Analysis Of Welding Residual Stress Of K-type Outrigger Truss

With the rapid development of China's economy,science and technology,super high-rise buildings have gradually increased in recent years,and the building height has been continuously refreshed.As a common form of super high-rise building,the frame-and-tube structure will also bring about the defects of insufficient lateral stiffness and large internal force of the core cylinder with the increase of height.For this purpose,the outrigger truss with high flexural and shear stiffness is usually used to increase the capsizing resistance of the structure.During the truss connection process,the extra-thick plate welding will generate large residual stress,and at the same time,due to the uneven settlement of the frame tube structure,certain stress will be generated in the truss.In order to reduce the additional stress generated in the construction process of outrigger truss,ensure its working performance,and provide theoretical reference for the rational design of construction scheme,this paper makes an in-depth study on the welding residual stress of outrigger truss and its mechanical properties under the combined action of welding and uneven settlement.The main research contents are as follows:1.Simulation method and verification of outrigger truss weldingBased on the traditional welding simulation method,this paper uses ANSYS software to carry out refined solid modeling of outrigger truss,adopts the uneven mesh division method,and uses the segmented moving instantaneous body heat source as the simplified heat source model to load,and then merges the weld bead.The method and the post-weld cooling time are determined to greatly improve the calculation efficiency of the giant component welding simulation.The feasibility of the simulation method is verified by comparing the simulation results with the measured results.A simplified simulation method for outrigger truss welding is proposed.2.the influence of welding on residual stress of outrigger trussAccording to the more common factors affecting the welding residual stress in the construction,the welding process of the welding sequence,the interface form and the welding duration are analyzed.The results show that different welding methods have a great influence on the weld of the flange plate,and the residual stress changes by more than 40%.Therefore,the reasonable welding process can effectively reduce the residual stress in the component.By studying the influence of different welding processes on the residual stress,the theoretical reference for the development of the welding process of outrigger truss is provided.3.Stress analysis of outrigger truss under the combined action of welding and settlementAccording to the engineering example,the stress distribution law of outrigger truss under the joint action of welding and settlement is studied.The non-uniform settlement value of the frame-tube structure under each connection scheme is simulated,and the additional stress under the joint action of welding and settlement under different construction schemes is compared and analyzed taking into account the delayed connection technology adopted in construction.The influence mechanism of the connection timing and temporary connection on the additional internal force of outrigger truss is clarified,and relevant guidance suggestions are given for the connection scheme of outrigger truss in the actual project.