摘要
基于Voronoi算法对铝合金焊接接头进行细观组织建模,构建三维等轴晶、柱状晶区结合区域的多晶模型。结合接头初始晶粒取向,并将其赋予到多晶模型中。运用晶体塑性理论,编写用户自定义材料子程序,对焊态下及经腐蚀后的接头在拉伸状态下的细观应力分布进行数值模拟研究。结果表明:在拉伸形变的过程中,接头细观最大应力出现在柱状晶区、等轴晶结合区域,并且随着腐蚀的平均深度和表面损伤度增加,蚀坑边缘产生应力突变,其应力峰值变大,容易成为裂纹起裂的源头。
Based on Voronoi algorithm,a three- dimensional mesoscopic structure model of aluminum alloy welded joint was built,which consists of the polycrystalline regions of equiaxial and columnar grains. According to the determined initial grain orientation data,orientations were assigned to the polycrystalline model. Using crystal plasticity theory,a user-defined material subroutine was developed to study the mesoscopic stress distribution of both as-welded and corroded joints. Results show that the maximum stress appears at the binding region of columnar and equiaxial grains. With the development of average depth and surface damage of corrosion,the stress distribution fluctuates along the edge of corrosion pits,and the peak stress increases,leading to the initiation of cracks.
出处
《兵器材料科学与工程》
CAS
CSCD
北大核心
2016年第5期53-57,共5页
Ordnance Material Science and Engineering
基金
国家自然科学基金项目(51105049)
关键词
铝合金焊接接头
腐蚀
多晶模型
晶体塑性有限元
细观应力
aluminum alloy welded joints
corrosion
polycrystalline model
crystal plasticity finite element method
meso stress
