大型钢结构厚板对接焊接变形试验研究

Experimental Research on Butt-Welding Deformation of Thick Plates in Large Steel Structure

针对国内外现有预测钢板对接焊接变形的经验公式不适用于大型钢结构厚板的现状,结合南京长江第三大桥钢塔的制造,开展厚板足尺模型对接焊接变形试验研究。结果表明:为了减小焊接变形,必须对厚板对接坡口尺寸进行优化,并采用合理的焊接顺序,对于非对称X形坡口,宜先焊大坡口侧,后焊小坡口侧,对于不同板厚应合理预设反变形;结构自重对焊接变形影响较大;厚板对接焊接的横向变形随板厚的增加而线性增大;纵向变形与焊缝面积成正比,且随着板厚增加而减小;角变形随板厚的增加呈指数趋势减小。依据试验结果,给出厚板对接焊接横向、纵向变形和角变形的预测经验公式。

In reference to the current status that the existing experience formulae at home and abroad to predict butt-welding deformation of steel plates were inapplicable to the thick plates in large steel structure, the butt-welding deformation tests with full-scale thick plate models were conducted during the fabrication process of the steel towers of Nanjing No. 3 Yangtze River Bridge. The results indicate that the groove dimensions must be optimized and the rational welding sequence must be adopted, namely, the large groove side should be welded at first for the non-symmetrical X-type groove, and the proper angular distortion must be pre-setup according to different plate thickness for decreasing the welding deformation influenced by the deadweight of steel plates. For the butt-welding of thick plates, the transverse deformation will increase linearly and the longitudinal deformation which is proportional to the weld area will decrease and the angular distortion will decrease exponentially with the increase of steel plate thickness. The experience formulae to predict the transverse deformation and the longitudinal deformation and the angular distortion of thick plates butt-welding are induced through the test results.