Dynamic stiffness analysis method and device for MPV servicing vehicle body

Abstract

The embodiment of the invention provides an MPV servicing vehicle body dynamic stiffness analysis method, device and equipment and a computer readable storage medium. The method comprises the following steps: acquiring a first system matrix of a reordered MPV servicing vehicle body and a reordered first external steady-state excitation vector; converting the first system matrix into a second system matrix through a constructed projection model; converting the first external steady-state excitation vector into a second external steady-state excitation vector based on the position of a non-zero element in the first external steady-state excitation vector; calculating a residual vector based on the second system matrix and a second external steady-state excitation vector; calculating a global residual vector based on the residual vector; based on the global residual vector, dynamic stiffness analysis of the MPV servicing vehicle body is completed, in this way, efficient scheduling and solving of large-scale residual vector tasks under hundreds of working conditions are achieved, and the overall calculation efficiency and the resource utilization rate of frequency response analysis are remarkably improved.

Description

Technical Field

[0001] Embodiments of the present application relate to the field of data processing, and particularly to a dynamic stiffness analysis method, device, equipment, and computer-readable storage medium for an MPV fully assembled body. Background Art

[0002] The dynamic stiffness analysis of an MPV fully assembled body is an important part of the vehicle NVH performance evaluation. Its goal is to obtain the steady-state response characteristics of the body structure under typical excitation loads, so as to guide the body structure stiffness design, vibration reduction and noise reduction optimization, and vehicle comfort improvement.

[0003] Currently, in the dynamic stiffness analysis of an MPV fully assembled body, various industrial software generally adopts a frequency-domain calculation process based on the modal superposition method. In this process, the solution of the residual vector is usually processed by directly solving a system of linear equations or using an explicitly constructed projection matrix. In recent years, the automatic multi-substructure algorithm (AMLS) has been gradually introduced into the frequency response analysis. However, the current existing solutions are mainly based on the explicit projection method, that is, directly using the global projection matrix to perform forward and backward transformations on the residual terms. Although the above approach has a certain dimension reduction effect, when facing the typical simulation requirements of an MPV body model (including multiple excitation points and multiple frequency conditions), the large number of matrix multiplications, data access, and storage operations required for explicit projection will bring huge computational and memory overheads, which will severely limit the overall dynamic stiffness calculation efficiency and make it difficult to meet the requirements of high performance and fast response for large-scale engineering simulations. Summary of the Invention

[0004] According to the embodiments of the present application, a dynamic stiffness analysis solution for an MPV fully assembled body is provided. By implicitly performing vector transformation and linear equation solution in a low-dimensional substructure space, the high computational and memory overheads caused by explicitly constructing and storing the projection matrix are effectively avoided. When dealing with multiple excitation load points or frequency conditions in the typical analysis scenario of an MPV vehicle, the method of the present invention supports batch parallel solution of the residual vector, can greatly improve the single-condition calculation efficiency on the premise of maintaining the accuracy of dynamic stiffness analysis, significantly optimize the total time-consuming of engineering simulations, and has excellent parallel expansion ability and hardware resource adaptability. That is, the method of the present invention can show advantages such as small computational overhead and easy parallel implementation in the dynamic stiffness analysis of an MPV vehicle structure, can be adapted to the existing platform, and is particularly suitable for the efficient engineering simulation requirements of body dynamic stiffness response analysis and NVH characteristic optimization.

[0005] In the first aspect of the present application, a dynamic stiffness analysis method for an MPV fully assembled body is provided. The method includes: Obtain the first system matrix of the MPV fully assembled body after reordering, and the first external steady-state excitation vector after reordering; Convert the first system matrix into a second system matrix through the constructed projection model; based on the positions of non-zero elements in the first external steady-state excitation vector, convert the first external steady-state excitation vector into a second external steady-state excitation vector; Calculate a residual vector based on the second system matrix and the second external steady-state excitation vector; Calculate a global residual vector based on the residual vector; complete the dynamic stiffness analysis of the MPV body-in-white based on the global residual vector.

[0006] In some embodiments, the converting the first system matrix into a second system matrix through the constructed projection model includes: Calculate a projection matrix of a substructure based on the obtained working condition data; Calculate a projection model based on the projection matrix of the substructure; Convert the first system matrix into a second system matrix based on the projection model.

