关键词: 比例柔度矩阵, 复合材料, 脱层损伤, 损伤检测

Abstract: The LU decomposition of the proportional flexibility matrix is used to construct a new damage index, which is used to detect the delamination damage of composite beams. Firstly, the finite element software ANSYS Workbench is used to construct the simulation models of damaged beam and undamaged beam. The natural frequency and mode shape of the undamaged beam and the damaged beam are obtained by modal analysis. The normalized vibration mode of the unit matrix is calculated, and then the proportional flexibility matrix is constructed. Through LU decomposition of the difference matrix of proportional flexibility before and after damage, a new damage index is constructed to detect the delamination damage of composite beams. The simulation results show that the mutation rate of the damage index has great changes for different degrees of single point and multi-point damage. For different locations of damage, it also has a good recognition effect, and can accurately describe the area of delamination damage. This method shows that the proportional flexibility matrix method can be used to identify the delamination damage of composite beams.

Key words: proportional flexibility matrix, composites, delamination damage, damage detect