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本文通过数值模拟分析了梯度微结构对金属玻璃(Metallic glass,MG)拉伸性能的影响。将自由体积理论以UMAT子程序形式导入ABAQUS中,模拟分析MG基体中剪切带的演化。在此模型中,颗粒和初始自由体积被以各种梯度方程的形式分布于MG基体中,对材料模型施加单轴拉伸荷载。结果表明含有颗粒按凹槽状梯度分布的MG基复合材料拉伸塑性最好,并且变形中呈现颈缩现象;对于初始自由体积呈凸形分布的MG塑性被很好改善;当改变自由体积梯度分布程度时,梯度越小,则塑性提高越明显;而就颗粒来说,两侧密集区层数越多,变形中就不会出现穿透试样的主剪切带。
In this paper, the effect of gradient microstructure on the tensile properties of metallic glass (MG) was analyzed by numerical simulation. The theory of free volume was introduced into ABAQUS as a UMAT subroutine to simulate the evolution of shear bands in MG matrix. In this model, the particles and the initial free volume are distributed in the MG matrix in the form of various gradient equations to uniaxially tension the material model. The results show that MG matrix composites containing particles distributed by groove gradient have the best tensile plasticity and neck shrinkage during deformation. The MG plasticity with convex distribution of initial free volume is well improved. When the free volume gradient Distribution, the smaller the gradient, the more obvious plastic increase; and particles, the more dense layers on both sides, the deformation will not appear through the specimen of the main shear zone.