[0007] In some embodiments, the calculating a projection matrix of a substructure based on the obtained working condition data includes: ; where V i is the eigenvector of the i-th substructure; Ns is the number of substructures; A i are all ancestor nodes of substructure i; Ψ ij is the constraint mode matrix between substructure i and substructure j; I is the identity matrix.

[0008] In some embodiments, the converting the first external steady-state excitation vector into a second external steady-state excitation vector based on the positions of non-zero elements in the first external steady-state excitation vector includes: Obtain the positions of non-zero elements in the first external steady-state excitation vector; Construct a first structure combination based on the positions of the non-zero elements; Traverse the first structure combination, and construct a second structure set based on each substructure in the first structure combination and all ancestor nodes corresponding to each substructure; Convert the first external steady-state excitation vector into a second external steady-state excitation vector based on the second structure set.

[0009] In some embodiments, the calculating a residual vector based on the second system matrix and the second external steady-state excitation vector includes: Calculate a modal space load vector based on the second system matrix and the second external steady-state excitation vector; Calculate a loss load vector based on the second external steady-state excitation vector and the modal space load vector; Calculate a projection matrix based on the second system matrix and the loss load vector; Calculate eigenvectors based on the projection matrix and the second system matrix; Calculate a residual vector based on the projection matrix and the eigenvectors;

[0010] In some embodiments, calculating the eigenvectors based on the projection matrix and the second system matrix includes: ; Wherein, is the system stiffness matrix obtained by transforming the second system matrix through the projection matrix; is the system mass matrix obtained by transforming the second system matrix through the projection matrix; is the eigenvalue; Q is the eigenvector.

[0011] In some embodiments, calculating the global residual vector based on the residual vector includes: Calculate a global residual vector matrix based on the residual vector and the model projection matrix; Calculate the global residual vector based on the global residual vector matrix through the following formula: ; Wherein, is the global residual vector matrix; Z is the reordering transformation matrix; is the transformation matrix of the Z matrix.

[0012] In a second aspect of the present application, there is provided a dynamic stiffness analysis device for an MPV ready-to-assemble body. The device includes: An acquisition module, configured to acquire the first system matrix of the MPV ready-to-assemble body after reordering, and the first external steady-state excitation vector after reordering; A conversion module, configured to convert the first system matrix into a second system matrix through a pre-constructed projection model; and convert the first external steady-state excitation vector into a second external steady-state excitation vector based on the positions of non-zero elements in the first external steady-state excitation vector; A first calculation module, configured to calculate a residual vector based on the second system matrix and the second external steady-state excitation vector; A second calculation module, configured to calculate a global residual vector based on the residual vector; and complete the dynamic stiffness analysis of the MPV ready-to-assemble body based on the global residual vector.

[0013] In a third aspect of the present application, an electronic device is provided. The electronic device includes: a memory and a processor, where a computer program is stored on the memory, and when the processor executes the program, the method described above is implemented.

[0014] In a fourth aspect of the present application, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the method according to the first aspect of the present application is implemented.

[0015] The method for analyzing the dynamic stiffness of the MPV ready-to-assemble body provided by the embodiments of the present application includes obtaining the first system matrix of the MPV ready-to-assemble body after reordering, and the first external steady-state excitation vector after reordering; converting the first system matrix into a second system matrix through a constructed projection model; converting the first external steady-state excitation vector into a second external steady-state excitation vector based on the positions of non-zero elements in the first external steady-state excitation vector; calculating a residual vector based on the second system matrix and the second external steady-state excitation vector; calculating a global residual vector based on the residual vector; and completing the dynamic stiffness analysis of the MPV ready-to-assemble body based on the global residual vector, realizing the efficient scheduling and solution of large-scale residual vector tasks under hundreds of working conditions, and significantly improving the overall calculation efficiency and resource utilization rate of the frequency response analysis.

