ASSESSMENT OF THE RELIABILITY OF COLD-FORMED STEEL MEMBERS SUBJECTED TO BENDING AND COMPRESSION USING THE FORM METHOD

Resumo

The structural reliability consists to the analysis of the probability of limit state violation for
a structural system during the useful life. This paper presents an analysis of reliability indexes for cold
formed members subjected to bending and to the axial compression force, designed according to the
Brazilian standard ABNT NBR 14762:2010 [1] and the North American standard AISI S100:2016 [2].
For this purpose, a database of experimental results of several authors was elaborated for the limit
states in question and the strengths were obtained for each model tested, using ABNT NBR
14762:2010 [1]. The model errors, relation between the theoretical and the experimental values, were
also evaluated, providing a statistical result, also called the professional coefficient. Then, it was
obtained the reliability index (β) as a function of the resistance factor (γ) based on the First Order
Reliability Method - FORM. The resistance factors were obtained to combinations of gravitational
loads of the North American and Brazilian standards, beyond the relations between the live and dead
loads, Ln/Dn, equals to 3 and 5. The results were compared to the target reliability index (β0) usually
employed in calibration of the main international standards and to the recommended values by
Brazilian and North American standards, considering the similarity between both specifications for the
limit states studied.