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铸造镁合金不可避免地包含许多微孔洞,这些微孔洞在材料的后续加工及服役过程中将发生演化,并对材料的力学行为产生重要影响.基于球形孔洞体胞模型,提出微孔洞长大及形核方程,它们构成微孔洞的演化方程.根据孔洞演化将造成材料性质弱化的物理机制,将微孔洞演化以弱化函数的形式引入到非经典弹塑性本构方程,得到考虑孔洞演化的铸造镁合金弹塑性本构方程.发展与本构方程相应的有限元数值分析程序,用其模拟了铸造镁合金ML308的微孔洞演化及力学行为,计算结果与实验结果符合较好.
Casting magnesium alloy inevitably contains many micro-voids, which will evolve during the processing and service of the material and have an important effect on the mechanical behavior of the material.According to the spherical cell model, the micro-voids Growth and nucleation equations, which form the evolution equation of micropore.According to the physical mechanism that the pore evolution will cause the material properties to be weakened, the evolution of micropores is introduced into the non-classical elasto-plastic constitutive equation by the weakening function, which is considered Hole evolution of cast magnesium alloy elasto-plastic constitutive equation. Development of finite element numerical analysis program corresponding to the constitutive equation, used to simulate the micro-hole evolution and mechanical behavior of cast magnesium alloy ML308, the calculated results in good agreement with the experimental results .