[0016] It should be understood that the content described in the summary of the invention is not intended to limit the key or important features of the embodiments of the present application, nor to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In combination with the drawings and referring to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present application will become more obvious. In the drawings, the same or similar reference numerals represent the same or similar elements, where: Figure 1 is a flowchart of the method for analyzing the dynamic stiffness of the MPV ready-to-assemble body according to the embodiments of the present application; Figure 2 is a schematic diagram of a substructure tree according to the embodiments of the present application; Figure 3 is a block diagram of the device for analyzing the dynamic stiffness of the MPV ready-to-assemble body according to the embodiments of the present application; Figure 4 is a schematic diagram of the structure of a terminal device or a server suitable for implementing the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0019] In addition, the term "and / or" in this text merely describes the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this text generally represents an "or" relationship between the associated objects before and after.

[0020] Figure 1 The flowchart of the dynamic stiffness analysis method for the MPV as-built body according to an embodiment of the present invention is shown. The method includes: S110, obtaining the first system matrix of the MPV as-built body after reordering, and the first external steady-state excitation vector after reordering.

[0021] The present invention can be applied to the efficient parallel scheduling and solution of the residual vector calculation tasks at multiple working condition frequency points in the dynamic stiffness analysis of the MPV as-built body. For ease of description, let the total number of working conditions involved in the dynamic stiffness analysis be m, the total number of residual vectors to be calculated in all working conditions be n, and the number of threads used in the calculation process be , and the number of substructures obtained by dividing the entire finite element model based on the automatic multi-substructure algorithm (AMLS) be . The number of residual vectors corresponding to each working condition can be flexibly set by the user according to actual simulation requirements, that is, the number of residual vectors in each working condition can be unevenly distributed and vary greatly.

[0022] In some embodiments, the basic frequency response equation for the dynamic stiffness analysis of the MPV as-built body is set: ; where s is the frequency variable; M is the finite element mass matrix of the MPV as-built body; u(s) is the steady-state response of the vehicle body structure to the excitation in the frequency domain; C is the finite element damping matrix of the MPV as-built body; K is the finite element stiffness matrix of the MPV as-built body, and f(s) is the external steady-state excitation spectrum; where M, C, and K belong to the system matrix; that is, the system matrix includes M, C, and K.

[0023] In some embodiments, the system degrees of freedom can be reordered through methods such as mesh dissection software to obtain the reordered system matrix: ; ; ; where M is the original mass matrix of the MPV's curb body; is the reordered system mass matrix; C is the original damping matrix of the MPV's curb body; is the reordered system damping matrix; K is the original stiffness matrix of the MPV's curb body; is the reordered system stiffness matrix; Z is the reordering transformation matrix, which is a permutation matrix representing the re - numbering of the system degrees of freedom; the Z matrix is not explicitly constructed in practical applications and only reflects the change in the degree - of - freedom numbering; Z T is the transpose matrix of the Z matrix; 、 、 belongs to the first system matrix; that is, the first system matrix includes 、 、 .

[0024] In some embodiments, all operating conditions are traversed. According to their respective linear constraint conditions and excitation application positions, the corresponding n steady - state excitation vectors f(s) are assembled without considering their distribution in the operating conditions. The static load - balancing strategy is used to evenly divide the n vectors into Nt threads for processing to ensure task balance (the difference is at most 1); the residual vectors processed in each thread are renumbered in the data structure so that their order is consistent with the sub - structure elimination order in AMLS. This order is based on the METIS sorting result, which is beneficial to improving the cache hit rate and promoting the reuse of sub - structure data, thereby enhancing the parallel computing efficiency, that is: ; where, is the i - th external steady - state excitation vector; is the reordered i - th external steady - state excitation vector (the first external steady - state excitation vector).

[0025] S120. Convert the first system matrix into a second system matrix through the constructed projection model; based on the positions of the non-zero elements in the first external steady-state excitation vector, convert the first external steady-state excitation vector into a second external steady-state excitation vector.

[0026] In some embodiments, project and onto a low-dimensional subspace: ; ; ; where is the re-ordered system mass matrix, is the system mass matrix with reduced dimensions after being transformed by the AMLS method; is the re-ordered system damping matrix, is the system damping matrix with reduced dimensions after being transformed by the AMLS method.

