Elementos finitos para a análise limite de cascas axissimétricas via programação não-linear

Abstract

This work is concerned with rigid-plastic limit analysis of shells of revolution subject to rotationally symmetric loadings. These shells, of arbitrary shape, are discretized into a series of finite elements, each being a conical shell. The von Mises condition, valid for sandwich shells, is used. After assembling the finite elements, the limit analysis program is reduced to a simple application of the non-linear programming technique where the sequential unconstrained minimization technique (SUMT), the generalized reduced gradient method and the tolerance flexible method are utilized for statically admissible and kinematically admissible approaches. Therefore, upper bounds and lower bounds of the collapse loads are found for some problems: conical, spherical, ellipsoidal, torispherical shells etc. These numerical results are illustrated and compared with existing ones described in the literature and others provided from elastic-plastic analysis.