Improved steel frame performance against progressive collapse with infill panels.

Local failure of one or more components due to abnormal loading can induce progressive collapse of a building structure. Herein, improved structural robustness is targeted to improve steel frame performance against progressive collapse. A multi-scale analysis model is constructed; then, the anti-collapse performance of a plane steel frame structure with a flush end plate connection is comprehensively analyzed using nonlinear static analysis. To enhance the anti-collapse capability of the steel frame structure, reasonable addition of infill panels in indirect- and direct-influence areas is proposed. Infill panels properly arranged in direct influence area can give full play to the Vierendeel mechanism, and effectively improve combined ability of the remaining structure. And then 1/8–1/6 of the net span is recommended as the length of the infill steel panel for the steel frame structure with flush end plate connection. • The performance of a plane steel frame structure to progressive collapse is investigated. • A structure with a flush end plate connection is considered. • The nonlinear static analysis method and a multi-scale analysis method are used. • Addition of infill panels to the direct- and indirect-influence areas is examined. • Reasonable addition of infill panels improves the resistance ability of the structure. [ABSTRACT FROM AUTHOR]