Seismic Performance of an Innovative Light-Frame Cold-Formed Steel Frame for Midrise Construction

Abstract

This paper presents the method and results of a study whose objective was to investigate the seismic performance of a new light-frame cold-formed steel-frame system. The system includes floor trusses, open panels, V-braced panels, columns, and connections. To do this, a series of reversed-cyclic tests were conducted on subassemblies. The results of this experimental program provided insight into the behavior of the subassemblies under cyclic loading, which in turn provided key information for numerical modeling of the subassemblies and the whole system as well as failure mechanisms of the frame. Nonlinear time history analyses were performed using a new formulation for a 4-story frame using a suite of earthquake ground motions to demonstrate the behavior of a typical V-braced system in a moderate earthquake. Both test results and numerical analysis indicate that the system has good ductility as a result of the screwed plate connections between the light-gauge members and between the light-gauge members and square columns. The frame system performed very well at four stories making it a viable midrise construction option in seismic regions of the United States and around the world.