[0027] is the re-ordered system stiffness matrix, is the system stiffness matrix with reduced dimensions after being transformed by the AMLS method; 、 、 belongs to the second system matrix; that is, the second system matrix includes 、 、 ; T is the entire model projection matrix (projection model) when calculating using the AMLS method; is the transpose matrix of matrix T; it will not be explicitly calculated during the actual calculation process and can be implicitly represented in the following way: ; where is the projection matrix of the i-th substructure; is the number of substructures; Furthermore, can be calculated in the following way: ; where Vi is the eigenvector of the i-th substructure; Ns is the number of substructures; $A_i$ is all the ancestor nodes of sub-structure $i$; $\varPsi_{ij}$ is the constraint mode matrix of sub-structure $i$ and sub-structure $j$; $I$ is the identity matrix.

[0028] In summary, the implicit calculation is as follows: ; ; ; In some embodiments, for the residual vector projection method proposed by the present invention, the above-mentioned implicit strategy can also be referred to avoid constructing a large-scale dense matrix.

[0029] Specifically, project the converted vector onto the same subspace: ; is the $i$-th externally steady-state excitation vector after reordering, that is, the second externally steady-state excitation vector; Furthermore, substitute the expression of the $T$ matrix: ; In some embodiments, when has fewer non-zero elements, especially for the single-point excitation condition, when the number of non-zero elements is usually between several and dozens, the second externally steady-state excitation vector conversion can be performed in the following manner.

[0030] Specifically, count the positions of the non-zero elements in the vector, find the corresponding sub-structure id of each position in the AMLS method according to the corresponding relationship, record all sub-structures, and construct the first structure combination Set1; Traverse all the sub-structures in the set Set1, and put each sub-structure and all its corresponding ancestor nodes into the set Set2. As Figure 2 shows, if the sub-structure id in the set Set1 is only 1, the corresponding set Set2 contains the sub-structures 1, 3, 7, 15; if the sub-structure ids in the set Set1 are 1 and 11, the corresponding set Set2 contains the sub-structures 1, 3, 7, 11, 13, 14, 15; Perform the conversion of in the following manner: ; Furthermore, in order to ensure load balancing, in the present invention, when $N_t$ threads calculate the conversion of $n$ vectors, the task statement of OpenMP can be used for dynamic strategy scheduling to solve the problem that the number of non-zero elements between the vectors may vary greatly.

[0031] S130, calculate the residual vector based on the second system matrix and the second external steady-state excitation vector.

[0032] In some embodiments, when calculating the residual vector in units of working conditions, it is necessary to take into account that the number of residual vectors for each working condition may vary. Therefore, when calculating m working conditions with Nt threads, dynamic scheduling is also required, for example, the dynamic mode in the schedule statement of OpenMP.

[0033] Specifically, calculate the modal space load vector: ; where is the modal space load vector; is the external steady-state excitation vector obtained after dimensionality reduction through the AMLS method; is the eigenvector matrix of the dimensionality reduction characteristic equation calculated in the AMLS method; is the transpose matrix of the matrix; Calculate the loss load vector: ; where is the loss load vector; Solve the linear equations to calculate the projection matrix X: ; where X is the projection matrix to be solved; Solve the generalized eigenvalue: ; where is the eigenvalue; Q is the eigenvector; Calculate the dimensionality reduction residual vector: ; where is the dimensionality reduction residual vector.

[0034] S140, calculate the global residual vector based on the residual vector; complete the dynamic stiffness analysis of the MPV whole vehicle body based on the global residual vector In some embodiments, the global residual vector can be obtained by back substitution.

[0035] Specifically, back substitution to obtain the globally sorted residual vector after AMLS: ; Among them, is the global residual vector matrix; in actual calculation, it can be combined with the back substitution calculation of the AMLS method to better utilize the cache characteristics of the computer to improve the calculation efficiency; Furthermore, based on the degree-of-freedom correspondence relationship of the system degree-of-freedom reordering obtained in the above steps, the global residual vector in the order of the finite element degrees of freedom is obtained reversely: ; Among them, P is the global residual vector; is the transpose matrix of the Z matrix.

[0036] According to the embodiments of the present invention, the following technical effects are achieved: By identifying the set of the smallest substructures (Set1) and its ancestor set (Set2) involved in the non-zero terms of the excitation vector, the present invention significantly reduces the number of substructures participating in the projection calculation, realizes the efficient conversion of the sparse excitation vector, and effectively improves the calculation performance and storage efficiency of the reduced-dimensional load calculation in the frequency response analysis.

