为了更好地研究镁合金轧制过程的织构演变,对商用有限元软件ABAQUS/Explicit的用户材料接口VUMAT做二次开发,实现晶体塑性力学和有限元方法的耦合。对于单个晶粒,通过相关模型计算每个增量步的塑性应变增量,Voce硬化模型计算应变硬化。由于变形机制的不同,分别计算滑移和孪晶引起的晶格旋转。采用弹塑性自洽模型计算单晶体和多晶体之间的联系。应用编制的程序,分别模拟AZ31板材和AZ31铸件的轧制过程。结果表明,该程序能够较好地预测轧制过程的织构演化。
To gain a better understanding about texture evolution during rolling process of AZ31 alloy, polycrystalline plasticity model was implemented into the explicit FE package, ABAQUS/Explicit by writing a user subroutine VUMAT. For each individual grain in the polycrystalline aggregate, the rate dependent model was adopted to calculate the plastic shear strain increment in combination with the Voce hardening law to describe the hardening response, the lattice reorientation caused by slip and twinning were calculated separately due to their different mechanisms. The elasto-plastic self consistent (EPSC) model was employed to relate the response of individual grain to the response of the polycrystalline aggregate. Rolling processes of AZ31 sheet and as-cast AZ31 alloy were simulated respectively. The predicted texture distributions are in aualitative a~reement with experimental results.