基于应变非接触测量的裂纹拼接

Crack spliced based on non-contact strain measurement

使用基于图像处理的非接触网格应变测量法绘制板料成形极限图,通常选取裂纹边缘网格测量应变,测量值较理论值偏小,甚至相差较多。本文使用图像处理方法,分别建立了基于多目视觉和显微测量镜头的裂纹拼接算法,可对难变形件裂纹处网格进行拼接测量。试验结果表明,两种拼接算法均满足精度要求,前者误差为1.5%,后者为1%,对于改进成形极限图的测量方法、提高成形极限图的测量精度具有一定的参考作用。

To plot forming limit diagram of sheet metal based on the method of non-contact grid measurement using im- age processing, grids around the crack were selected to measure strain, the measurement value was smaller than theo- retical value and even having more difference. Using image processing methods, The crack spliced algorithms based on visual and microscopic measuring lens were respectively established, which could splice crack on the difficult deforma- tion sheet for measurement. The result shows that the two splicing algorithm can satisfy the requirements of precision, the error is 1.5 % and 1% respectively, it is of a certain reference for improving the method of measurement of forming limit diagram and the measuring accuracy of forming limit diagram.