采用有限元法分析了在残余应力和外加横向载荷作用下纤维体积分数对SiC/Ti-6Al-4V复合材料横向拉伸行为的影响。通过弹簧连接纤维与基体界面的重合节点来模拟界面脱粘。结果表明,在界面结合强度一定时,界面脱粘应力(对应于应力-应变曲线上应变的跳跃)受0°方向界面径向残余应力影响较大;在界面脱粘先于基体屈服时,复合材料失效应力(对应于应力-应变曲线上的水平部分)主要取决于纤维体积分数,且体积分数越低,失效应力越高。
The transverse tensile properties of SiC/Ti-6Al-4V composites, subjected to both residual stress and applied transverse stress, have been investigated with emphasis on effects of fiber volume fractions by finite element analysis. Coincident nodes at fiber/matrix interfaces were connected by springs to simulate interfacial debonding. The results indicate that the applied stresses required to cause interfacial debonding (corresponding to strain jumps in stress-strain curves) are mainly affected by interfacial residual radial stresses at θ=0° under fixed interfacial bonding strength. The collapse stresses (corresponding to horizontal parts in stress-strain curves) of the composites, however, are a function of fiber volume fractions. Furthermore, the lower the fiber volume fractions are, the higher the collapse stresses are.