基于无网格法梁结构多裂纹定量识别

Multi-crack detection of beam structures based on meshless method

研究基于无网格法的悬臂梁结构多裂纹定量识别方法。通过局部加权残量法将裂纹以虚拟边界融入离散系统方程,建立多裂纹梁结构动力学模型,获得定量识别正问题数据库。结合曲率模态法先找到裂纹位置,再以实测频率作为反问题输入利用粒子群法反演寻优从而定量预测出裂纹的损伤程度。数值仿真表明,该方法前处理简单,适合用来模拟非连续裂纹问题,为结构多裂纹识别提供了新途径。

Multi-crack of a cantilever beam structure were detected based on the meshless method. With the local weighted residual method,cracks were taken as virtual boundaries to be integrated into a discrete system＇s equations to build a multi-crack beam dynamic model and acquire a data base for identifying quantitatively a positive problem.Combined with the curvature modal analysis method,the crack positions were found. The measured frequencies were taken as inputs,the particle swarm optimization method was used for the optimization of an inverse problem to predict quantitatively the damage level of cracks. Namerical simulations showed that the proposed method is simple and suitable for simulating non-continuous crack problems,and it provides a new way for detecting multi-crack of structures.