Nonlinear buckling and postbuckling of cable-stiffened prestressed domes

Nonlinear buckling phenomenon of a novel type of structure, namely, a prest ressed dome, is investigated using a nonlinear finite-element model. A pres tressed dome is formed by buckling its individual flat members into arch fr ame works, and then the structure may be stiffened by cable loops in the ci rcumferential direction. A corotational formulation of a 3D beam element, a nd a cable element, which is modeled as a catenary between connected points in the dome, are used to develop an algorithm for nonlinear stability anal ysis of the system by considering large displacements and rotational. The i ncremental load technique using a Newton-Raphson iteration scheme in conjun ction with Crisfield's modified are-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 sho w that skeletal domes with stiffeners buckle at much higher loads than the corresponding unstiffened domes.