CAE (Computer Aided Engineering) analysis method for rear protection strength of commercial vehicle

Abstract

The invention discloses a CAE analysis method for commercial vehicle rear protection strength, and relates to the technical field of commercial vehicle strength analysis, and the method comprises the steps: building a basic finite element model of a rear protection and a frame which do not comprise bolts; establishing a bolt model; bolt pre-tightening force information is established; and establishing contact connection between the bolt model and the basic finite element model. According to the method, the bolt model in the finite element simulation modeling of the rear protection impact analysis is refined, and the bolt model with simplified connection is not used in the modeling, so that the deviation of strength analysis possibly caused by inaccurate model establishment is basically eliminated, and the accuracy of strength analysis is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of strength analysis of commercial vehicles, and particularly relates to a CAE analysis method for the strength of the rear protection of commercial vehicles. Background Art

[0002] In the existing simulation analysis of the impact strength of the rear protection of commercial vehicles, a finite element model is first established, and then loading analysis is carried out according to the test-specified load.

[0003] Among them, the bolt connections between the impact models are all simplified connections, and the calculation process is simple. However, there are certain differences between the simplified connection method and the real model, resulting in inaccurate analysis.

[0004] Furthermore, for the connection method of the loading head, there is no technical content in the prior art to control the direction of the connection degrees of freedom of the loading head. And the unclear setting of the degrees of freedom may lead to inconsistent numbers of released degrees of freedom of the connection of the loading head in the simulation analysis and the detected actual released degrees of freedom directions. As a result, there are deviations between the analysis results and the detection results. Summary of the Invention

[0005] The present application provides a CAE analysis method for the strength of the rear protection of commercial vehicles to solve at least one technical problem existing in the related art.

[0006] According to one aspect of the embodiments of the present application, a CAE analysis method for the strength of the rear protection of commercial vehicles is provided, including: establishing a basic finite element model of the rear protection and the vehicle frame without bolts; establishing a bolt model; establishing bolt pre-tightening force information; establishing a contact connection between the bolt model and the basic finite element model.

[0007] As an optional implementation manner, the establishing of the bolt model includes: establishing a bolt solid mesh model; inputting the material properties and material curves of the bolt model.

[0008] As an optional implementation manner, the establishing of the bolt pre-tightening force information includes: adding prestress to the bolt model; establishing the bolt pre-tightening force information according to the prestress.

[0009] As an optional implementation manner, the adding of prestress to the bolt model includes: determining the prestress of the bolt; establishing a bolt prestress curve according to the prestress; establishing a bolt prestress loading section; establishing a bolt PART set.

[0010] As an optional implementation manner, the establishing of the bolt pre-tightening force information according to the prestress includes: establishing the bolt pre-tightening force information according to the bolt prestress curve, the bolt prestress loading section and the bolt PART set.

[0011] As an alternative implementation, the determination of the prestress of the bolt includes: determining the bolt pre-tightening force according to the bolt pre-tightening force lookup table; σ = F / A, where σ is the prestress of the bolt, F is the bolt pre-tightening force, and A is the effective cross-sectional area of the bolt.

[0012] As an alternative implementation, it further includes: introducing a loading model; establishing the contact between the loading head and the rear protection model; setting the degrees of freedom of the loading head.

[0013] As an alternative implementation, the setting of the degrees of freedom of the loading head includes: restricting the translational freedoms in the Y and Z directions, releasing the translational freedom in the X direction, and releasing the rotational freedoms in the X, Y, and Z directions.

[0014] As an alternative implementation, in the material parameter card of the loading head, set CMO to 1, CON1 to 5, and CON2 to 0.

[0015] In the embodiments of the present application, a CAE analysis method for the rear protection strength of commercial vehicles is provided, which is characterized by including: establishing a basic finite element model of the rear protection and the vehicle frame without bolts; establishing a bolt model; establishing bolt pre-tightening force information; establishing a contact connection between the bolt model and the basic finite element model. The bolt model in the finite element simulation modeling of the rear protection impact analysis is refined, greatly improving the accuracy of the strength analysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present invention and used together with the specification to explain the principles of the present invention.

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0018] Figure 1 It is a schematic flowchart of an alternative CAE analysis method for the rear protection strength of commercial vehicles provided according to the embodiments of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to enable those skilled in the art to better understand the solutions of the present application, the following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0020] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of this application are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of this application described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0021] In the existing simulation analysis of the impact strength of commercial vehicle rear guards, a finite element model is first established, and then loading analysis is carried out according to the test specified load.

[0022] Among them, the bolt connections between the impact models are all simplified connections, and the calculation process is simple. However, there are certain differences between the simplified connection method and the real model, resulting in inaccurate analysis.

[0023] Furthermore, for the connection method of the loading head, there is no technical content in the prior art for controlling the direction of the connection degrees of freedom of the loading head. And the unclear setting of the degrees of freedom may lead to inconsistent numbers of degrees of freedom released by the connection of the loading head in the simulation analysis and the number of directions of degrees of freedom actually detected. Furthermore, it leads to a deviation between the analysis result and the detection result.

[0024] Therefore, as Figure 1 shown, the embodiments of this application provide a CAE analysis method for the strength of commercial vehicle rear guards, including:

[0025] S1 Establish a basic finite element model of the rear guard and the vehicle frame without bolts;

[0026] S2 Establish a bolt model;

[0027] S3 Establish bolt pre-tightening force information;

[0028] S4 Establish a contact connection between the bolt model and the basic finite element model.

[0029] Among them, it should be noted that this application does not limit the specific order of the above steps, and can be selected according to the actual situation.

