• CN:11-2187/TH
  • ISSN:0577-6686

机械工程学报 ›› 2019, Vol. 55 ›› Issue (18): 70-77.doi: 10.3901/JME.2019.18.070

• 材料科学与工程 • 上一篇    


温玥, 陈章华   

  1. 北京科技大学数理学院 北京 100083
  • 收稿日期:2018-11-05 修回日期:2019-03-27 发布日期:2020-01-07
  • 通讯作者: 陈章华(通信作者),1959年出生,博士,教授,博士研究生导师。主要研究方向为微细观结构的损伤与失效、特殊有限元法等。E-mail:chenzhanghua@ustb.edu.cn
  • 作者简介:温玥,女,1983年出生,博士研究生。主要研究方向为金属材料成形损伤机理及数值模拟。E-mail:yueyuebeike@163.com

Failure Analysis of the Tube Hydroforming Process Based on Anisotropic Damage Coupling Model

WEN Yue, CHEN Zhanghua   

  1. School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083
  • Received:2018-11-05 Revised:2019-03-27 Published:2020-01-07

摘要: 在对金属管材的热态内压成形加工过程中,由于镁合金相对于传统钢材体现出更为复杂的材料特性,使其在生产工艺和数值模拟等方面的研究更具有挑战性,其中破裂失效成为制约其产品质量的重要因素。通过对AZ31B镁合金的热态内压试验和有限元模拟分析,微观结构观察和相关材料常数测定,可以有效地对其材料损伤演化规律及破坏形式进行预测,预判裂纹产生的危险区域及扩展方式。研究表明,从室温过渡到300℃的范围内,AZ31B镁合金管材的成形性能随着温度提高而显著提升。为了避免在塑性成形的过程中出现弯曲起皱现象,并进一步提高成形件的尺寸精度,应该使其初始轴向进给保持在较低的状态,然后使其随着内压的增长而同步提升,并在轴向进给结束后,进一步小幅增加内压并保持。以连续损伤力学为基础,通过建立各向异性损伤的材料模型并与相关试验相互验证,能够有效地描述AZ31B镁合金的力学行为,并对其成形过程中相关的工艺参数提供依据。

关键词: AZ31B镁合金, 热态内压, 各向异性损伤, 有限元分析, 工艺参数

Abstract: Hydroforming of Magnesium tubes presents challenges due to its more complex constitutive behavior. Compared to steel, its low thermoplasticity formability brings more issues in experimental and simulation work. Cracking often limits the quality of product during the hydroforming process. Tube hydrofroming experiments along with the finite element analysis, microstructure and mechanical properties of magnesium alloy AZ31B tube hydroforming are investigated to demonstrate the damage evolution during the process. The dangerous area with high risk of failure is predicted. It is found that formability of magnesium alloy AZ31 can be enhanced with elevated temperature range from room temperature to 300℃. Low initial axial feed and then increased simultaneously with the internal pressure can avoid possible overall buckling and wrinkling. To improve the dimension accuracy of the specimens, internal pressure is further increased when the axial feed is eventually exhausted. Based on continuum damage mechanics, a ductile damage model which takes account of anisotropic behavior of magnesium alloy AZ31B is integrated into an explicit finite element frame work and also be validated with experimental work. Insights are provided for the variation of different process parameters related to formed specimens.

Key words: magnesium alloy AZ31B, hydroforming, anisotropic damage, finite element analysis, process parameter