Investigation of second order effects on moment resisting and concentrically braced steel frame

In this work, second order effects and the suggestions of different country codes about second order effect was investigated under wind and earthquake loads on steel structures. Fort this purpose, different frame system was modelled. First one is moment resisting frame was modelled for sway effect that cause of P- ? effects. Second one is concentrically braced frames was used for the member curvature that cause of P-? effects. The height of frame was constant but the height of storey was changed. First part of this study, the properties of the steel frame systems was given. The codes about second order effects was investigated. Second order analysis methods was researched. The previous studies of this subject is given. Second part of this study, the prepared models was remarked. according to codes increasing load combination and moment magnification factors was used for second order effects under changing of storey height. The result of second order analysis was taken reference values. The calculations of codes suggestions was compared with reference values. Third part of this study, all of this work results was given. The results of comparing about increasing load combinations that LRFD-1999 had the best safety values than the other codes under the changing of storey height. The results of comparing about moment magnification factors that Eurocode-3 and BS-2000 had the best safety values than the the other codes .