[0037] In the projection stage, the present invention calculates with each residual vector as a unit, does not depend on the balance of the number of residual vectors within the working conditions, supports task allocation under any distribution conditions, and evenly distributes all the residual vectors to multiple threads for execution by using static partitioning, ensuring that the number of calculation tasks for each thread is as consistent as possible.

[0038] In the calculation stage, the present invention adopts a dynamic grouping strategy based on the working conditions, and based on the task and dynamic mechanisms provided by OpenMP, supports the flexible scheduling of unequal amounts of residual vectors under hundreds of working conditions, dynamically allocates parallel thread resources, and effectively improves the overall calculation throughput rate and multi-core resource utilization rate in the multi-condition frequency response analysis.

[0039] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all optional embodiments, and the actions and modules involved are not necessarily required by the present application.

[0040] The above is the introduction of the method embodiments. The following further illustrates the solution of the present application through device embodiments.

[0041] Figure 3 shows a block diagram of the MPV full-body dynamic stiffness analysis device 300 according to an embodiment of the present application, asFigure 3 The illustration includes: An acquisition module 310, configured to acquire a first system matrix of the re - ordered MPV ready - to - assemble body and a re - ordered first external steady - state excitation vector; A conversion module 320, configured to convert the first system matrix into a second system matrix through a first preset algorithm; and convert the first external steady - state excitation vector into a second external steady - state excitation vector through a second preset algorithm; A first calculation module 330, configured to calculate a residual vector based on the second system matrix and the second external steady - state excitation vector; A second calculation module 340, configured to calculate a global residual vector based on the residual vector; and complete the dynamic stiffness analysis of the MPV ready - to - assemble body based on the global residual vector.

[0042] Those skilled in the art can clearly understand that for the convenience and conciseness of description, the specific working processes of the described modules can refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0043] Figure 4 The figure shows a schematic structural diagram of a terminal device or a server suitable for implementing the embodiments of the present application.

[0044] As Figure 4 shown, the terminal device or the server includes a central processing unit (CPU) 401, which can execute various appropriate actions and processes according to the program stored in the read - only memory (ROM) 402 or the program loaded from the storage section 408 into the random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the terminal device or the server are also stored. The CPU 401, ROM 402, and RAM 403 are connected to each other through a bus 404. The input / output (I / O) interface 405 is also connected to the bus 404.

[0045] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc. and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. The drive 410 is also connected to the I / O interface 405 as required. A removable medium 411, such as a magnetic disk, an optical disk, a magneto - optical disk, a semiconductor memory, etc., is installed on the drive 410 as required, so that the computer program read from it can be installed into the storage section 408 as required.

[0046] In particular, according to an embodiment of the present application, the above method flow steps can be implemented as a computer software program. For example, an embodiment of the present application includes a computer program product, which includes a computer program carried on a machine-readable medium, and the computer program includes program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from the network through the communication part 409, and / or installed from the removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above functions defined in the system of the present application are executed.

[0047] It should be noted that the computer-readable medium shown in the present application can be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. The computer-readable storage medium can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, the computer-readable storage medium can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device. In the present application, the computer-readable signal medium can include a data signal propagated in a baseband or as part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium, and the computer-readable medium can send, propagate, or transmit a program for use by or in combination with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium can be transmitted by any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0048] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of systems, methods, and computer program products according to various embodiments of the present application. In this regard, each block in the flowchart or block diagram may represent a module, a program segment, or a part of code that contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than that marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, as well as the combination of blocks in the block diagram and / or flowchart, can be implemented by a dedicated hardware-based system that performs the specified function or operation, or can be implemented by a combination of dedicated hardware and computer instructions.

[0049] The units or modules involved in the embodiments described in the present application can be implemented in software or in hardware. The described units or modules can also be provided in a processor. Among them, the names of these units or modules do not, in some cases, constitute a limitation on the units or modules themselves.

