低匹配对接接头的“等承载”设计及拉伸疲劳行为  

Design of Undermatching Butt Joints for Equal Load-carrying Capacity and Tensile and Fatigue Behaviors of Joints

作　　者：赵智力[1] 方洪渊[1] 杨建国[1] 胡继超[1] 

机构地区：[1]哈尔滨工业大学现代焊接生产技术国家重点实验室,哈尔滨150001

出　　处：《机械工程学报》2010年第10期75-80,共6页Journal of Mechanical Engineering

摘　　要：为提高高强钢低匹配接头的承载能力,以'等承载能力'(Equal load-carryingc apacity,ELCC)(即焊缝与母材承载能力相等)为原则,进行对接接头的形状参数设计。有限元计算表明,ELCC设计使对接接头焊缝区域(包括焊趾和焊根)应力应变显著降低,低强焊缝的承载能力提高。试验结果表明,ELCC对接接头强度可基本达到母材抗拉强度;在高应力区,ELCC对接接头疲劳强度与削平等匹配接头非常接近,在低应力区,随匹配比降低ELCC对接接头疲劳寿命有所降低;0.57屈服强度匹配比的ELCC对接接头对应1×107循环的疲劳强度较焊态等匹配对接接头提高约115%,可达到0.96匹配比削平对接接头的80%。ELCC设计克服低匹配接头承载能力低的不足,并且可在较大范围内选择匹配比而不必降低应用应力。To improve the load-carrying capacity of undermatching joints of high strength steel,the shape parameters of butt joints are designed on the principle of ＂equal load-carrying capacity＂（ELCC）,i.e.weld and base metal have equal load-carrying capacity.Finite element analysis results indicate that this design makes the stress and strain of weld zone including weld toe and weld root of undermatching butt joints decrease significantly,so the load-carrying capacity of low strength weld is improved.Experimental results show that the strength of ELCC butt joints basically reaches the tensile strength of base metal.In the high stress region,the fatigue strength of ELCC butt joints is very close to that of equalmatching flush joints.In the low stress region,the fatigue strength slightly decreases with the decreasing of mis-match ratio.Compared with as-welded equalmatching butt joint,the fatigue strength of ELCC butt joint（yield strength match ratio is 0.57） corresponding to 1×107 cycles increases about 115%,and reaches 80% of the 0.96 undermatching flush joints.The shortcoming of lower carrying capacity of undermatching joints can be avoided by ELCC design,and the match ratio can be selected in larger range without reducing the applied stress.

关 键 词：低匹配对接接头 等承载能力 形状参数设计 拉伸和疲劳行为 

分 类 号：TG404[金属学及工艺—焊接]