纯镁旋锻变形过程的有限元模拟

FINITE-ELEMENT MODELING OF DEFORMATION PROCESS OF PURE MAGNESIUM DURING ROTARY SWAGING

利用非线性有限元分析软件MSC／Marc及热-机耦合弹塑性模型模拟了纯镁旋锻变形过程,得到了应力和应变及温度场的分布及变化情况,并且导出了防止两种旋锻缺陷产生的条件．结果表明,变形区可分为工件头部、已成形区、压缩区三个部分．已成形区中应变沿径向分布不均匀,中心部位变形量还不及边缘部位的1／2．防止发生锻不透和边缘裂纹两种缺陷的条件分别为: εc≥ε0,εe<εb．模拟所得螺旋形脊椎纹缺陷平均高度为0．0037 mm,与实测结果误差为7．5％．由变形不均引起的残余应力在18—30 MPa间,变形温升效应不显著．

By using finite-element software program, MSC/Marc, and coupled thermomechanical model the rotary swaging process of pure magnesium was simulated. Distributions and changes of stress, strain and temperature are clarified and the critical conditions predicting two deformation defects are obtained. The deformation zone can be divided into the bulging head-end, the formed zone and the reduction zone. In the formed zone, the equivalent strain distributes inhomogeneously along the radial direction. The equivalent strain in the center is about half of that at the edge. The critical conditions of preventing insufficient forging and edge-cracking are εc 〉 ε0, εe 〈 εb, respectively. The simulated height of spiral spine-like ridge is 0.0037 mm and the error is 7.5%. The residual stresses are between 18 MPa and 30 MPa. Temperature-rising owing to the heat translation from plastic deformation energy is not notable.