基于位移场的裂纹尖端识别算法

提出一种基于位移场的裂纹尖端识别算法。首先建立了与裂尖位置有关的目标函数,将裂尖识别问题转化为求解最小值的优化问题；然后在位移场范围内假设裂尖位置,将非线性优化问题转变为线性问题,在给出裂尖的初始假设位置后,通过该裂尖识别算法迭代分析,最终获得裂纹尖端的准确位置。仿真测试表明,该算法6s内通过4步迭代分析就可以得到Ⅰ型裂纹区域的位移场和Ⅰ-Ⅱ混合型裂纹区域的位移场准确的裂尖位置,该方法为裂纹测量技术提供了技术支持,有极大的应用价值。 

Locating the crack tip algorithm based on displacement field

An algorithm of locating the crack tip based on displacement filed around crack tip was proposed. Give the problem of locating the crack tip,the solution was tured to solving the minimum value by building the objective function including crack tip location firstly. And then the location of crack tips was assumed in a format of mesh, nonlinear optimal problem can be analyzed through a linear least squares approach after an assuming crack tip was chosen. The exact crack tip was gotten by iterative analysis. The results show that this algorithm has converged to the Ⅰ-mode and Ⅰ-Ⅱ mix-mode exact crack tip during four iterative steps in six seconds. The algorithm can provide technical assistance for crack measurement technique and has high engineering values.