Multi-axial fatigue life prediction model

Abstract

The invention relates to a multi-axial fatigue life prediction model. The model is implemented through the following steps of: solving shearing strains, at different orientation angles <alpha> and different moments t, at a danger part of a thin-wall component, so as to obtain a change process diagram of the shearing strains at the dangerous part of the thin-wall component; enabling the orientationangles to be <alpha>max and <alpha>t through the change process diagram, a primary critical plane and a secondary critical plane; calculating an average additional reinforcement influence factor in aloading period on the secondary critical plane; solving a main equivalent strain on the primary critical planes by combining strain parameters on the primary critical plane; synthesizing a parametersolved on the primary critical plane and a parameter solved on the secondary critical plane into an equivalent strain, wherein the parameter solved on the primary plane is the main equivalent strain and the parameter solved on the secondary critical plane is a correction strain; and combining the equivalent strain with a Manson-Coffin equation to solve multi-axial fatigue life of the structure. Starting with a principle of generating additional reinforcement in a multi-axial loading process, the invention discloses a novel multi-axial fatigue life prediction model which is has higher precisionand wider material adaptation.

Description

technical field [0001] The invention relates to a life prediction model of mechanical components, in particular to a multi-axis fatigue life prediction model. Background technique [0002] In engineering practice, most engineering structures and mechanical parts are subjected to various forms of cyclic loads, and the load distribution mostly presents a multiaxial stress state. Even in a uniaxial external load environment, in view of the complexity of the geometry of the component, the actual load on its dangerous parts is still multi-axially distributed, and the failure mode also belongs to multi-axial fatigue failure. Therefore, under cyclic loading, the research on multiaxial fatigue is closer to engineering practice than uniaxial fatigue, and has a wider application background. [0003] The earliest multiaxial fatigue estimation methods usually equate multiaxial fatigue damage to uniaxial conditions, and then study the fatigue life prediction method under multiaxial load...

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Problems solved by technology

[0005] Aiming at the shortcomings that the existing critical plane model cannot comprehensively consider the influence of additional strengthening phenomena on the multiaxial fatigue life, and cannot be widely used in various materials, the problem to be solved by the present invention is to provide a material with higher precision and wider range An Adaptive Multiaxial Fatigue Life Prediction Model

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