[0030] The bolt model in the finite element simulation modeling of the refined rear protection impact analysis is refined. In the modeling, the bolt model with simplified connection is no longer used, and the deviation of strength analysis caused by inaccurate model establishment is basically eliminated, greatly improving the accuracy of strength analysis. At the same time, it also includes establishing bolt pre-tightening force information, which can further refine the bolt model and improve the accuracy of analysis.

[0031] Specifically, the bolt model can be established by establishing a bolt solid mesh model and inputting the material properties and material curves of the bolt model.

[0032] As an alternative implementation, the establishment of the bolt pre-tightening force information includes: adding prestress to the bolt model; establishing the bolt pre-tightening force information according to the prestress.

[0033] As an alternative implementation, the adding of prestress to the bolt model includes: determining the prestress of the bolt; establishing a bolt prestress curve according to the prestress; establishing a bolt prestress loading section; establishing a bolt PART set.

[0034] As an alternative implementation, the establishing of the bolt pre-tightening force information according to the prestress includes: establishing the bolt pre-tightening force information according to the bolt prestress curve, the bolt prestress loading section and the bolt PART set.

[0035] Specifically, bolt prestress information is added to the bolt, and the bolt pre-tightening force can be added in the form of a prestress curve. The magnitude of the prestress can be indirectly obtained from the bolt pre-tightening force. Bolt prestress loading also requires the establishment of a loading section. Specifically, the Cross Section function key can be used to select two points in the axis direction to complete the establishment of the bolt prestress loading surface. Finally, the bolt prestress information is established from the establishment of the prestress loading section, the prestress curve and the bolt PART set. To establish the prestress information, the function key INITIAL-STRESS-SECTION can be used.

[0036] As an alternative implementation, the determining of the prestress of the bolt includes: determining the bolt pre-tightening force according to the bolt pre-tightening force lookup table; σ = F / A, where σ is the prestress of the bolt, F is the bolt pre-tightening force, and A is the effective cross-sectional area of the bolt.

[0037] As an alternative implementation, it also includes: introducing a loading model; establishing the contact between the loading head and the rear protection model; setting the degrees of freedom of the loading head.

[0038] As an alternative implementation, the setting of the degrees of freedom of the loading head includes: constraining the translational freedoms in the Y and Z directions, releasing the translational freedom in the X direction, and releasing the rotational freedoms in the X, Y, and Z directions.

[0039] As an alternative embodiment, set CMO to 1, CON1 to 5, and CON2 to 0 in the material parameter card of the loading head.

[0040] The degree of freedom setting parameters are confirmed, solving the problem in the prior art that due to the lack of specific regulations on the degree of freedom setting, the number of degrees of freedom for the connection release of the loading head in the simulation analysis may be inconsistent with the number of directions of the actually detected released degrees of freedom, and improving the coincidence degree of the analysis result and the detection result.

[0041] The serial numbers of the embodiments of the present application above are only for description and do not represent the advantages or disadvantages of the embodiments.

[0042] If the integrated units in the above embodiments are implemented in the form of software function units and sold or used as independent products, they can be stored in the above-mentioned computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in the storage medium and includes several instructions for causing one or more electronic devices (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application.

[0043] In the above embodiments of the present application, the descriptions of the various embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0044] In the several embodiments provided by the present application, it should be understood that the disclosed client can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the units or modules can be in an electrical or other form.

[0045] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution provided in this embodiment.

[0046] In addition, in each embodiment of the present application, each functional unit may be integrated into a processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above integrated unit may be implemented in the form of hardware or in the form of a software functional unit.

[0047] In the above embodiments of the present application, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0048] The above are only the preferred embodiments of the present application. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present application, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A CAE analysis method for the rear protection strength of commercial vehicles, characterized in that: include: Establish a basic finite element model of the rear guard and frame excluding the bolts; Build bolt model; Establish bolt preload information; A contact connection between the bolt model and the basic finite element model is established.

2. The CAE analysis method for rear protection strength of commercial vehicles according to claim 1, characterized in that: The bolt model establishment comprises: Establish a bolt solid mesh model; Enter the material properties and material curve for the bolt.

3. The CAE analysis method for the rear protection strength of a commercial vehicle according to claim 1, characterized in that: The establishing of bolt preload information includes: Adding prestress to the bolt model; The bolt preload information is established according to the preload force.

4. The CAE analysis method for the rear protection strength of a commercial vehicle according to claim 3, characterized in that: Adding prestress to the bolt model comprises: Determine the prestressing force of the bolts; Establishing a bolt prestress curve according to the prestress; Establish bolt prestressing loading section; Create a bolt PART set.

5. The CAE analysis method for the rear protection strength of commercial vehicles according to claim 4, characterized in that: The establishing of the bolt preload force information according to the preload force comprises: The bolt prestressing force information is established according to the bolt prestressing curve, the bolt prestressing loading section and the bolt PART set.

6. The CAE analysis method for the rear protection strength of a commercial vehicle according to claim 4, characterized in that: Determining the prestress of the bolt comprises: Determine the bolt preload force according to the bolt preload force query table; σ=F / A Among them, σ is the prestress of the bolt, F is the bolt preload, and A is the effective cross-sectional area of ​​the bolt.

7. The CAE analysis method for rear protection strength of commercial vehicles according to claim 1, characterized in that: Also includes: Introduce loading model; Establish the contact between the loading head and the rear protection model; Set the loading head degrees of freedom.

8. The CAE analysis method for the rear protection strength of a commercial vehicle according to claim 7, characterized in that: The setting of the loading head freedom comprises: constraining the translational freedom in the Y direction and the Z direction, releasing the translational freedom in the X direction, and releasing the rotational freedom in the X direction, the Y direction and the Z direction.

9. The CAE analysis method for the rear protection strength of a commercial vehicle according to claim 7, characterized in that: In the material parameter card of the loading head, set CMO to 1, CON1 to 5, and CON2 to 0.

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