Lower bound limit analysis through discontinuous finite elements and semi-analytical procedures

Abstract. This work deals with the limit analysis of structures through lower-bound theorem, using dislocations based finite elements and eigenstress modelling. The lower bound approach is on knowledge self-equilibrated stresses that constitutes basis domain where optimal solution should be searched. A twofold strategy can used to get stresses, i.e., eigenstresses. first one pursues calculation stress numerical approximation differential equilibrium equation in homogeneous form an a posteriori discretization polynomial representation degree. second consists Finite Element implementation by discontinuous Volterra's theory. Both formulations are written terms strain precisely nodal displacement parameters. Consequently, it possible formulate iterative procedure starting from dislocation at incoming collapse, Melan’s residual sense, calculate structural ductility requirement. Several examples presented confirm method's feasibility.