Elastoplastic nonlinear post-buckling analysis of partially restrained space structures

A method is proposed here to analyze a space structure with large deformation, partially restrained connections, and material nonlinearities using the plastic hinge concept. The assumed stress method is used to derive an explicit form of tangent stiffness satisfying joint equilibrium and displacement compatibility. The unique feature of the method is that it is extremely efficient since the tangent stiffness is expressed in an explicit form and can easily be modified to consider different factors. The method can be used to study both the pre- and post-buckling behavior of space structures. It is verified with experimental and numerical results available in the literature. The robustness of the algorithm is confirmed by applying it to analyze several problems of practical importance. The method is robust yet simple, accurate, and economical.