多源异构数据集成下的T形焊接接头疲劳裂纹扩展  

Fatigue crack propagation of T-shaped welded joints under multi-source heterogeneous data integration

作　　者：王小丽 WANG Xiaoli(China General Nuclear Power Corporation,Cgnpc Uranium Resources Co.,Ltd,Beijing 100022,China)

机构地区：[1]中国广核集团中广核铀业发展有限公司,北京100022

出　　处：《焊接技术》2023年第6期24-27,I0005,I0006,共6页Welding Technology

摘　　要：为进一步明确T形焊接接头疲劳断裂机理,在多源异构焊接数据集成基础上以裂纹扩展为分析目标,研究焊接结构抗疲劳性能,给焊接结构抗疲劳设计提供数据支持。将多源异构焊接数据上传至集成中心,把数据优化请求提交给查询优化器,改进焊接数据完整性;通过控制总应变面积得到应力-应变曲线,利用Pairs公式和积分运算分别获得裂纹扩展速率与疲劳寿命;运用热传导方程了解焊接母材温度变化历史曲线,计算裂纹应力强度因子,完成裂纹扩展形态计算。对T形焊接母材与接头焊缝进行疲劳裂纹扩展试验。结果表明:疲劳裂纹扩展方向为从下至上,以穿晶解理模式发生断裂,焊缝部位韧性更优;在应力比分别为0.1,0.3,0.5时,焊缝均具备更好的疲劳裂纹扩展抗力,裂纹开裂前,接头载荷随裂纹张开位移的增加而变大,开裂后接头承载范围慢慢减小,裂纹扩展载荷随之降低。In order to further clarify the fatigue fracture mechanism of T-shaped welded joints,based on the integration of multi-source heterogeneous welding data,the analysis target was crack growth,and the fatigue resistance performance of welded structures was studied to provides data support for fatigue resistance design of welded structures.Upload multi-source heterogeneous welding data to the integration center,submit the data optimization request to the query optimizer,and improve the integrity of welding data.The stress-strain curve was obtained by controlling the total strain area,and the crack growth rate and fatigue life ware obtained by Pairs formula and integral operation respectively.The heat conduction equation was used to understand the temperature change history curve of the welding base metal,calculated the crack stress intensity factor,and complete the calculation of the crack propagation pattern.Conduct fatigue crack propagation tests on the T-shaped welding base material and joint welds.The results showed that the fatigue crack growth direction was from bottom to top,and the fracture occurs in the mode of transgranular cleavage,and the toughness of the weld was better.When the stress ratios were 0.1,0.3,and 0.5,the weld seam had better fatigue crack propagation resistance.Before crack cracking,the joint load increased with the increase of crack opening displacement.After cracking,the bearing range of joints decreased slowly,and the crack growth load decreased accordingly.

关 键 词：多源异构数据 T形焊接接头 疲劳裂纹 裂纹扩展 疲劳寿命 

分 类 号：TG405[金属学及工艺—焊接]