Seismic performance evaluation of space-frame structures using nonlinear static and time-history analyses

Space-frame structures are extensively used in modern architecture and engineering due to their high load-bearing efficiency, lightweight nature, and suitability for large-span applications. This study assesses their seismic response through nonlinear static and time-history analyses using finite element modeling in ABAQUS. Various configurations with different spans, heights, and column arrangements were analyzed under seismic loads. The response modification factor (R) was evaluated concerning ductility-based reduction, overstrength, and allowable stress factors, ranging from 2.6 to 3.8. Results indicate that structural ductility plays a crucial role in determining the Response modification factor, with notable variations across different configurations. Increasing the number of columns improves this factor, whereas low-story models exhibit reduced ductile behavior. Time-history analysis reveals that base shear values remain within a similar range but are sensitive to frequency content. Additionally, increasing the story height leads to a significant rise in maximum roof displacement, highlighting the influence of height on seismic performance and structural stability in dynamic conditions.