Identification of Torsionally Stiff and Flexible Asymmetric Systems, and Their Comparative Seismic Response Evaluation for Low-Rise Frames

Kaatsız K., SUCUOĞLU H.

Journal of Earthquake Engineering, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Publication Date: 2023
  • Doi Number: 10.1080/13632469.2023.2226250
  • Journal Name: Journal of Earthquake Engineering
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Keywords: accidental eccentricity, Asymmetric systems, plan irregularity, torsional status indicators, torsionally flexible, torsionally stiff
  • Middle East Technical University Affiliated: Yes


Torsional status indicators of asymmetrical plan systems are evaluated. The ratio of two modal participation factors in a translational direction (lower to higher mode) is proved as a more accurate indicator than the ratio of translation and rotation dominant modal periods. Seismic responses of low-rise asymmetric-plan frames are then assessed through linear elastic and nonlinear response analysis of representative systems under bi-axial ground motion pairs. The results revealed that those systems that are initially identified as torsionally stiff exhibit a torsionally stiff nonlinear response, whereas those initially categorized as torsionally balanced or flexible evolve to a stiffer torsional performance.