The Experimental Research And Finite Element Analysis On The Welding Residual Stresses Of The Box-sections Beyond Limits Of Width-thickness Ratio

Welding is one of the most important connections in steel structure. Welding of steel is used to reduce the thickness of structural to optimize methods to reduce the steel consumption. In order to ensure the security and reliability of welded structure, improving economic efficiency, residual stresses distribution must be recognized accurately of the welding box beam which is beyond the limits of width-thickness ratio.This paper analysis the welding residual stress through testing methods in laboratory and FEM numerical simulation to ten welded box-sections which is beyond the limits of width-thickness ratio , described the welding residual stress of the testing methods integrally and analysis the basic theory of the welding temperature field and stress field, Finally, applies the FEM analysis software ANSYS to establish the welding box beam finite element model based on the generating mechanism of welding residual stress analysis, and simulates the three-dimensional temperature field and stress field of the box welding beam by its heat-structure of the coupling function.The numerical simulation results prove the practicality and effectiveness of the numerical simulation of welding.In this paper, research achievements are as follows:(1) To use the blind-hole method to measure the residual stress of the box welding beam by laboratory, and obtains the welding residual stress distribution through data analysis. The tensile stresses distribute in the weld and the surrounding region, the tensile stresses gradually transformed into pressure with increasing distance, the residual stress decrease at the same time as the thickness of steel as well as the yield strength of steel increases. (2) To achieve numerical simulation of welding process through the APDL language. To consider the material nonlinearity, namely the temperature change on the impact of material properties. To obtains the temperature distribution at different time by method of killing activating elements of welding heat source model.Based on the laboratory measurements for the welding process, this paper has obtained the welding deformation and residual stress distribution, provides an effective method of reference to design reasonally.