A triangular finite element for sequential limit analysis of shells
The numerical solution of the limit analysis problem has experienced a growing interest in recent years. Methods developed in this context can be employed also to obtain indications on the structural response subsequent to collapse, which is required in several situations, such as for shells employed as shock absorbers or energy dissipators. The procedure is known as sequential limit analysis and, as its name suggests, is based on a sequence of limit analysis solutions referring to progressively updated configurations. In this paper, the limit analysis procedure proposed by Capsoni and Corradi [Int. J. Numer. Meth. Eng. 40 (1997) 2063] is employed to this purpose in conjunction with the TRIC shell element developed by Argyris and co-workers [Comp. Meth. Appl. Mech. Eng. 145 (1997) 11], which is modified to some extent to adapt to the rigidplastic context. Some examples show the effectiveness and the accuracy of the method, which compares well with results obtained from complete, although computationally demanding, incremental elasticplastic approaches.
sequential limit analysis shells post-collapse behavior plates shell finite elements