Steel frames which are commonly used in multi-storey and industrial buildings, bridges and offshore structures may exhibit significantly nonlinear behavior prior to achieving their ultimate capacity. Thus, a second-order inelastic analysis or advanced analysis is the most rational mean for assessment of the performance of a whole structural system instead of using conventional analysis approach. This book presents an efficient numerical procedure for advanced analysis of three-dimensional steel frames under static and dynamic loadings. The formulations of catenary, truss and refined plastic hinge elements are presented for modeling inelastic behavior of cable, truss and beam-column members, respectively. The generalized displacement control method is adopted for tracing post-buckling equilibrium paths of structures exhibiting the snap-back and snap-through phenomena, whereas an incremental-iterative solution scheme based on Newmark and Newton-Raphson methods is employed for capturing time-history responses of structures under dynamic loadings.