Open-Source Implementation of a Method for Post-Collapse Frame Analysis
DOI:
https://doi.org/10.70567/mc.v42.ocsid8246Keywords:
Computational Elastoplasticity, ultimate load, post-collapse, softening hingesAbstract
One of the causes of structural collapse is creep failure in critical sections. The classic analysis of the ultimate load considers that once the plastic limit is reached in a section, the strength at the hinge remains constant while plastic deformation develops in other sections. It can be shown that this method overestimates the collapse load. As an alternative to this approach, the strength failure response can be considered, by considering softening hinges that are formed upon reaching limit values. In this work, a numerical method is described in detail to apply the Euler-Bernoulli finite element with strong rotation discontinuity to the modeling of plastic softening hinges in beams and planar frames, using displacements control. The described formulation was implemented as open-source extending the software ONSAS (www.onsas.org). Numerical examples from the literature are solved, and the obtained results validate the implementation and show the potential of its application.
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