CN114117627A

CN114117627A - Vehicle frame strength analysis method, device, medium and equipment

Info

Publication number: CN114117627A
Application number: CN202111316192.3A
Authority: CN
Inventors: 郑伟成; 高新路; 杨科彪; 程录波; 董银飞; 王远哲; 司冈田
Original assignee: Beiqi Foton Motor Co Ltd
Current assignee: Beiqi Foton Motor Co Ltd
Priority date: 2021-11-08
Filing date: 2021-11-08
Publication date: 2022-03-01

Abstract

The utility model relates to a frame intensity analysis method, device, medium and equipment, belongs to the vehicle field, need not multidisciplinary joint simulation can realize the intensity analysis of frame, has reduced the degree of difficulty of frame intensity analysis. A frame strength analysis method comprises the following steps: establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame; establishing front and rear suspension models of the frame by utilizing the nonlinear unit; establishing a finite element model of a frame and a finite element model of a cargo box bottom plate assembly; connecting parts connected with the frame and container floor assembly in the vehicle to a frame finite element model and a container floor assembly finite element model in a model mode, and connecting the frame finite element model and the container floor assembly finite element model to a front suspension and a rear suspension to form a nonlinear frame strength CAE analysis model; and solving the nonlinear frame strength CAE analysis model under the preset nonlinear analysis working condition to obtain a frame strength analysis result.

Description

Vehicle frame strength analysis method, device, medium and equipment

Technical Field

The present disclosure relates to the field of vehicles, and in particular, to a method, an apparatus, a medium, and a device for analyzing a frame strength.

Background

Since the frame transmits forces of a cargo box and a cab to front and rear suspensions and is a main load-bearing member in a vehicle, the strength performance of the frame is an important index of the fatigue durability of the vehicle. However, the frame connecting parts are numerous and complex in connecting mode, and the CAE analysis of the frame strength is difficult due to the nonlinear parts such as the plate spring, the buffer block and the limiting structure.

In the related art, a frame strength CAE analysis method is based on load extraction and inertial release. That is, by utilizing Adams software, a vehicle dynamics model is established, and load is extracted by carrying out dynamic simulation on working conditions such as jolt, brake, turning and torsion, so that the force on external connection points such as a frame, a suspension and a vehicle body is obtained; then, a finite element model of the frame is established by using Nastran software, the extracted load is applied to the external connection point of the frame, and the frame strength is calculated by an inertia release method.

However, the analysis method needs to establish a vehicle dynamics complete vehicle model to extract load and perform inertia release finite element strength analysis on the vehicle frame, so that the two disciplines of vehicle dynamics and finite element analysis are needed to be combined and simulated, the technical capability requirement is higher, and the difficulty of the vehicle frame strength analysis is increased.

Disclosure of Invention

The invention aims to provide a method, a device, a medium and equipment for analyzing the strength of a vehicle frame, which can analyze the strength of the vehicle frame without multidisciplinary joint simulation and reduce the difficulty of analyzing the strength of the vehicle frame.

In order to achieve the above object, the present disclosure provides a frame strength analysis method, including: establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame; establishing front and rear suspension models of the frame by using the nonlinear unit; establishing a finite element model of a frame and a finite element model of a cargo box bottom plate assembly; connecting a part connected with the frame and the container floor assembly in the vehicle to the frame finite element model and the container floor assembly finite element model in a model mode, and connecting the frame finite element model and the container floor assembly finite element model to the front suspension and the rear suspension to form a nonlinear frame strength CAE analysis model; and solving the non-linear frame strength CAE analysis model under a preset non-linear analysis working condition to obtain a strength analysis result of the frame.

Optionally, if the nonlinear component is a leaf spring, the establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame includes: establishing a sheet body or an entity unit to simulate each plate spring according to the thickness of each plate spring by taking a plate spring CAD digital model as a reference; a gap unit for simulating contact between the leaf springs is established between the leaf springs, wherein the sheet or solid unit and the gap unit are used as a nonlinear unit simulating the leaf springs.

Optionally, if the nonlinear component is a buffer block, the establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame includes: the method comprises the steps that a compression test of a real object buffer block is utilized, force and displacement relation curve data of the buffer block in the compression test are obtained, and the idle stroke distance of the buffer block in a suspension system is determined; and establishing a nonlinear unit for simulating the buffer block by using the force-displacement relation curve data and the idle stroke distance.

Optionally, if the nonlinear component is a limiting structure, the establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame includes: and establishing a nonlinear unit for simulating the limiting structure according to the idle stroke distance of the limiting structure and the rigidity of the connecting piece near the limiting structure.

