Weld joint fatigue life prediction method

Abstract

The invention provides a weld joint fatigue life prediction method, which comprises the following steps of obtaining node force and moment of a weld joint unit node through analysis by finite element software; then, according to the identical power application principle, obtaining the corresponding linear force and moment through the calculation by the node force and the moment of the weld joint unit node; obtaining the normal structure stress and the shearing structure stress in the thickness direction of the weld joint through conversion calculation; performing correction according to the actual expansion angle of cracks in the thickness direction; obtaining a corresponding equivalent stress intensity factor through the calculation on the corrected normal structure stress and shearing structure stress, and thus obtaining an average equivalent stress intensity factor on the practical crack expansion path; and using the average equivalent stress intensity factor as an evaluation parameter of the weld joint fatigue service. The weld joint fatigue life prediction method has the beneficial effects that the solution of a large-scale matrix equation is not needed, so that the calculation efficiency is greatly improved; and the method has the advantages of high calculation efficiency and high prediction precision.

Description

technical field [0001] The invention relates to the field of welding, in particular to a high-precision fatigue life prediction method for welds. Background technique [0002] The welded structure has the advantages of high joint strength, large design flexibility, good sealing, easy processing and connection, high yield and easy automation. At present, welding is the most important connection method in engineering production, and the weight of the welded structure has accounted for It accounts for more than half of the total steel output, and this proportion is close to 70% in industrially developed countries. Welded connections are also widely used in the automotive industry and are one of the main connection methods for automobile frames and chassis. The fatigue strength of welded structures determines the durability of welded components. According to statistics, in recent years, 85% of the fatigue problems of automobile frames and chassis are related to welding structu...

AI Technical Summary

Problems solved by technology

[0004] Aiming at the problems existing in the existing welding seam fatigue life prediction method that the simulated force does not match the actual situation and the prediction accuracy is low, the present invention proposes a new welding seam fatigue life prediction method, which can accurately reflect the actual acceptance situation , to more accurately predict the fatigue life of the weld

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