基于小波有限元的悬臂梁裂纹遗传优化辨识

利用小波有限元法求解了裂纹悬臂梁的前三阶固有频率，并将其拟合成以裂纹位置和深度作为变量的频响函数曲面。将裂纹识别中的匹配追踪问题转化为多维优化问题，以实测固有频率作为输入，利用遗传算法寻优求解出与输入值相差最小的样本点，进而预测出裂纹的位置和深度。试验研究表明，所提出的裂纹识别方法具有较好的精度和鲁棒性，且易于推广到诸如转子、叶片等复杂结构的裂纹监测诊断场合。

Identification of crack for cantilever beams based on wavelet finite element method and genetic algorithm

The natural frequencies of cantilever beams with various crack locations and depths were accurately obtained by means of wavelet finite element method,and the surface-fitting technique was employed to approximate the frequency response functions. Measured natural frequencies were used in a crack detection process and the crack location and size were identified through using genetic algorithm. The experimental results verify the validity of the method,and provide a powerful evidence for practical application.