正交各向异性弹塑性材料拉伸颈缩的数值模拟

On Finite Orthotropic Elastic-Plastic Necking Deformation of a Round Bar

介绍了在乘法分解的基础上对正交各向异性弹塑材料进行有限变形计算的一种有限元方法 ,利用该方法考虑不同各向异性状态对正交各向异性材料圆棒试样的拉伸大应变颈缩过程进行了数值模拟。结果表明 :( 1 )材料塑性性质若在不同取向有明显差异 ,沿不同材料轴向拉伸反映的材料力学性能会有非常大的差别。这种差别在载荷和不同方向的径向颈缩位移上远较在颈部截面面积变化上明显 ;( 2 ) Hill的正交各向异性塑性理论并没有考虑晶体材料在各个与材料主轴平面有较大夹角的滑移面上容易发生剪切变形 ,所以不一定适于晶体塑性材料。同时本文研究进一步证实了作者建议的正交各向异性弹塑性有限变形计算方法的合理性。

The major aim of this paper is the research of finite deformation of orthotropic elastic-plasticity for a round bar under tension. Meanwhile, on the basis of multiplicative decomposition concept, a finite element method suitable to calculating the finite orthotropic elastic-plastic deformation has been suggested. The simulated results of the orthortropic finite plastic deformation of a bar made of orthortropic plastic material under large strain tension show the shape of the necking section of the bar is elliptic, and there are very evident differences in mechanical behavior and in defferent directional necking deformation when the tension is in different orientation.