Optionally, the establishing a front and rear suspension model of the vehicle frame by using the nonlinear unit includes: simulating front and rear axles of the front and rear suspensions according to the size of the axle housing, and establishing a leaf spring lifting lug finite element model; and connecting the plate spring, the buffer block and the limiting structure to establish the front and rear suspension models.

Optionally, the connecting the part of the vehicle connected to the frame and cargo floor assembly to the finite element frame model and the finite element cargo floor assembly model in a model form comprises: connecting components of the vehicle connected to the frame and cargo floor assembly to the finite element frame model and the finite element cargo floor assembly model in mass point units.

Optionally, the preset nonlinear analysis working condition is established by: and defining a load set of the frame and setting the preset nonlinear analysis working condition according to a use scene, test field road surface information, a designed maximum centripetal acceleration and a tire maximum adhesion coefficient.

The present disclosure also provides a frame strength analysis device, including: the first establishing unit is used for establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame; the second establishing unit is used for establishing front and rear suspension models of the frame by utilizing the nonlinear unit; the third establishing unit is used for establishing a finite element model of the frame and a finite element model of the cargo box bottom plate assembly; a fourth establishing unit, configured to connect a component of the vehicle connected to the frame and cargo box floor assembly to the finite element frame model and the finite element cargo box floor assembly model in a model form, and connect the finite element frame model and the finite element cargo box floor assembly model to the front and rear suspensions, so as to form a nonlinear frame strength CAE analysis model; and the analysis unit is used for solving the nonlinear vehicle frame strength CAE analysis model under the preset nonlinear analysis working condition to obtain the strength analysis result of the vehicle frame.

The present disclosure also provides a non-transitory computer readable storage medium having stored thereon a computer program which, when executed by a processor, implements the steps of the method according to the present disclosure.

The present disclosure also provides an electronic device, comprising: a memory having a computer program stored thereon; a processor for executing the computer program in the memory to implement the steps of the method according to the present disclosure.

By adopting the technical scheme, because the nonlinear unit for simulating the nonlinear component of the frame is established, the front and rear suspension models of the frame are established by utilizing the nonlinear unit, the finite element model of the frame and the finite element model of the container bottom plate assembly are established, the component connected with the frame and the container bottom plate assembly in the vehicle is connected to the finite element model of the frame and the finite element model of the container bottom plate assembly in a model form, the finite element model of the frame and the finite element model of the container bottom plate assembly are connected to the front and rear suspensions, and the CAE analysis model of the nonlinear frame strength is solved under the preset nonlinear analysis working condition to obtain the strength analysis result of the frame, the CAE simulation analysis of a single subject of the frame can be realized only by finite element modeling analysis, the multidisciplinary joint simulation is not needed, the finite element analysis knowledge can be completed, the requirements on technical capability are less, and the difficulty of the strength analysis of the frame is reduced, and the influence of nonlinear components such as a plate spring, a buffer block, a limiting structure and the like on the CAE analysis of the frame strength is considered, so that the analysis result is more accurate.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description serve to explain the disclosure without limiting the disclosure. In the drawings:

FIG. 1 is a flow chart of a method of frame strength analysis according to one embodiment of the present disclosure.

Fig. 2 shows a schematic diagram of a leaf spring CAD digital model.

Figure 3 shows a leaf spring finite element model schematic.

Fig. 4 shows a partial enlarged view of a finite element model of a leaf spring.

FIG. 5 is a graphical representation of force versus displacement curve data for a bumper block during a compression test.

FIG. 6 shows a schematic of the distance of the idle travel of the bumper in the suspension system.

FIG. 7 shows a schematic diagram of a finite element model of a buffer block.

FIG. 8 shows a force versus displacement graph for a nonlinear element modeled buffer block using force versus displacement curve data and idle stroke distance.

Fig. 9 shows a CAD digital-to-analog diagram of the spacing structure.

FIG. 10 shows a schematic view of a finite element model of a spacing structure.

Figure 11 shows a force versus displacement curve for the spacing structure.

Fig. 12 shows a schematic diagram of a finite element model of a front suspension.

Fig. 13 shows a schematic diagram of a finite element model of the rear suspension.

Fig. 14 shows a schematic diagram of a nonlinear frame strength CAE analysis model.

FIG. 15 is a diagram of an exemplary non-linearity parameter card.

Fig. 16 is a schematic block diagram of a frame strength analysis apparatus according to an embodiment of the present disclosure.

FIG. 17 is a block diagram illustrating an electronic device in accordance with an example embodiment.

