Experimental Research And Analysis Of Welding Residual Stress Of The Tensile Anchorage Region

Welding connection occupies an increasingly important position in the steel structure by a series of advantages, and has now became a key component of equipments and structures such as steel bridge, long-span structures, turbines, boilers, pressure reactor shell. Modern Welding is developing in order to meet the increasingly strong demand of large-scale structure and various complex forms of thick plate welding with high parameters, but there is no thoroughgoing understanding of welding residual distribution of different welding processes, forms and the region. Therefore the analysis of residual stress on the mechanical properties of components can not be accurate. This paper focuses on this issue, and analyses and studies welding residual stress of thick plates in complex circumstances based on Chongqing Guanyinyan Bridge Anchorage region.First, the heat transfer of the welding process is analyzed in theory by separation of submerged arc welding in heat transfer process. Second, though the three basic method of heat transfer: heat conduction, heat convective transfer, radiative heat transfer, welding temperature field is analyzed; mathematical descriptions, boundary conditions and numerical solutions is introduced. And then, welding residual stress and the change of metallographic microstructure are analyzed based on the analysis of welding temperature field.In order to research the distribution of welding residual stress of anchorage area of tensile anchor plates, three full-scale representative models of joint in the tensile anchor plate and cable-beam of Guanyinyan Bridge were made. The results of the test shows that there are different degrees of welding residual stress in main welding lines and some are close to yield strength. Though furthermore researching and analyzing the distribution character and influential factors of welding residual stress of anchorage area, corresponding opinions and suggestions are put forward as well. The study also provides us a lot of reliable reference data for decreasing and avoiding welding residual stress in design and manufacture of similar structure.