Study Of Measuring Residual Stress By Indentation Strain Method Based On Finite Element Simulation

Residual stress has a great influence on the quality and service life ofengineering structure. It can make material canker, craze and reduce fatigue strengthof material, still affect property of physics and mechanics. Because it destroysstructural intension, many accidents have occurred. Study and measurement ofresidual stress has important practical significance to production and scientific test.To this day, the methods of measuring residual stress have had more than ten, andseparated into two kinds. One is the method of automatically mechanical releasing,the other is the method of nondestructive testing. The first method is to make the partrelease residual stress, and then calculating residuals tress is based on strain. Itsprecision is high, but it is destructive for material. The second method is composed ofX ray method, neutron diffraction method, magnetism method, ultrasonic method,electron spot intervening method, metal magnetism memory method. These methodsare expensive, but nondestructive for material.Indentation strain method is a residual stress measurement method based onhardness testing method. Indentation strain measurement is a very valuablemeasurement technique, which is nondestructive, rapid and cost-effective with highprecision.This paper is based on finite element simulation to analyze the residual stressversus strain increment curve, and then is compared with result of indentation straintest. They are very accordant. The results show that the estimating residual stressbased on indentation strain test is feasible, the error of which is less than5%. Thenselect the better model, which can get the results convenient, exact, fast. At lastanalysis the error of indentation position, get a residual stress versus strain incrementcurve, use which can getting the right results.