Reliabilities of Steel Structural Systems Designed by Inelastic Analysis

Several national steel design standards allow, in principle, the use of inelastic system analysis to check the integrity of a steel structural system. However, system reliability considerations have yet to be implemented in any rational way in such design-by-inelastic analysis methods. This paper considers a representative steel moment frame subjected to combined gravity and wind loads. The frame is designed using second-order inelastic analysis with a set of postulated system resistance factors. The probabilities of occurrence of strength and serviceability limit states are evaluated. The effects on these limit state probabilities of system resistance factor and wind-to-gravity load ratio are examined.