Reliability analysis of cold-formed steel beams susceptible to distortional buckling using numerical analysis data incorporated into the professional factor variable

Resumo

In cold-formed steel (CFS) beams subjected to simple bending with restriction to lateral-torsional
buckling and without restriction on the compressed flange, distortional buckling can be the predominant failure
mode. This work aims to develop a study on the distortional instability mode in CFS lipped C-section subject to
simple bending by numerical analysis using ABAQUS finite element software and CUFSM, a finite strip method
software. The Matlab software was used to automate the modeling so that a range of numerical simulations with
material and geometric nonlinearity was performed and validated with experimental results from the literature. A
reliability analysis with the FORM method was performed using load combinations according to the calibration
parameters of AISI-LRFD and AISI-LSD to obtain the reliability index (β) and probability of failure (PF). From
these results, it was observed a good achievement between the reliability indexes of the models and the established
target index of βo = 2.50, a reference for the calibration of the AISI-LRFD.