A Multiaxial Fatigue Life Prediction Model

Abstract

The invention relates to a multi-axis fatigue life prediction model, which solves the shear strain at different orientation angles α and different time t at the dangerous part of the thin-walled member, and obtains the change history diagram of the shear strain at the dangerous part of the thin-walled member; through the change history diagram, The main critical plane and the subcritical plane, the azimuthal angles are α max 、α t ; Calculate the average additional strengthening influence factor in the loading cycle on the subcritical surface; combine the strain parameters on the main critical surface to solve the main equivalent strain on the critical surface; the parameters obtained on the critical plane are the main equivalent strain, and the subcritical The parameters obtained on the plane are corrected strains, and the two are synthesized into equivalent strains; combined with the equivalent strains and the Manson-Coffin equation, the multiaxial fatigue life of the structure is solved. The invention starts from the principle of additional strengthening in the process of multi-axial loading, and proposes a new multi-axial fatigue life prediction model, which has higher accuracy and wider material adaptability.

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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