subjected to inverse Fourier transform to obtain a force load signal in the time domain.

4. The engine mount bracket life calculation method according to claim 1, characterized in that: The method of establishing a flexible body model corresponding to the engine suspension bracket in the simulation model, inputting the force load signal into the flexible body model, obtaining modal stress and modal coordinates, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates comprises: Establishing a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model; The force load signal is input into the flexible body model, and the modal coordinates of each mode are obtained by solving the following equation: in, is the modal vector matrix, ε(t) is the modal coordinate, u(t) is the modal displacement, T is the sign of the matrix transpose, M is the mass matrix, is the quadratic modal coordinate, K is the stiffness matrix, P(t) is the force vector in the force load signal, and t is time; The modal coordinates of each order mode are superimposed and calculated to obtain the modal stress, and the service life of the engine suspension bracket is determined according to the modal stress and the modal coordinates.

5. The engine mount bracket life calculation method according to claim 4, characterized in that: The method of superimposing and calculating the modal coordinates of each order mode to obtain the modal stress, and determining the service life of the engine suspension bracket according to the modal stress and the modal coordinates, comprises: The modal coordinates of each mode are superimposed and calculated using the following formula to obtain the modal stress: Where M is the modal mass, The quadratic modal displacement, K is the modal matrix, u(t) is the modal displacement, and F(t) is the modal force; A structural fatigue analysis is performed according to the modal stress and the modal coordinates to obtain a fatigue analysis result, and the service life of the engine suspension bracket is determined according to the fatigue analysis result.

6. An engine suspension bracket life calculation device, characterized in that: The engine suspension bracket life calculation device comprises: A signal acquisition and processing module, used to acquire the acceleration signal of the engine suspension bracket of the current vehicle to be tested through an acceleration sensor, and process the acceleration signal to obtain a displacement signal; A force load acquisition module, used to determine the dynamic force on the engine suspension bracket according to the displacement signal, and obtain a force load signal in the time domain according to the dynamic force; A life calculation module is used to establish a flexible body model corresponding to the frame model and the suspension model in the engine suspension bracket in the simulation model, input the force load signal into the flexible body model, obtain modal stress and modal coordinates, and determine the service life of the engine suspension bracket according to the modal stress and the modal coordinates; The method includes collecting an acceleration signal of the engine suspension bracket of the vehicle to be tested by an acceleration sensor, processing the acceleration signal, and obtaining a displacement signal, including: The acceleration signal of the measuring point of the engine mounting bracket of the vehicle to be tested is collected by an acceleration sensor; removing sharp corners and burrs in the acceleration signal to obtain a processed signal; Performing Fourier transformation on the processed signal to obtain frequency domain data after transformation, and performing secondary integration on the frequency domain data to obtain a displacement signal; The processing signal is subjected to Fourier transformation to obtain the transformed frequency domain data, and the frequency domain data is subjected to secondary integration to obtain the displacement signal, including: Performing Fourier transform on the processed signal to obtain transformed frequency domain data; The frequency domain data is integrated twice to obtain the displacement signal through the following formula: Wherein, X is the displacement signal, Γ is the integral symbol, t is time, a(τ) is the acceleration signal in the time domain, dτ is the microvariable of time, A(ω) is the displacement data in the frequency domain, j is a unit imaginary number, ω is the frequency, A(0) is the displacement value when the frequency is 0, and δ(ω) is the unit pulse function.

7. An engine suspension bracket life calculation device, characterized in that: The engine mount bracket life calculation device comprises: a memory, a processor, and an engine mount bracket life calculation program stored in the memory and executable on the processor, wherein the engine mount bracket life calculation program is configured to implement the steps of the engine mount bracket life calculation method according to any one of claims 1 to 5.

8. A storage medium, characterized in that: The storage medium stores an engine mount bracket life calculation program, and when the engine mount bracket life calculation program is executed by the processor, the steps of the engine mount bracket life calculation method according to any one of claims 1 to 5 are implemented.

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