论文部分内容阅读
实际构件中大量存在着半穿透型的焊接表面裂纹 ,对于这种力学性能不均匀三维裂纹体的弹塑性断裂力学参量 (例如J积分 )的探讨还比较缺乏。利用J积分直接测试方法以及适当的理论弹性修正 ,对存在于不同组配比的高组配焊接接头焊缝区的三维表面裂纹的J积分进行了试验研究 ,着重讨论了接头组配比对焊接接头试样加载过程中裂纹扩展驱动力 (J积分 ,裂纹嘴张开位移CMOD)、应变沿积分路径分布的影响。结果表明 ,焊接接头试样上应变的分布趋势取决于裂纹位置和组配比的综合影响 ;随载荷的增加 ,邻近焊缝的母材区将产生应变集中 ;并且 ,随组配比的降低 ,该区域的应变集中程度随之提高 ,而焊缝区的变形量随之降低 ,裂纹扩展驱动力增大。
There are a lot of semi-penetrating welding surface cracks in the actual members, and there is a lack of discussion on the elastic-plastic fracture mechanics parameters (such as J-integral) of this three-dimensional cracked body with non-uniform mechanical properties. By using J integral direct test method and proper theoretical elastic correction, the J-integral of three-dimensional surface crack existing in the weld zone of the high-assembly welded joint with different compounding ratio was tested and studied. The influence of the driving force of crack propagation (J integral, CMOD of cracked mouth opening) and the distribution of the strain path along the integral path during the loading process of the specimen. The results show that the trend of strain distribution on the welded joint depends on the combined effect of crack location and composition ratio. With the increase of load, the strain concentration will occur in the base metal region adjacent to the weld. With the decrease of mixture ratio, The degree of strain concentration in the area increases, while the deformation of the weld zone decreases and the driving force of crack propagation increases.