A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering in Structural Engineering

Thesis (M. Eng.) - Asian Institute of Technology, 2023

Uncoupled Modal Response History Analysis (UMRHA) is an analysis procedure that can extract the complex nonlinear response of building into individual modes, allowing for accurate estimation of both the global and story-level responses. However, UMRHA is not effective in accurately determining the force demands of components or local member demands. Previous studies attempted to estimate component-level force by assuming that the force distribution pattern on each component remains constant, even when the building experiences high nonlinearity. However, in reality, the force distribution pattern changes, which causes the previous method of UMRHA to produce inaccurate results. To address this issue, a new technique was developed for estimating accurate force demand at the component level. The technique uses data from modal pushover analysis to calibrate the results of UMRHA and obtain more accurate component-level force demand. Here, 34- and 44-story buildings subjected to different types of ground motion are first evaluated using the new technique of UMRHA and compared with Nonlinear Response History Analysis (NLRHA). The results show a significant improvement in accuracy at the component level; the estimated force demands obtained from the proposed UMRHA technique are close to the benchmark values from NLRHA and are superior to the previous UMRHA technique.