横向线动载荷作用下复合材料层合梁的脱层扩展分析

该文基于可动边界变分原理对层合梁脱层扩展进行了分析,分析中考虑脱层间的接触效应,建立了层合梁在横向线动载荷作用下的非线性控制微分方程及相应的定解条件;同时应用Griffith准则,导出了脱层前缘各点处的能量释放率表达式;算例中讨论了脱层长度、脱层深度、几何尺寸及材料性质等因素对脱层扩展的影响。研究表明:脱层梁承受横向拉力作用时,其发生脱层扩展的可能性要比承受横向压力时大得多;脱层越长、动载荷幅值越大,脱层越容易扩展;脱层越深、梁的长高比L/h及材料的E11/E22比值越大,脱层发生扩展的可能性越小。

ANALYSIS ON DELAMINATION GROWTH OF COMPOSITE LAMINATED BEAMS SUBJECTED TO TRANSVERSE DYNAMIC LOAD

Based on the variational principle of moving boundaries and considering the contact effect between delamination regions,the nonlinear governing equations are derived for delaminated beams subjected to transverse linear dynamic load,and the corresponding boundaries and matching conditions are given in this paper. At the same time,according to the Griffith criterion,the formulas of energy release rate along the delamination front are obtained. In the numerical calculation,the effects of delamination length and depth,the geometrical parameters and the material properties on delamination growth are discussed. It is shown that the delamination growth of laminated beams is more likely to occur under transverse tensions than under transverse compressions. The possibility of delamination growth increases with the increase of the delamination length and the amplitude of dynamic load,and decreases with the increase of the delamination depth,the ratio of L/h and the E11/E22 ratio of the material.