模型复合材料弹塑性界面应力分析

Stress Analysis of Elastic Plastic Interphase for Model Compostites

由纤维增强弹塑性基体所产生的界面具有弹塑性力学行为。考虑到一般材料的塑性变形都遵循幂硬化规律,对模型复合材料的界面进行弹性和应变硬化状态下的变形规律及其应力分析。以纤维拨出试验为研究模型,将界面分成弹性区和塑性区。利用界面应力剪滞理论,分别建立弹性区和塑性区的界面力学基本方程。选择适当的位移函数满足基本方程及埋入纤维的边界条件,再按位移函数求出弹性区和塑性区的界面剪应力。推导出平均界面剪应力与纤维埋入长度之间的关系式。

The interphase generated by the fibre reinforcing elastic plastic matrix is possessed of elastic plastic mechanical behaviour. Considering the plastic deformation of general material to abide by the power law hardening, the paper conducts analyses of deformation and stress for the interphase of model composites under elastic and plastic hardening conditions. Take the fibre pull out test for studying model, and divide the interface into elastic zone and plastic zone. By employing the shear lag theory, the basic equations of interfacial mechanics for the elastic zone and the plastic zone are established respectively. Displacement functions selected reasonably must meet the basic equations and the end condition of the fibre. And by the functions the interfacial shear stresses in elastic and plastic zones are solved. The relatioship between mean interfacial shear stress and the fibre length in the matrix is deduced. The problem of elastic plastic interface failure is discussed at last.