Finite element information merging method for structural member

Abstract

A structural part finite element information merging method comprises the steps that all areas needing to be merged and area endpoints are determined in a detail finite element model of a structural part, and the areas are processing areas; searching a detail finite element model node of an end point of the processing area, wherein the node is an operation node; recording coordinates of the detail finite element model of the operation node and displacement data of a detail finite element model result; constructing a finite element with the same shape as the processing area according to the operation node to form a merging unit; the formed merging unit is endowed with the same attribute as the processing area detail finite element model; applying displacement data of detail finite element model nodes to operation nodes of the merging unit, and calculating information of the merging unit according to a finite element theory; and taking the information of the merging unit as finite element information of the processing area to complete finite element information merging.

Description

Technical Field

[0001] The present invention belongs to the technical field of strength calculation, and specifically relates to a method for merging finite element information of a structural part, and relates to a method for equivalently merging geometric and mechanical information of multiple finite elements of a structural part. Background Art

[0002] The most commonly used method in the industry for strength simulation analysis of structural parts is the finite element method. The finite element method is a numerical analysis method that discretizes the continuous solution domain into a finite number of units and uses the approximate solution of the finite element to approximate the real physical system under given constraints. The finite element is the smallest solution domain with geometric and physical properties after the solution domain is discretized. Currently, more and more strength calculations use detailed finite element models to capture the local strength data of structural parts, but the calculation results of the detailed finite element model cannot directly extract the overall strength data of the structural parts, such as the overall stress of the structure, the total load of the components and other information. In the processing of engineering problems, overall data is often required for comparative analysis or engineering verification.

[0003] There are currently two main methods to solve this problem: one is to rebuild the overall finite element model, which is a very labor-intensive, time-consuming and labor-intensive method; the other is to extract the detailed finite element information one by one and then merge them numerically. This method is computationally intensive and prone to errors due to different information output coordinate systems and other factors.

[0004] The current method of unit information merging is difficult to meet the actual needs of engineering. Summary of the invention

[0005] The purpose of the present invention is to provide a method for merging finite element information of a structural part, which can accurately and quickly complete the merging of unit information.

[0006] A method for merging finite element information of a structural part, wherein the detailed finite element model of the structural part is known, and the method is characterized in that the method comprises the following contents: 1) determining all regions and region endpoints to be merged in the detailed finite element model of the structural part, wherein the region is a processing region; 2) finding the detailed finite element model node of the processing region endpoint, wherein the node is an operation node; 3) recording the detailed finite element model coordinates of the operation node and the displacement data of the detailed finite element model result; 4) constructing a finite element of the same shape as the processing region according to the operation node to form a merged unit; 5) assigning the same properties as the detailed finite element model of the processing region to the formed merged unit; 6) applying the displacement data of the detailed finite element model node recorded in step 3) to the operation node of the merged unit, and calculating the information of the merged unit according to the finite element theory; 7) using the information of the merged unit as the finite element information of the processing region to complete the merging of the finite element information.

[0007] The advantages of the present invention are: 1) the theory is mature and complete, the operation is simple and feasible, and the program is easy to implement; 2) the detailed finite element model calculation can be accurately and quickly used for overall strength verification.

[0008] The present application is further described in detail below in conjunction with the accompanying drawings of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram of an example of merging quadrilateral units of the present invention.

[0010] Figure 2 It is a schematic diagram of the merged unit.

[0011] Explanation of numbers in the figure: 1 Detailed finite element model, 2 Processing area, 3 First operation node, 4 Second operation node, 5 Third operation node, 6 Fourth operation node. DETAILED DESCRIPTION

[0012] Referring to the accompanying drawings, the method for merging finite element information of a structural part of the present application, when the detailed finite element model of the structural part is known, the specific operation steps are as follows:

[0013] 1) In the detailed finite element model 1 of the structural part, all the regions and the region endpoints to be merged are determined, and the region is the processing region 2; the processing region 2 in the embodiment is a quadrilateral, and the selected detail elements of the processing region 2 have the same attributes. According to actual needs, the processing region can also be other shapes such as: line segment, triangle, quadrilateral, wedge, hexahedron, etc., but the shape of the selected processing region 2 meets the shape characteristics of the finite element calculation, and the region endpoints of the selected processing region 2 must have displacement data.

[0014] 2) Search for the detail finite element model node at the end point of the processing area 2 in the detail finite element model 1. This node is an operation node. The quadrilateral processing area 2 of the embodiment has four operation nodes, namely the first operation node 3, the second operation node 4, the third operation node 5, and the fourth operation node 6.

[0015] 3) According to the detailed finite element model 1, record the detailed finite element model coordinates of each operation node and the coordinates, translational displacement, and rotational displacement data of the detailed finite element model results; as shown in Table 1.

[0016] Table 1

[0017] Operation Node Coordinate / mm Translational displacement / mm Rotational displacement / rad First operating node [400，600，0] ＜0.742，0.742，－0.368＞ <3.52e-4, 3.52e-4, -5.62e-3> Second operating node [600，600，0] ＜0.771，0.771，－0.368＞ <3.52e-4, -3.52e-4, 0> The third operation node [600，400，0] ＜0.742，0.742，－0.368＞ <-3.52e-4, -3.52e-4, 5.62e-3> Fourth operation node [400，400，0] ＜0.771，0.771，－0.368＞ <-3.52e-4, 3.52e-4, 0>

[0018] 4) constructing a finite element of the same shape as the processing area 2 according to all operation nodes to form a merged element;

[0019] 5) The formed merged unit is given the same properties as the finite element model of the processing area details; the merged unit is given the parameters of the processing area unit: elastic modulus is 71000MPa, Poisson's ratio is 0.3, and thickness is 1.0mm.

[0020] 6) Apply the corresponding displacement data of the detail finite element model nodes recorded in step 3) to the operating nodes of the merged unit, and calculate the information of the merged unit according to the finite element theory.

[0021] 7) Finally, the information of the merged unit is used as the finite element information of the processing area to complete the finite element information merging.

Claims

1. A method for merging finite element information of a structural part, wherein a detailed finite element model of the structural part is known, characterized in that The method comprises the following contents: 1) determining all regions and region endpoints to be merged in the detailed finite element model of the structural part, and the region is the processing region; 2) finding the detailed finite element model node of the processing region endpoint, and the node is the operation node; 3) recording the detailed finite element model coordinates of the operation node and the displacement data of the detailed finite element model result; 4) constructing a finite element of the same shape as the processing region according to the operation node to form a merged unit; 5) assigning the same properties as the detailed finite element model of the processing region to the formed merged unit; 6) applying the displacement data of the detailed finite element model node recorded in step 3) to the operation node of the merged unit, and calculating the information of the merged unit according to the finite element theory; 7) The information of the merged unit is used as the finite element information of the processing area to complete the finite element information merging.

2. The method for merging finite element information of a structural part according to claim 1, characterized in that: In step 1), the detail elements of the selected processing area have the same attributes.

3. The method for merging finite element information of a structural part according to claim 1, characterized in that: In step 1), the shape of the selected processing area conforms to the external features calculated by finite element method.

4. The method for merging finite element information of a structural part according to claim 1, characterized in that: In step 1), the region endpoints of the selected processing region must have displacement data.

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