交变载荷下孔边残余应力变化规律的无损研究

Non distructive Study on Residual Stress of Cold Expanded Hole under Cyclic Loading

用高灵敏度的云纹干涉法，无损研究了冷挤孔边残余应力在交变载荷下的变化规律。使用１２００线／ｍｍ的闪耀正交光栅，实时测量了冷挤孔边正交方向上因残余应力衰减而引起的应变量，估算出了这些方向上的残余应力的衰减量，并研究了不同挤压量下的残余应力衰减规律。试验研究表明，ＬＹ１２ＣＺ试件的孔边残余应力在交变载荷作用下发生了衰减，孔边残余应力的衰减量受挤压量影响，挤压量越大，孔边的残余应力相对衰减量就越小。

High sensitivity Moirè interferometry has been used to measure attenuation of residual stress of cold expanded hole under cyclic loading. 1200line/mm Moirè cross grating is used to measure on the time the attenuation of the residual stress around the expanded hole along vertical direction and horizontal direction of specimen. The study shows that residual stress around a cold expanded hole under applied cyclic loading is attemuated at predeternined cycles in this paper, and the larger the expanded degree is, the smaller the attenuation will be. Residual stress is easily attenuated aroud the hole in the vertical diretion of specimen.