Reliability-based numerical modeling of elastoplastic plane trusses

The trusses stand out as a structural system widely applied in engineering solutions. In the field of Structural engineering, several efforts have been done to improve the theoretical and numerical representation of structural systems behavior. The development of computer models enables a robust assessment of the mechanical behavior of structures, both in the design phase and throughout its service life. Considering the nonlinearity observed in the response of most of the structural materials, elastoplastic models arise as a proper choice to the description of the behavior of several ductile materials. Reliability analysis allows the assessment of the structural probability of failure, so that it can be predicted since the design stage. This analysis can be built based on the evaluation of the uncertainties associated with design variables, which are described by random models. This paper addresses a reliability-based analysis applied to finite element models for steel plane trusses in elastoplastic regime, according to an isotropic hardening model. Some uncertainties related to the loads and to geometrical and mechanical properties of the bars are considered, in order to estimate the safety levels associated to ultimate and service limit states, such as cross-section rupture, buckling of bars and inadmissible displacements.