部分界面脱黏时颗粒增强金属基复合材料的弹塑性性能

Elastoplastic Behavior of Particle Reinforced Metal Matrix Composites Considering Partially Interfacial Debonding

基于Eshelby等效夹杂理论和Mori-Tanaka平均场理论,导出含损伤两相复合材料的刚度张量.认为颗粒增强金属基复合材料的界面脱黏受控于颗粒所受的拉应力,引入Weibull分布函数描述颗粒脱黏概率,且受单向拉伸载荷作用时,仅在沿受力方向的上下两侧发生部分界面脱黏,从而将部分脱黏的各向同性颗粒由一完好的横观各向同性颗粒来等效,建立了部分脱黏模型.假定基体为各向同性材料,颗粒仅产生弹性变形,基体产生弹塑性变形且满足Mises屈服准则和等向强化准则,采用割线模量法讨论了球形颗粒增强金属基复合材料部分界面脱黏时的弹塑性性能,理论预测与实验结果吻合较好.

Based on Mori-Tanaka＇s concept of average stress in the matrix and Eshelby＇s equivalent inclusions theory, the rigid tensor is derived considering the damaged phase under the prescribed traction boundary conditions. Weibull distribution function is used to characterize phenomenologically the debonded probability of the interface, which is decided by the tensile stress of the particle. A partially debonded isotropic spherical elastic particle is replaced by an equivalent, perfectly bonded spherical particle, which possesses yet unknown transversely isotropic elastic moduli. The fictitious particles can be determined in such a way that their tensile and shear stresses will only vanish in the debonded direction. The matrix and composite are postulated isotropic and the matrix satisfies Mises yield criterion and isotropic hardening law. Then the elastoplastic properties of the spherical particle reinforced metal matrix are discussed considering the interfacial debonding by secant modulus method. The theoretical uniaxial stressstrain bebavior of the composite agrees well with the experimental curves.