关键词: 冷加工, 残余应力, 周期载荷, 衰减, 破坏性试验, 叠栅干涉条纹

Abstract: The destructive experimental study of such attenuation in the title presents greater dif-ficulties because those specimens expanded by the same process often differ in initial values of residual stresses from one another.Up to now few or no such experimental study has been re- ported in the open literature. An exploration experimental study is proposed for hard-aluminum alloy LY12CZ sheet specimens with a cold expanded(4.23%)hole,using 100 lines/ mm Moire' gratings and with the specimens cut after fatigue test.The cut is perpendicular to the applied load and in parallel with the diaineter of a hole. The distance between the cut and the diameter is 1～ 2mm. In the measurement of a strain,these values at the left and right edges of a hole and those values in a group of specimens are averaged respectively. A satisfactory result of the experiment is obtained.A redistribution of residual stress(in the form of a strain)at the edge of a hole with higher cold expansion under applied cycle loading is presented.

Key words: cold working, residual stress, cyclic loads, fringesattenuaUOndestructive tests- Moire