Study On Nonlinear Dynamic Analysis of Inelastic 3D Frame Buildings under Near-Fault and Far-Fault Ground Motions Using Reduced Modal Techniques

Evaluating the seismic response of intricate three-dimensional (3D) inelastic frames requires sophisticated modelling to account for complex interactions, including bi-axial inelasticity and torsional-translational coupling. Although Nonlinear Dynamic Analysis (NDA) provides the highest precision, its high computational demand for extensive structural systems has led to the development of Reduced Modal Techniques (RMTs). This article offers a detailed synthesis of current RMT developments, such as adaptive Reduced-Order Models (ROMs) and Modal Pushover Analysis (MPA), examining their efficacy under both Far-Fault (FF) and Near-Fault (NF) seismic conditions. The study investigates how these streamlined approaches handle changing dynamic characteristics and the influence of higher modes during non-linear phases. Observations reveal that while RMTs can reduce computational time by over 50%, accurately representing the impulsive force of pulse-like near-fault events still poses significant challenges. By highlighting deficiencies in analysing asymmetric structures and the prospects for integrating artificial intelligence into model reduction, this research establishes a foundation for future advancements in performance-based seismic design.