形状记忆合金增强复合材料界面剪应力研究

为研究形状记忆合金长纤维增强复合材料界面剪应力的分布情况,基于单纤维双圆柱拔出模型,推导了脱粘区和粘结区界面剪应力表达式.基于复合材料内部温度分布均匀,马氏体体积分数只与纤维内部轴向应力和温度相关等假设,分别讨论了恒定外应力荷载条件下温度(303、323、343 K)、预应变水平(0％、2％、4％、6％)及固定脱粘长度对界面剪应力分布的影响.数值模拟结果表明,通过控制外界温度和预应变水平,可以改变模型最大界面剪应力的值,进而控制界面脱粘现象的发生.对进一步研究SMA长纤维增强复合材料界面力学行为提供了一定的理论参考.

Study on the interfacial shear stress of a shape memory alloy long-fiber reinforced composite

To research the distributions of interfacial shear stress along the interface between the shape memory alloy(SMA) long-fiber and matrix,the expressions of interfacial shear stress derived in debonded and bonded regions were analyzed by using a single fiber reinforced two-cylinder composite model.Based on the assumptions that the temperature distribution of the composite was uniform and the martensite volume fraction was only related to axial stress and temperature,the influence on the interfacial shear stress was discussed with temperatures of 303K,323K,343K,pre-strain degrees of 0%,2%,4%,6%,and a deboned region under a fixed stress condition.The numerical simulation results indicate that the maximum interfacial shear stress could change with temperatures and pre-strain degrees to avoid the debonding.This study could provide theoretical support and reference for further research on interfacial mechanical properties of fiber reinforced composites.