Showing 2 results for Farzad
K. Farzad, S. Ghaffari,
Volume 15, Issue 3 (8-2025)
Abstract
The use of steel shear wall systems has increased significantly in recent years as an effective solution for resisting lateral loads in buildings. This study focuses on the seismic collapse safety assessment of steel frames with optimal positions of steel shear walls obtained through various metaheuristic optimization algorithms and concepts of performance-based design methodology. Due to potential irregularities and discontinuities in the lateral load-resisting system and the limitations of code-based linear analysis, nonlinear pushover analyses with multiple lateral load patterns are employed to estimate key structural responses during the optimization process. The seismic collapse performance of the optimized frames is further evaluated using the FEMA P-695 methodology, which involves nonlinear dynamic analysis to assess collapse capacity. The primary objective is to examine the influence of steel plate shear wall placement on the structural weight optimization of steel frames. To this end, two case studies, a 10-story and a 15-story steel frame equipped with steel shear walls, are presented. The results demonstrate the critical role of shear wall location in achieving optimal structural designs.
K. Farzad, M. Javanmard Barbin,
Volume 16, Issue 1 (1-2026)
Abstract
This study investigates the optimal design of steel frames with chevron bracing systems and semi-rigid connections using a performance-based design framework and metaheuristic optimization algorithms. Optimization effectively balances design performance and cost in structural engineering. The three algorithms employed were selected based on their proven application to similar optimization problems, enabling identification of the most suitable approach for the present case. Chevron bracing offers architectural benefits and enhances lateral stiffness and strength. However, unbalanced vertical forces from tension and compression braces under seismic loading require nonlinear analysis for reliable capacity estimation. To address this, pushover analyses with multiple lateral load patterns are performed to capture responses consistent with performance-based design principles. Connection behavior plays a decisive role in the global performance of steel frames. Conventional assumptions of rigid or pinned connections oversimplify reality and produce inaccurate predictions. In this study, semi-rigid connections are modeled with greater fidelity by incorporating column panel zones (CPZs) and gusset plate stiffness at bracing joints. CPZs significantly influence energy dissipation and deformation, while gusset plates may contribute up to 40% of connection rotational stiffness. Neglecting these effects can underestimate interstory drift and misrepresent hinge mechanisms. Results show that accounting for initial connection stiffness improves both accuracy and cost efficiency. For 10- and 15-story frames, structural cost were reduced by about 7%, underscoring the value of realistic connection modeling in optimal design.
