Performance-Based Seismic Design and Evaluation of Fused Steel Diagrid Frame

Abstract

A fused steel diagrid frame (FSDF) is an innovative earthquake resilient structural system. FSDF combines the steel diagrid structural system with shear links (SLs) and moment connections (MCs) to dissipate earthquake energy. SLs are placed between diamond-shaped grid units and serve as the primary seismic force-resisting system (SFRS). MCs provide the additional resistance as the secondary SFRS. To facilitate the design of the proposed FSDF system, a performance-based equivalent energy design procedure (EEDP) is utilized to design a prototype building. EEDP allows designers to select multiple performance objectives under different earthquake hazard intensities. A detailed finite element model is developed to simulate the nonlinear dynamic response of the structure under earthquake shaking intensities. The results of nonlinear dynamic analyses show that the FSDF has superior seismic performance and can be efficiently designed using EEDP. Lastly, detailed collapse risk assessment of the prototype building utilizing the FSDF is conducted using the Federal Emergency Management Agency FEMA P695 (2009) methodology. The result shows that the EEDP-designed FSDF has superior margin against collapse.