Innovative resilient steel braced frame with Belleville disk and shape memory alloy assemblies: Fid-Bau Portal

Innovative resilient steel braced frame with Belleville disk and shape memory alloy assemblies

Hadad, Alireza Asgari / Shahrooz, Bahram M. / Fortney, Patrick J.

Highlights • Resilient bracing system based on Belleville disks and Shape memory alloy assemblies. • Derivation of design equations for the resilient bracing system. • Improving structural resiliency by using Nibellen bracing system. • Reducing structural repair cost and time after earthquakes.

Abstract Improving the resiliency of the built environment, particularly against seismic events, has been a crucial matter over the last decade. Changing the structural seismic design strategy and using new structural members has been found to be a solution for achieving a more resilient built environment. In this research the seismic performance of an innovative resilient bracing system based on new structural materials and assemblies using Belleville disks and shape memory alloy was studied. The material models for Belleville disk and shape memory alloy are first verified with the available data, and then the cyclic behavior of the resilient structural assembly built out of Belleville disks and shape memory alloy was studied through finite element analyses. Design equations and procedure were derived and a 5-story building was designed to evaluate the behavior of the resilient system and compare it with a special concentrically braced frame. According to the performed cost analyses, while the cost of structural members would increase by 4% due to the usage of new materials in the resilient system comparing to a special concentrically braced frame, the repair cost was found to decrease 100% at the design base event seismic demand level and 95% at the maximum considered event seismic demand level. Seismic performance of the proposed system was studied through fragility analysis, and the better resiliency of the system could be demonstrated quantitatively based on the available performance assessment tools and mathematical equations.