Research On Welding Technology And Stability Of Thick Spherical Cap Structure

In this paper, the thick spherical cap structure is used to solve some problems about the welding technology and stability of this structure.1. For the small-scale structure of spherical cap, the structural stress and deformation during the welding process is numerically simulated with a welding program, which is developed based on large FEM software ANSYS using the heat-elastic-plastic finite element method. Based on this, 3D FEM numerical simulation of the welding process of this small-scale spherical cap is presented, moreover, the law of deformation variety and residual stress variety is obtained when welding is used in this small-scale structure. It also provides reliable foundation for welding technology of the spherical cap structure.2. Based on the heat-elastic-plastic finite element method, an inherent strain elastic-plastic finite element method is applied to predicting welding deformation of large-scale structure of thick spherical cap. The welding technology is analyzed by this method and the welding deformation at different cases is received. The most optimum welding technology is also found out through comparison analysis of various welding technology in numerical analysis.3. The structural stress and deformation during the welding process are numerically simulated with a welding program, which is developed based on the large FEM software ABAQUS. Based on validating the legitimacy of this welding program, 3D FEM numerical simulation of the welding process on the spherical cap structure is presented. And the law of welding deformation varying with the thickness of spherical cap structure, welding groove shape and welding sequence is obtained, providing reliable foundation for controlling the structural welding deformation.4. The stability of a concave spherical watertight cabin under the pumping load when still lying at the slipway is carried out. The stability of the spherical watertight cabin with different shell thickness and various stiffeners is discussed. On the basis of the stability analysis of the reinforcement of the spherical cabin, Optimization research of the cabin is further studied. Considering machining technical requirements of the spherical cabin, a rational design of the spherical structure is obtained. The research has much value to the design of submarine's bulkhead.