[0050] As another aspect, the present application also provides a computer-readable storage medium, which can be included in the electronic device described in the above embodiments; or can exist separately without being assembled into the electronic device. The above computer-readable storage medium stores one or more programs, and when the above-mentioned programs are executed by one or more processors, they implement the methods described in the present application.

[0051] The above description is only the preferred embodiments of the present application and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the foregoing application concept. For example, the technical solutions formed by mutually replacing the above features with the (but not limited to) technical features having similar functions described in the present application.

Claims

1. A dynamic stiffness analysis method for a prepared MPV body, characterized in that, Including: Obtain the first system matrix of the re - ordered MPV trimmed body and the re - ordered first external steady - state excitation vector; Through the constructed projection model, convert the first system matrix into a second system matrix; based on the positions of non - zero elements in the first external steady - state excitation vector, convert the first external steady - state excitation vector into a second external steady - state excitation vector; Based on the second system matrix and the second external steady - state excitation vector, calculate the residual vector; Based on the residual vector, calculate the global residual vector; Based on the global residual vector, complete the dynamic stiffness analysis of the MPV trimmed body.

2. The method according to claim 1, characterized in that, The step of converting the first system matrix into a second system matrix through the constructed projection model includes: Based on the obtained working condition data, calculate the projection matrix of the sub - structure; Based on the projection matrix of the sub - structure, calculate the projection model; Based on the projection model, convert the first system matrix into a second system matrix.

3. The method according to claim 2, wherein The step of calculating the projection matrix of the sub - structure based on the obtained working condition data includes: ； wherein, V i is the feature vector of the i-th sub-structure; Ns is the number of sub - structures; A i All ancestor nodes of sub-structure i; Ψ ij is the constraint mode matrix of substructure i and substructure j; I is the identity matrix.

4. The method according to claim 3, characterized in that The step of converting the first external steady - state excitation vector into a second external steady - state excitation vector based on the positions of non - zero elements in the first external steady - state excitation vector includes: Obtain the positions of non - zero elements in the first external steady - state excitation vector; Based on the positions of non - zero elements, construct the first structure combination; Traverse the first structure combination, and based on each sub - structure in the first structure combination and all ancestor nodes corresponding to each sub - structure, construct the second structure set; Based on the second structure set, convert the first external steady - state excitation vector into a second external steady - state excitation vector.

5. The method according to claim 4, wherein The step of calculating the residual vector based on the second system matrix and the second external steady - state excitation vector includes: Based on the second system matrix and the second external steady - state excitation vector, calculate the modal - space load vector; Based on the second external steady - state excitation vector and the modal - space load vector, calculate the loss load vector; Based on the second system matrix and the loss load vector, calculate the projection matrix; Based on the projection matrix and the second system matrix, calculate the eigenvector; Based on the projection matrix and the eigenvector, calculate the residual vector.

6. The method according to claim 5, wherein The step of calculating the eigenvector based on the projection matrix and the second system matrix includes: ； Among them, is the system stiffness matrix obtained after the second system matrix is transformed by the projection matrix; is the system mass matrix obtained after the second system matrix is transformed by the projection matrix; is an eigenvalue; Q is the eigenvector.

7. The method according to claim 6, characterized in that, The step of calculating the global residual vector based on the residual vector includes: Based on the residual vector and the model projection matrix, calculate the global residual vector matrix; Based on the global residual vector matrix, calculate the global residual vector through the following formula: ； Among them, is the global residual vector matrix; Z is the re - ordering transformation matrix; is the transformation matrix for the Z matrix.

8. An MPV body-in-white dynamic stiffness analysis device, characterized in that, Including: An acquisition module for obtaining the first system matrix of the re - ordered MPV trimmed body and the re - ordered first external steady - state excitation vector; A conversion module for converting the first system matrix into a second system matrix through the constructed projection model; and converting the first external steady - state excitation vector into a second external steady - state excitation vector based on the positions of non - zero elements in the first external steady - state excitation vector; A first calculation module, configured to calculate a residual vector based on the second system matrix and the second external steady-state excitation vector; A second calculation module, configured to calculate a global residual vector based on the residual vector; Based on the global residual vector, the dynamic stiffness analysis of the MPV body-in-white is completed.

9. An electronic device, comprising a memory and a processor, wherein a computer program is stored on the memory, characterized in that, When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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