RESIDUAL STRESS MEASURING METHOD, ELASTIC CRITICAL STRESS MEASURING METHOD, RESIDUAL STRESS MEASURING DEVICE AND ELASTIC CRITICAL STRESS MEASURING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a residual stress measuring method that can measure the residual stress without destroying an elastic-plastic material.SOLUTION: In a predetermined measuring area of the surface of a measurement object, an average altitude is measured in a state of not applying stress and a state of applying the stress to the measurement object, and an average altitude incremental per unit load is calculated. This is performed while increasing the stress in a stepwise manner, and the stress when the average altitude incremental per unit load is increased is assumed as the elastic critical stress of the measurement object. The measurement of the elastic critical stress is performed to an elastic-plastic material not having residual stress and the elastic-plastic material having the residual stress, and a difference between the elastic critical stress of the elastic-plastic material not having the residual stress and the elastic critical stress of an elastic-plastic material having the residual stress is assumed as the residual stress.SELECTED DRAWING: Figure 1