ELASTIC-PLASTIC ANALYSIS OF ORTHOTROPIC MULTILAYERED BEAM

Elastic-plastic deformation of a beam, composed of layers with materia l orthotropic in elastic and plastic domains, is analyzed in this pape r. The first material direction of each layer is inclined at an angle (+alpha and -alpha successively) with respect to the beam axis. The yi eld condition represents a generalization of the Hill's criterion to i nclude the material hardening. The derived incremental relations for s tress calculation are based on the governing parameter method (GPM), d eveloped by the first author, where the problem of implicit integratio n of inelastic constitutive relations is reduced to solution of one go verning nonlinear equation. The expressions for tangent elastic-plasti c moduli are also given. One solved numerical example demonstrates the main characteristics of the developed algorithm, suitable for a gener al elastic-plastic analysis of composite beams.