Detailed Description

The following detailed description of specific embodiments of the present disclosure is provided in connection with the accompanying drawings. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

FIG. 1 is a flow chart of a method of frame strength analysis according to one embodiment of the present disclosure. As shown in fig. 1, the method includes the following steps S11 to S15.

In step S11, a nonlinear unit for simulating a nonlinear component of a vehicle frame is established.

The non-linear components of the frame include leaf springs, bumpers, stop members, and the like. How to establish the non-linear cells of each non-linear element is described in detail below.

In some embodiments, if the nonlinear component is a leaf spring, it is possible to establish a sheet or solid unit to simulate each leaf spring according to the thickness of each leaf spring based on the leaf spring CAD figures, and establish a gap unit between the leaf springs for simulating contact between the leaf springs, wherein the sheet or solid unit and the gap unit are used as the nonlinear unit simulating the leaf springs. In addition, the plate spring also has rigidity requirements, so that the analysis model can be calibrated through the design rigidity of the plate spring, the material parameters of the plate spring are adjusted, the rigidity of the plate spring is ensured to be consistent with the design state, and the accuracy of the frame strength analysis is improved. Fig. 2 shows a schematic diagram of a leaf spring CAD digital model. Figure 3 shows a leaf spring finite element model schematic. Fig. 4 shows a partial enlarged view of a finite element model of a leaf spring.

In some embodiments, if the nonlinear component is a buffer block, a compression test may be performed on the physical buffer block, then a compression test of the physical buffer block may be used to obtain force-displacement relationship curve data (as shown in fig. 5) of the buffer block during the compression test, determine an idle stroke distance (as shown in fig. 6) of the buffer block in the suspension system, and then establish a nonlinear unit for simulating the buffer block by using the force-displacement relationship curve data and the idle stroke distance. FIG. 7 shows a schematic diagram of a finite element model of a buffer block. FIG. 8 shows a force versus displacement graph for a nonlinear element modeled buffer block using force versus displacement curve data and idle stroke distance.

In some embodiments, if the non-linear component is a stop structure, the non-linear unit used to simulate the stop structure may be established based on the idle stroke distance of the stop structure and the stiffness of the connector near the stop structure. Fig. 9 shows a CAD digital-to-analog diagram of the spacing structure. FIG. 10 shows a schematic view of a finite element model of a spacing structure. Figure 11 shows a force versus displacement curve for the spacing structure.

In step S12, front and rear suspension models of the vehicle frame are created using the nonlinear unit.

In some embodiments, after the nonlinear component of the nonlinear component is established, the front and rear suspension models of the vehicle frame can be established by using the nonlinear unit, that is, the front and rear axles of the front and rear suspensions can be simulated according to the size of the axle housing, a leaf spring lifting lug finite element model can be established, and then the leaf spring, the buffer block and the limiting structure are connected to establish the front and rear suspension models. Wherein the front and rear axles can be simulated using a beam unit, e.g. the Nastran software. Further, RBE2, spokes, etc. may be used in conjunction with leaf springs, bumpers and stops to create front and rear suspension models. Fig. 12 shows a schematic diagram of a finite element model of a front suspension. Fig. 13 shows a schematic diagram of a finite element model of the rear suspension.

In step S13, a finite element model of the frame and a finite element model of the cargo box floor assembly are created.

In step S14, components of the vehicle (e.g., cab, engine, fuel tank, battery, condenser, radiator, cargo, etc.) connected to the frame and bed assemblies are connected (e.g., connected using BUSH, RBE2, RBE3, etc.) in a model (e.g., in mass point units) to the finite element frame model and bed assembly model, and the finite element frame model and bed assembly model are connected to the front and rear suspensions (e.g., the front and rear suspensions may be connected using spokes), forming a nonlinear frame strength CAE analysis model. Fig. 14 shows a schematic diagram of a nonlinear frame strength CAE analysis model.

In step S15, the nonlinear frame strength CAE analysis model is solved under the preset nonlinear analysis condition, so as to obtain a frame strength analysis result.

In some embodiments, the load set of the vehicle frame (e.g., constraint, gravity, jounce acceleration, braking friction, turning centrifugal force, torsional forced displacement) and the setting of the preset non-linear analysis conditions (e.g., jounce, braking, turning, torsion, etc.) may be defined and set according to the usage scenario, test field road surface information, design maximum centripetal acceleration, maximum tire adhesion coefficient, etc.

