• CN:11-2187/TH
  • ISSN:0577-6686

›› 1987, Vol. 23 ›› Issue (4): 43-50.

• 论文 • 上一篇    下一篇

J 积分在非均质焊接接头弹塑性断裂研究中的应用

马维甸;张式程;田锡唐   

  1. 清华大学 哈尔滨工业大学
  • 发布日期:1987-09-01

APPLICATION OF THE J-INTEGRAL TO ELASTO PLASTIC FRACTURE STUDY OF NON-HOMOGENEOUS WELDED JOINTS

Ma Weidian;Zhang Shicheng;Tian Xifang   

  1. Tsinghua University Harbin Institute of Technology
  • Published:1987-09-01

摘要: 应用弹塑性有限元法分析了J积分方法用于非均质焊接接头安全性评价的两个疑难问题:证实了J积分对于用来模拟一些典型的焊接接头的、裂纹平行于界面的软夹硬不均匀体仍然路径无关,而且J积分的能量率表达式仍危害适用。本文还对这种不均质条件下J积分的路径无关性进行了数学证明。探明了软夹硬不均匀体力学性能不均匀性对J积分值的影响规律:硬夹层两侧软区的屈服倾向于使J积分值增高;由于软区的屈服程度因硬夹层相对宽度h/2a而异,h/2a越小,相同载荷作用下的J积分值越大。

Abstract: The path-independence property of the J-integral for a non-homogeneous panel with a sandwiched hard layer containing a centre crack parallel to the interfaces, which is a simplified model of some typical welded joints and the validity of are investigated by means of elasto-plastic FEM with the view of applying the J-integral method to the safety assment of welded joints with mechanial non-homogeneity. It is shown that the J-integral remains path-independent and the expression of the J-integral as the rate of decrease of indent of potential energy, is still applicable in spite, of the non-homogeneity. The path independence of J in such a non-homogeneous environment is also confirmed mathematically. The effect of the mechanical non-homogeneity upon the J-integral values is studied. It is concluded that the yielding of the two soft zones between which the. Hard layer is sandwiched tends to make the J values increase; the smaller the relative hard layer width; h/2 a , the larger is the J value at the same load because the degree of yielding of the soft zones varies from h/2a to h/2a.