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基于自由体积理论建立了以自由体积为内部参量的非晶合金本构模型,并通过ABAQUS UMAT子程序将之在有限元模拟中实现.以初始自由体积为材料缺陷参量,通过FORTRAN子程序抽取随机数及匹配单元编号的方法定义了初始随机材料缺陷.采用平面应变模型模拟了具有初始随机材料缺陷的非晶合金剪切带的形成和扩展过程,结果表明:自由体积局部增加会造成形变局部化,继而形成剪切带,并且剪切带的成核、形成和扩展会松弛周围应变和自由体积.数值模拟能有效捕捉非晶合金剪切带主要特征,其结果符合实验观察和自由体积理论预测.
Based on the free volume theory, a constitutive model of amorphous alloy with free volume as its internal parameter was established and realized by ABAQUS UMAT subroutine in finite element simulation. The initial free volume was taken as the material defect parameter and the random code was extracted by FORTRAN subroutine Number and matching unit number are used to define the initial random material defects.The plane strain model is used to simulate the formation and propagation of amorphous alloy shear bands with initial random material defects.The results show that the local increase of free volume leads to the localized deformation , And then form a shear band, and the shear band nucleation, formation and expansion will relax the surrounding strain and free volume.Numerical simulation can effectively capture the main features of the amorphous alloy shear band, the results in line with experimental observations and free volume theory prediction .