In some embodiments, when solving the nonlinear frame strength CAE analysis model, a nonlinear parameter card may be established, which sets an incremental step size according to the model convergence; in addition, a control card may be established for controlling the solving process, for example, a solving sequence (for example, SOL 106) and other control parameters may be set in the control card. FIG. 15 is a diagram of an exemplary non-linearity parameter card. In fig. 15, NLPARM represents the control parameters for defining the iterative strategy when nonlinear static analysis, mainly using NINC; ID is the number of the NPLPARM card; the NINC is the increment number during iteration in the nonlinear analysis, can be an integer within 0-1000, and is 10 as a default; DT is the interval increment of time in the creep analysis; KMETHOD is a stiffness control method, which can be AUTO, ITER or SEMI, and defaults to AUTO (program automatically determines the most effective convergence method); KSTEP is the number of iterations at KMETHOD ═ ITER; maximum is the maximum number of iterations per load increment; CONV is a convergence criteria identifier that can take U, P or W, and combinations thereof, and defaults to PW; INTOUT is an output control flag, which can be YES, NO or ALL, and is NO by default; YES is the output result of each load increment, NO is the output result of the last step only; EPSU is displacement error (U); EPSP is the load error (P); EPSW is the working error (W), and the default values are all 0.01; MAXDIV is the number of divergent iterations, with a default value of 3; the MAXQN is the maximum number of the correction vectors for storing the Quasi-Newton; MAXLS is the maximum number of searches for each iteration step; FSTRESS is the effective stress component that limits the material subroutine increments; LSTOL is the line search error; MAXBIS is the maximum number of increments per bi-directional load allowed; MAXR is the maximum ratio of arc length increment relative to the initial value; RTOLB is the maximum increment angle allowed once per iteration.

Fig. 16 is a schematic block diagram of a frame strength analysis apparatus according to an embodiment of the present disclosure. As shown in fig. 16, the apparatus includes: a first establishing unit 161 for establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame; a second establishing unit 162 for establishing front and rear suspension models of the vehicle frame using the nonlinear unit; the third establishing unit 163 is used for establishing a finite element model of the frame and a finite element model of the cargo floor assembly; a fourth establishing unit 164, configured to connect components of the vehicle connected to the frame and cargo box floor assembly to the finite element model of the frame and the finite element model of the cargo box floor assembly in a model form, and connect the finite element model of the frame and the finite element model of the cargo box floor assembly to the front and rear suspensions to form a nonlinear frame strength CAE analysis model; and the analysis unit 165 is configured to solve the nonlinear vehicle frame strength CAE analysis model under a preset nonlinear analysis working condition to obtain a vehicle frame strength analysis result.

With regard to the apparatus in the above-described embodiment, the specific manner in which each module performs the operation has been described in detail in the embodiment related to the method, and will not be elaborated here.

Fig. 17 is a block diagram illustrating an electronic device 700 in accordance with an example embodiment. As shown in fig. 7, the electronic device 700 may include: a processor 701 and a memory 702. The electronic device 700 may also include one or more of a multimedia component 703, an input/output (I/O) interface 704, and a communication component 705.

The processor 701 is configured to control the overall operation of the electronic device 700, so as to complete all or part of the steps in the frame strength analysis method. The memory 702 is used to store various types of data to support operation at the electronic device 700, such as instructions for any application or method operating on the electronic device 700 and application-related data, such as contact data, transmitted and received messages, pictures, audio, video, and the like. The Memory 702 may be implemented by any type of volatile or non-volatile Memory device or combination thereof, such as Static Random Access Memory (SRAM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Erasable Programmable Read-Only Memory (EPROM), Programmable Read-Only Memory (PROM), Read-Only Memory (ROM), magnetic Memory, flash Memory, magnetic disk, or optical disk. The multimedia components 703 may include screen and audio components. Wherein the screen may be, for example, a touch screen and the audio component is used for outputting and/or inputting audio signals. For example, the audio component may include a microphone for receiving external audio signals. The received audio signal may further be stored in the memory 702 or transmitted through the communication component 705. The audio assembly also includes at least one speaker for outputting audio signals. The I/O interface 704 provides an interface between the processor 701 and other interface modules, such as a keyboard, mouse, buttons, etc. These buttons may be virtual buttons or physical buttons. The communication component 705 is used for wired or wireless communication between the electronic device 700 and other devices. Wireless Communication, such as Wi-Fi, bluetooth, Near Field Communication (NFC), 2G, 3G, 4G, NB-IOT, eMTC, or other 5G, etc., or a combination of one or more of them, which is not limited herein. The corresponding communication component 705 may thus include: Wi-Fi module, Bluetooth module, NFC module, etc.

In an exemplary embodiment, the electronic Device 700 may be implemented by one or more Application Specific Integrated Circuits (ASICs), Digital Signal Processors (DSPs), Digital Signal Processing Devices (DSPDs), Programmable Logic Devices (PLDs), Field Programmable Gate Arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components for performing the frame strength analysis method described above.

