用边界元法由位移场计算应变

用云纹法、散斑法等实验方法获得平面问题位移场,即u、v条纹图后,求应变(或应力)的方法有数值微分法、光学微分法和有限元法等。本文提出用边界元法从位移条纹图计算应变的方法是一种混合法。本法具有输入数据少、计算精度高、计算区域可灵活选择而不受边界影响、不需要确定绝对条纹级数等优点。

BOUNDARY ELEMENT METHODS USED TO DETERMINE STRAINS FROM THE DISPLACEMENT

There have been some methods, such as numerical differentiation, photographic differentiation and the finite element method, etc, to calculate strains from the u, v fringe patterns that obtained by means bf moire methods and speckle methods. This paper suggests a method which uses boundary element methods to calculate the strains from the prinse patterns. It is a hybrid method. This method has some advantages, sush as simple program, less input data, high accuracy, the consider domain can be selected actively and does not need determine the absolute fringe Order in the patterns.