Finite element method and strength evaluation method for bolt

Abstract

The invention relates to a finite element method and a strength evaluation method for a bolt and belongs to the technical field of bolt strength evaluation. The finite element method and the strength evaluation method for the bolt can be applied to rapid modeling and strength evaluation of a large number of bolts under the condition of complicated structures and complicated loads. The strength evaluation method comprises the steps that a bolt stress finite element analysis result is read; a cross section parallel to a nut is established in the middle of a screw, and the tension and bending moment on the cross section under different load steps are extracted; a curve chart is made with the tension of the screw as the horizontal coordinate and the bending moment of the screw as the longitudinal coordinate; the bending moment of the bolt reaches a peak value along with the increase of the tension of the bolt; the bending moment of the bolt starts to be reduced along with the continuous increase of the tension of the bolt, and it is indicated that the bolt enters the yield stage; it is indicated that the bolt reaches the ultimate strength when the bending moment of the bolt reduces to half of the peak value along with further increase of the tension of the bolt. Bolt stress is calculated with the finite element method, a bolt strength criterion is established, and the precision of bolt strength calculation is improved.

Description

technical field [0001] The invention relates to a bolt finite element analysis method and a strength evaluation method, which can be used for rapid modeling and strength evaluation of a large number of bolts under complex structures and complex loads, and belongs to the technical field of bolt strength evaluation. Background technique [0002] Bolts are widely used in multi-type launch vehicles, and the evaluation of bolt strength is an important task. The traditional analysis uses engineering algorithms, which can quickly estimate the bolt strength, but the accuracy is low: the bolt force analysis has a strong nonlinear effect, and the change of the fulcrum of the contact surface caused by the deformation of the connected parts has a decisive impact on the bolt force. This engineering algorithm It cannot be considered; in addition, the force transmission path under complex structures and complex loads is very complicated, and it is difficult for engineering algorithms to ma...

AI Technical Summary

Problems solved by technology

The traditional analysis uses engineering algorithms, which can quickly estimate the bolt strength, but the accuracy is low: the bolt force analysis has a strong nonlinear effect, and the change of the fulcrum of the contact surface caused by the deformation of the connected parts has a decisive impact on the bolt force. This engineering algorithm It cannot be considered; in addition, the force transmission path under complex structures and complex loads is very complicated, and it is difficult for engineering algorithms to make reasonable assumptions

The finite element method can obtain a more realistic force transmission path and the load bearing distribution of each bolt, and can also simulate the nonlinear effect of the contact surface more accurately, with high precision; A large amount of time for personnel greatly affects the development process

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