Effect of Random Initial Crookedness of Members on Reliability of Steel Frames

The effect of two types of common initial geometric imperfections on the reliability of steel frames was investigated. These imperfections are the coordinates of connection nodes and crookedness of members. Most of the finite element reliability analyses in the past haveneglect this source of uncertainty. For this purpose, static non-linear pushover structural analysis was used in the present work from which reliabilities were estimated based on the FORM and Monte Carlo sampling methods. Furthermore, to investigate the importance of uncertain parameters, reliability sensitivity analysis was performed by the use of direct differentiation method, which was implemented in the object oriented framework of OpenSees software. It was demonstrated that some of these geometric imperfections have significant influence on the reliability assessment of steel frames.