基于微观损伤模型的强度非均质焊接接头抗延性裂纹扩展阻力特性研究

INVESTIGATION ON RESISTANCE PROPERTY TO STABLE CRACK GROWTH FOR NON-HOMOGENEOUS WELDED JOINT BASED ON MICRO-DAMAGE MODEL

基于材料微观损伤模型，采用三维有限元数值方法，定量研究了焊接接头中强度匹配、试件几何型式对接头抗延性裂纹扩展阻力特性的影响。首先由标准三点弯曲试件的阻力曲线，得出反映材料微观损伤的特殊单元模型控制参量，再根据该参量对不同接头强度匹配下双边缺口拉伸试件的阻力曲线进行了定量预测，其结果与试验结果相当吻合。表明特殊单元模型能很好地描述材料的抗延性裂纹扩展阻力特性。

The effects of strength mis-matching and specimen geometry on the resistance to ductile crack growth for welded joint were conducted by 3-D FE analysis based on the micro-damage model. Firstly, the parameters controlling ductile crack growth are gotten from the resistance curve result of standard 3 point bending specimen, then the resistance curves of the tension specimen for the welded joint with different strength mis-matching are predicted hased on the cell mds. It is found that the result predicted is in a good agree ment with the experiment, and the cell mds gives a good description of ductile crack growth.