Structural reliability analysis of steel plane frames with semi-rigid connections

Abstract

The design codes for structural design traditionally establish the adoption of partial safety factors to deal with uncertainties. These standards do not allow one to know the real probabilities of failure of a structure. What is needed, from a practical and scientific point of view, is a more consistent approach, based on reliability theory. This article addresses an initial attempt at determining the safety levels of structures based on advanced analysis and design with structural reliability theory. In this context, the authors consider the effects of the geometric nonlinearity and flexibility of connections in the reliability analysis, which aims at setting a certain displacement as the service limit state. For this purpose, a computer program was written called Structural Reliability Module. This program uses a First Order Reliability Method to analyse reliability. To carry out the structural analysis of steel structures, this study uses the program Computational System for Advanced Structural Analysis. Validating the Structural Reliability Module involved comparing the results from other authors with those generated by the program. Results for the structures under study indicate the efficiency of the implemented measures. Results suggest that, when a certain displacement is set as a service limit state, the reliability of the structures under analysis are only slightly influenced by geometric nonlinearity but considerably so by semi-rigid connections.

Análise da Capacidade Resistente e da Rigidez de Ligações Tubulares Tipo K com Banzos Circular e Retangular

“…Observa-se na Tabela 6 que os índices de confiabilidade relacionados aos estados limites de serviço diminuíram a medida que a rigidez das ligações foi sendo reduzida, o que era esperado, uma vez que a presença das ligações semirrígidas reduziu a rigidez global do pórtico analisado. Este resultado foi também encontrado por Agostini et al (2018).…”

Improvements of Rackwitz–Fiessler Method for Correlated Structural Reliability Analysis

“…In China, the design code "unified standard for reliability design of engineering structures (GB50153-2008)" [2008] also adopts RF method to deal with uncorrelated non-Normal variables. However, when it comes to the correlated non-Normal reliability problems, NATAF is always the first recommendation in most references [Agostini et al (2018); Duprat et al (2010); Fu et al (2017); Huang et al (2018); Jiang et al (2015a); Karadeniz (2013); Noh et al (2009); Tung (1999)]. This may be because Der Kiureghian and Liu [1986] have developed a reasonable theoretical formula for NATAF to estimate the correlation coefficients of transformed Normal variables, i.e., Eq.…”

Instabilidade elástica por força cortante em terças de aço formadas a frio com alma enrijecida

“…O momento fletor máximo solicitante para a viga acaba sendo deslocado da seção d para a seção c no caso das ligações com comportamento igual ao da Curva 2 ou igual ao comportamento da Curva 3. vez que a presença das ligações semirrígidas reduziu a rigidez global do pórtico analisado. Este resultado foi também encontrado porAgostini et al (2018).…”