In another exemplary embodiment, a computer readable storage medium comprising program instructions which, when executed by a processor, implement the steps of the frame strength analysis method described above is also provided. For example, the computer readable storage medium may be the memory 702 described above that includes program instructions executable by the processor 701 of the electronic device 700 to perform the frame strength analysis method described above.

The preferred embodiments of the present disclosure are described in detail with reference to the accompanying drawings, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all belong to the protection scope of the present disclosure.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. In order to avoid unnecessary repetition, various possible combinations will not be separately described in this disclosure.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.

Claims

1. A frame strength analysis method is characterized by comprising the following steps:

establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame;

establishing front and rear suspension models of the frame by using the nonlinear unit;

establishing a finite element model of a frame and a finite element model of a cargo box bottom plate assembly;

connecting a part connected with the frame and the container floor assembly in the vehicle to the frame finite element model and the container floor assembly finite element model in a model mode, and connecting the frame finite element model and the container floor assembly finite element model to the front suspension and the rear suspension to form a nonlinear frame strength CAE analysis model;

and solving the non-linear frame strength CAE analysis model under a preset non-linear analysis working condition to obtain a strength analysis result of the frame.

2. The method of claim 1, wherein the non-linear member is a leaf spring, and establishing a non-linear unit for simulating a non-linear member of a vehicle frame comprises:

establishing a sheet body or an entity unit to simulate each plate spring according to the thickness of each plate spring by taking a plate spring CAD digital model as a reference;

a gap unit for simulating contact between the leaf springs is established between the leaf springs, wherein the sheet or solid unit and the gap unit are used as a nonlinear unit simulating the leaf springs.

3. The method of claim 1, wherein the nonlinear component is a bumper, and the establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame comprises:

the method comprises the steps that a compression test of a real object buffer block is utilized, force and displacement relation curve data of the buffer block in the compression test are obtained, and the idle stroke distance of the buffer block in a suspension system is determined;

and establishing a nonlinear unit for simulating the buffer block by using the force-displacement relation curve data and the idle stroke distance.

4. The method of claim 1, wherein the non-linear component is a restraint structure, and the establishing a non-linear unit for simulating a non-linear component of a vehicle frame comprises:

and establishing a nonlinear unit for simulating the limiting structure according to the idle stroke distance of the limiting structure and the rigidity of the connecting piece near the limiting structure.

5. The method of claim 1, wherein said modeling front and rear suspension of said vehicle frame using said nonlinear element comprises:

simulating front and rear axles of the front and rear suspensions according to the size of the axle housing, and establishing a leaf spring lifting lug finite element model;

and connecting the plate spring, the buffer block and the limiting structure to establish the front and rear suspension models.

6. The method of claim 1, wherein the attaching the components of the vehicle to the frame and cargo box floor assembly in a model to the finite element frame model and the finite element cargo box floor assembly model comprises:

connecting components of the vehicle connected to the frame and cargo floor assembly to the finite element frame model and the finite element cargo floor assembly model in mass point units.

7. The method of claim 1, wherein the predetermined nonlinear analysis condition is established by:

and defining a load set of the frame and setting the preset nonlinear analysis working condition according to a use scene, test field road surface information, a designed maximum centripetal acceleration and a tire maximum adhesion coefficient.

8. A frame strength analysis device, characterized by comprising:

the first establishing unit is used for establishing a nonlinear unit for simulating a nonlinear component of a vehicle frame;

the second establishing unit is used for establishing front and rear suspension models of the frame by utilizing the nonlinear unit;

the third establishing unit is used for establishing a finite element model of the frame and a finite element model of the cargo box bottom plate assembly;

a fourth establishing unit, configured to connect a component of the vehicle connected to the frame and cargo box floor assembly to the finite element frame model and the finite element cargo box floor assembly model in a model form, and connect the finite element frame model and the finite element cargo box floor assembly model to the front and rear suspensions, so as to form a nonlinear frame strength CAE analysis model;

and the analysis unit is used for solving the nonlinear vehicle frame strength CAE analysis model under the preset nonlinear analysis working condition to obtain the strength analysis result of the vehicle frame.

9. A non-transitory computer readable storage medium, on which a computer program is stored, which, when being executed by a processor, carries out the steps of the method according to any one of claims 1 to 7.

10. An electronic device, comprising:

a memory having a computer program stored thereon;

a processor for executing the computer program in the memory to carry out the steps of the method of any one of claims 1 to 7.