Nonlinear Buckling and Postbuckling of Cable-Stiffened Prestressed Domes

Nonlinear buckling phenomenon of a novel type of structure, namely, a prestressed dome, is investigated using a nonlinear finite-element model. A prestressed dome is formed by buckling its individual flat members into arch frame works, and then the structure may be stiffened by cable loops in the circumferential direction. A corotational formulation of a 3D beam element, and a cable element, which is modeled as a catenary between connected points in the dome, are used to develop an algorithm for nonlinear stability analysis of the system by considering large displacements and rotations. The incremental load technique using a Newton-Raphson iteration scheme in conjunction with Crisfield's modified arc-length method is utilized to trace the nonlinear path of equilibrium. Buckling of prestressed domes with different numbers and locations of cable stiffeners are studied, and the results show that skeletal domes with stiffeners buckle at much higher loads than the corresponding unstiffened domes.