Thermal response analysis of aerospace aluminum alloy welded structures

Abstract The aluminum alloy welded structures of spacecraft are inevitably subjected to temperature loads during service. However, there have been few studies on the basic laws of thermal response of aluminum alloy welded structures. Therefore, this paper investigates the basic characteristics of the thermal response through the finite element method. The modeling method of indirect coupling of heat and force of welded joints is studied by using the finite element software Abaqus 6.14 in this research. The temperature fields and the stress fields of plate welded structure under thermal cycling load and cylinder welded structure under thermal shock load are calculated. The characteristics of temperature distribution and stress distribution in welded joints are analyzed. The temperature distribution of the welded joints presents different characteristics on the heating surfaces and the cooling surfaces. The geometry of the joint makes the change of stress field in the joint region different from that in other regions, and the maximum deviation of stress value is greater than 60%. However, the geometry has little effect on the structural deformation, and the deviation of displacement value is less than 0.1%. Mechanical boundary conditions have great influence on the stress of plate welded structure. For different constraints, the maximum deviation of the Mises stress values is 54.4%. Under the action of thermal shock, the change amplitudes of stress field and displacement field near the welded joint of the cylinder gradually decrease with the increase of the diameter. When the diameter is greater than 800 mm, the stress field and displacement field are no longer affected by the curvature of the cylinder. The results of this study reveal the basic laws of the thermal response of welded structures, which is conducive to the advancement of the spatial simulation and application research of aluminum alloy welded structures.