A co-rotational model for elastoplastic analysis of planar frames

Resumo

A co-rotational model is employed to analyze planar frames considering plasticity effects lumped at
plastic hinges. The element is locally formulated as the traditional linear element based on the Euler-Bernoulli
theory. The hinges effects are introduced into the generalized strain fields as Dirac deltas centered at the element
ends, which naturally results in the formulation of the element with plastic hinges. The plastic constrained
nonlinear system of equation of the local problems is solved with the Newton-Raphson method running through
all plastic possibilities, whereas a classical force-control procedure solves the global nonlinear equilibrium
equations. Two examples are presented to demonstrate the robustness of the formulation to deal with geometrical
nonlinear elastoplastic analysis of frames.