Virtual simulation method for judging bolt breakage under collision working condition

Abstract

The invention discloses a virtual simulation method for judging bolt breakage under a collision working condition. The method comprises the following steps: S1, creating a bolt virtual mesh model, S2,generating a pre-tightening beam unit, applying axial pre-tightening force to the bolt; S3, generating a beam unit for representing the mechanical property of the bolt; S4, reading the historical load output curve of the bolt under the collision working condition, comparing a result with an allowable safety load according to a bolt failure criterion, and judging whether the bolt has a fracture risk or not; S5, adding failure parameters to the bolt with the fracture risk, and simulating a virtual simulation condition of bolt fracture after collision. The bolt virtual grid model created by themethod is high in simulation degree, can effectively evaluate whether the bolt is broken or not under the collision working condition, and can also simulate the effect that the broken bolt is separated from the mounting hole.

Description

technical field [0001] The invention belongs to the technical field of automobile virtual performance research and development, and in particular relates to a virtual simulation method for judging bolt fracture under collision conditions. Background technique [0002] China Insurance Automobile Safety Index (C-IASI) test and evaluation system is the most important factor in car model pricing. From the standpoint of consumers and from the perspective of auto insurance, it conducts crashworthiness research around "car damage" and "personal injury" in auto insurance accidents. Test and evaluation of the four indexes of safety and maintenance economy, safety of occupants in the car, safety of pedestrians outside the car, and vehicle auxiliary safety. [0003] The crash test is a test condition of the China Insurance Automobile Safety Index for the occupant safety index in the car, and it is used to investigate the collision accident because only a small part of the car body part...

AI Technical Summary

Problems solved by technology

[0004] In the prior art, when evaluating the sheet metal strength around the bolt holes, the bolts and nuts are simplified as a Constrained Nodal Rigid Body (rigid connection unit), and the diameter of the constrained nodal rigid body connection is consistent with the diameter of the flange, such as figure 2 As shown in the middle right, the advantage of this simplified method is that it is suitable for large-scale analysis, but the disadvantage is that it cannot be used to predict the risk of bolt breakage and simulate the effect of bolt breakout from the mounting hole

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