【摘要】 船舶一般为大型焊接结构，焊接接头处较易产生裂纹等缺陷，因此需开展焊接接头裂纹萌生及扩展研究。首先，基于双线性内聚力模型对不锈钢钎焊接头模型进行裂纹萌生及扩展的数值模拟计算，获得载荷与裂纹扩展长度的关系，并与文献试验结果进行对比分析。在两者结果较为一致的基础上，采用相同方法对船舶典型焊接接头的裂纹萌生及扩展进行数值模拟计算和分析。结果表明，基于双线性内聚力模型的裂纹萌生及扩展分析方法能够较好地模拟船舶焊接接头裂纹扩展过程中的开裂、损伤积累及损伤未积累阶段。焊接接头裂纹萌生及扩展研究可为后续进行相关船舶结构安全评定奠定理论研究基础。更多还原

【Abstract】 Ships are generally large welded structures. Cracks and other defects are easy to occur at the joint. Therefore,the crack initiation and propagation methods of welded joints need to be studied. Firstly, based on the bilinear cohesive zone model, the crack initiation and propagation of brazed stainless steel joints are numerically simulated, the relationship between load and crack propagation length is obtained and compared with the experimental results in literature, and on the basis of the two results are more consistent, the same method is adopted then the crack initiation and propagation of typical welded joints of ships is numerically simulated and analyzed. The results show that the crack initiation and propagation analysis method based on the bilinear cohesion model can better simulate the cracking, damage accumulation and damage non-accumulation stages in the crack propagation process of welded joints of ships. Through the numerical study of crack initiation and propagation of welded joints, the theoretical basis for the subsequent ship structural safety assessment is established.更多还原