Method for predicting fatigue life by energy method considering machined surface integrity

Abstract

The invention discloses a method for predicting fatigue life by an energy method considering machined surface integrity, and belongs to the technical field of life prediction of high-strength steel materials, and the method comprises the following steps: obtaining geometric-mechanical-metallurgical properties before a fatigue test; obtaining hysteresis loop data and fatigue life data of different circulation cycles; obtaining a revision coefficient of the surface topography and the surface hardness to the total energy through a micro-crack non-propagation threshold value; obtaining a surface layer residual compressive stress energy revision coefficient considering different depths; importing the revision coefficient of the total energy into a surface layer residual compressive stress energy revision coefficient item of a single-cycle energy density-life method; obtaining one-cycle plastic strain energy when the fatigue test is stable through a back stress equation; and realizing fatigue life prediction and characterization of the material under different processing surface integrity parameters by adopting a correction single-cycle cycle energy density-life method. The method effectively solves the problem of life prediction of the material under the action of different surface integrity of medium and low cycle fatigue.

Description

technical field [0001] The invention belongs to the technical field of life prediction of high-strength steel materials, and more specifically relates to a method for predicting fatigue life using an energy method considering the integrity of a machined surface. Background technique [0002] The energy method is widely used because it solves the fatigue life problem from the most essential mechanism of fatigue damage and can explain many fatigue phenomena that cannot be explained by other methods. However, in the prediction of many energy methods at home and abroad, most of the material properties are studied by ignoring the integrity of the machined surface. Experiments show that the fatigue life ignoring the integrity of the machined surface layer often affects the prediction accuracy of the energy method. [0003] Therefore, how to provide an energy-based method for predicting fatigue life considering the integrity of the machined surface is an urgent problem to be solved...

AI Technical Summary

Problems solved by technology

[0004] In view of this, the present invention provides a method for predicting the fatigue life of the energy method considering the integrity of the machined

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