基于弹塑性有限元法的冷挤压模具应变法疲劳寿命分析

摘要

The low-cycle fatigue of a cold extrusion mould was analyzed in this paper. The full strain-time history of the mould in the plastic making process was got by simulation of the plastic making with a coupled thermal-mechanical model. The MSC. Marc post-processing file was modified to filtrate the useless model result data, then the file was re-enveloped. Thus the useful result file was introduced to the professional fatigue analysis software: MSC. Fatigue. The fatigue life was predicted through the strain-life method, and the contour of the mould fatigue life was got. The results make a good agreement with that in the real condition. The result shows this method has a good precision. This method realizes the integrated fatigue life prediction, and provides a whole plan for the mould structure design based on the fatigue life.%对冷挤压模具的低周疲劳破坏进行了寿命分析.首先对模具采用弹塑性热力耦合模型进行了成型过程仿真,获得了成型过程中模具完整的应变-时间历程;然后采用Fortran语言对MSC.Marc分析后处理文件进行修改,删除不需要的模型数据和结果数据,对后处理文件重新进行封装,将需要的弹塑性结果导入到专用疲劳分析软件MSC.Fatigue,使用应变寿命法进行了疲劳寿命预测,获得了模具疲劳寿命分布云图.分析结果与实际情况符合良好,预测寿命具有较高的可信度,实现了挤压模具完整的疲劳寿命预测,为基于疲劳寿命的模具结构设计提供了一整套可行的方法.