Study On Welding Residual Stress And Hysteretic Behavior Of Steel Plate Shear Wall

With an increasing number of high-rise steel buildings, steel plate shear wall with high lateral stiffness, good ductility, energy dissipation capacity and high safety reservation becomes a novel and effective choice. However, the welding residual stress in steel plate shear wall is prone to brittle fracture and fatigue failure, reduce capacity and overall stability of the structure, and impair seismic performance, leading to serious harm. The main factor affecting the welding residual stress is welding process. Welding residual stresses generated by different welding processes are not the same. Therefore, this paper on research of the welding process and hysteretic behavior of steel plate shear wall has important significance.By investigating the welding sequence, which is the main welding parameter affecting welding residual stress, a reasonable welding sequence is proposed. Through analyzing the effect of residual stress on the hysteretic behavior of steel plate shear walls, a reference for the design and construction is given. The main contents are as follows:(1) Three different kind of SPSW models, which include forms with hole, no hole and diagonal bracing, are built using FEAS-ABAQUS. The temperature and stress fields are acquired by using single ellipsoidal heat source model, which are imported by DFLUX subroutine, to simulate the welding process. it follows that the temperature and stress field under various welding sequence. Welding residual stress got by welding sequence of transverse weld first and then vertical weld is less than that by the other way.(2) After SPSW welding experiment, analysis of stress data shows that in the process of welding, the instantaneous stress and residual stress of each measuring point have significant changes. Different welding sequences make different effects to stress changes and numerical values. Comparison of residual stress values between simulation and measurement are performed and results show that changing rules of simulation and measurement is similar, and agreement of measurement and simulation from SPSW without hole is better than that from SPSW with hole. To ensure the accuracy of residual stress values, a few measures are done during welding process, includes choosing better SPSW, controlling welding process and so forth.(3)The hysteretic performance analysis is performed in different conditions including using different welding sequences and models with and without residual stress. The result shows that hysteretic performance using welding sequences of transverse weld first and then vertical weld is better than the opposite sequence, which is obvious in SPSW without hole. Residual stress will reduce the bearing capacity of structure and make structure into failure stage ahead of time. Residual stress has heavier influence for SPSW without hole than others. The energy dissipation coefficients of the three SPSWs are all close to two and energy dissipation performance of the three are fine.