摘要
针对三点弯曲裂纹试样,利用弹塑性损伤-应变耦合的有限元方法,研究了在不同强度匹配焊接接头中,母材区断裂应变的变化对焊缝区裂纹断裂力学参量J积分的影响规律.研究结果表明,在焊接接头中,材料损伤的出现将使裂纹扩展驱动力J积分增加,即裂纹更易扩展.对于高、等和低匹配的焊接接头,在焊缝区各项力学性能参数保持不变的条件下,随着母材区断裂应变的减小,焊缝区的塑性应变及裂纹扩展驱动力J积分均有明显的提高,使结构的安全性下降.随着接头强度匹配比的降低(母材屈服强度的升高),母材区断裂应变的变化对J积分的影响作用逐渐减弱.
The fully coupled strain and damage elasto-plastic finite element method is adopted and a three-point bend model is selected to analyze the influence of the rupture strain of base metal on J-integral in cracked weldments with different strength matching ratio. The simulated results show that the presence of damage in welded joint may get rise in the value of J-integral, thus the cracks have the stronger tendency to extend. When the other mechanical parameters remain constant, with the decrease of the base metal rupture strain, both the plastic strain in weld metal and J-integral increase for all types of welded joint with different strength matching ratio. With the decrease of strength matching ratio of welded joints, viz. the increase of the base metal strength, the effect of the base metal rupture strain on J-integral weakens gradually.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2003年第9期937-940,共4页
Journal of Xi'an Jiaotong University
基金
教育部骨干教师基金资助项目 .
关键词
焊接接头
损伤
有限元
J积分
Cracks
Finite element method
Fracture mechanics
Numerical methods
Stress analysis
