Analytical Energy Release Rate of Interfacial Crack in Composite Laminates

复合材料层合板界面裂纹能量释放率解析方法研究

School of Power and Energy, Northwestern Polytechnical University, Xi’an 710072, China

Received: 22 January 2018

Abstract

In order to study whether the interfacial crack will grow or not in the composite laminates, the energy release rate of a crack in three-point bending model was obtained by using the Timoshenko beam theory and local generalized forces. The results of energy release rate were validated by the finite element results. The results indicate that the energy release rate of left crack tip is equal to that of the right crack tip when the crack before the crack goes cross the loading point; after the crack goes cross the loading point, the energy release rate of the left crack tip increases and then decreases gradually, while the energy release rate of right crack tip decreases first and increases later; the energy release rate of left crack tip is equal to that of the right crack tip again when the crack is symmetric with the loading point.

摘要

为了研究界面裂纹在复合材料中是否扩展，使用Timoshenko梁理论和局部广义力得到了三点弯曲模型中裂纹两端的解析能量释放率。研究结果和有限元结果进行对比验证，发现解析解和有限元结果相吻合。结果表明：裂纹在载荷点一侧时，左端和右端的能量释放率相等；当穿过载荷点以后，裂纹左端的能量释放率继续上升后逐渐下降，裂纹右端的能量释放率则下降后上升；当裂纹关于载荷点对称时，两端能量释放率相等。