Nonlinear Behavior and Design of Mid- to High-Rise Diagrid Structures in Seismic Regions

The aesthetics and structural advantages of the diagrid structural system have made it an attractive choice for many buildings across the world, including several notable high-rise building structures built in recent years. This paper presents an investigation of nonlinear behavior and design of mid- to high-rise steel diagrid structures. Weight, story drift, fundamental period, lateral stiffness, and sequence of plastic hinge formation in steel diagrids are studied and compared with corresponding moment-resisting frames and concentrically braced frames. To improve the nonlinear behavior and increase the collapse load capacity of diagrid structures in high seismic regions, practical design guidelines are proposed by using virtual work/energy diagrams and by performing nonlinear static analysis. So far, the diagrid system has been used mostly in the design of tall buildings in the range of 20 to 100 stories. A conclusion of this research is that the diagrid system can also be an efficient and economical structural system for mid-rise buildings in the 8- to 15-story range.