用密栅云纹实验解析法研究方板对角拉伸的起皱过程

本文采用密栅云纹实验解析法研究方板对角拉伸的起皱过程，得到了在起皱临界状态下的位移，应变和应力的全场的瞬间和连续变化信息。发现了起皱是局部的塑性失稳现象，它与横向压力分布的区域性和区域不均匀性直接相关，它可为研究大型覆盖件成形缺陷机理开辟一条新的途径。

A Study of Wrinkling Process of Square Sheet Metals Subjected to Diagonal Tension with Moire Topography

The moire topography analysis method was applied to the study of wrinkling process of square sheet metals subjected to diagonal tension. Informations were obtained of both the instantaneous and the continuous displacement, strain and stress of whole measured field in the course of deformation process, including those at critical wrinkling state as well. It was found that wrinkling was a phenomenon of local plastic instability and it directly related to the transverse compress stress distribution regionalization and the nonuniformity in each region. The technique discribed in the paper would open up the way to the study of the machanism of forming defect of large automobile panel.