摘要
根据重庆市江津观音岩长江大桥各梁段和锚拉板的施工制作工艺,以足尺比例制作3个索梁锚固区域锚拉板与工字型截面主梁的连接试件,进行超声波冲击消除钢结构桥梁焊接残余应力的试验研究。结果表明:焊接后,各焊缝存在着相当大的焊接残余应力,很多焊缝平行焊缝长度方向的焊接残余应力在300 MPa(拉应力)以上。实施超声波冲击后,熔透角焊缝X方向的焊接残余应力平均下降50%以上,Y方向平均下降60%以上;丁字型接头焊缝X方向的焊接应力平均下降89.7%,Y方向平均下降96.5%;有些测点的焊接残余应力从拉应力变为压应力。可见,超声波冲击可大幅度削减焊缝的焊接残余应力的峰值(尤其是对高焊接残余应力的焊缝),并能使焊接应力的分布更趋合理化,明显改善锚拉板区域的受力状态,有利于提高焊缝的疲劳强度。
According to the construction and fabrication process of the beam and anchor plate of Guanyinyan Yangtze River Bridge in Chongqing, three full-scale ratio models of anchorage area and H-beam connection were made to be tested. The purpose of the test was to research on the elimination of welding residual stress in steel structure bridge by ultrasonic peening method. The results showed that there were considerable welding residual stress after welding and many of the residual stress parallel to the welding length were more than 300 MPa （tensile stress）. After implementing the ultrasonic peening, the residual stress of filled welds in X direction fell averagely more than 50% and Y direction fell averagely more than 60%. The residual stress in X direction of the T joint decreased 89.7% and Y direction decreased 96.5%. Some of the welding residual stresses even changed from the tensile stress into compressive stress. It is obvious that ultrasonic peening can substantially reduce the welding residual stress peak. Especially for high residual stress in the welding, and can make the distribution of welding stress more reasonable. Therefore the state of stress in tensile anchor plate area can be remarkably improved, which can improve the fatigue strength of weld.
出处
《中国铁道科学》
EI
CAS
CSCD
北大核心
2008年第5期46-50,共5页
China Railway Science
关键词
钢结构桥梁
锚固区域
焊缝
焊接残余应力
超声波冲击
Steel structure bridge
Anchorage area
Weld
Welding residual stress
Ultrasonic peening
