复合材料圆筒结构脱层损伤识别研究

针对复合材料圆筒结构,讨论了基于模态柔度曲率矩阵的无损检测方法。通过模态分析获得脱层复合材料圆筒的各阶固有频率及节点振型,计算得到轴向和周向柔度曲率矩阵来判断损伤。研究表明:轴向和周向柔度曲率矩阵两种方法均可达到精确识别脱层位置及大小的效果,且越靠近外筒壁,柔度曲率矩阵图突变越大,越易检测。相对而言,轴向柔度曲率Fc在脱层位置突变远大于周向柔度曲率Fd,更易判断损伤。但当损伤发生在沿轴线固定端边界时,轴向柔度曲率Fc本身就有较小突变,应用周向柔度曲率Fd识别防止误判。

Damage Identification of Delaminated Composite Cylinders

In this paper, an NDT method based on modal flexibility curvature matrix was discussed to detect de-
lamination of composite cylinders. The natural frequency and shift values of the composite cylinder are simulated by
modal analysis. The damage of composite cylinder is detected by the calculated axial and circumferential flexibility
curvature matrix. Analysis shows that both axial and circumferential flexibility curvature matrix methods can accurately
identify the location and size of delamination. From the inner wall of the cylinder to the outer wall, the closer the de-
lamination to the outer wall, the more obviously of flexibility curvature mutations, and more easily the delamination to
be detected. And relatively speaking, the mutation of the axial flexibility curvature F c at delaminated location is far
greater than circumferential flexibility curvature F c , so F c is easier to identify delaminations. But due to itself small
mutation at the fixed end boundary, when damage occurs near the fixed end along axis direction, the axial flexibility
curvature F c may cause misjudgment, in this case, the circumferential flexibility curvature F d can be used to identify
damages.