Impact of Wall Configurations on Seismic Fragility of Steel-Sheathed Cold-Formed Steel-Framed Buildings

Liqiang Jiang,Jihong Ye

doi:10.1155/2018/2528549

Abstract

Seismic fragility of steel-sheathed cold-formed steel-framed (CFSF) structures is scarcely investigated; thus, the information for estimation of seismic losses of the steel-sheathed CFSF buildings is insufficient. This study aims to investigate the seismic fragility of steel-sheathed CFSF buildings with different wall configurations. Analytic models for four 2-story steel-sheathed CFSF buildings are established based on shaking table tests on steel-sheathed CFS walls. Then, a group of fragility curves for these buildings are generated. The results show that the thickness of steel sheathing and the fastener spacing of the wall have significant impact on seismic fragility of steel-sheathed CFSF buildings. The seismic fragility of the CFSF building can be reduced by increasing the thickness of steel sheathing or decreasing the fastener spacing. By increasing the thickness of steel sheathing, the reduction on probability is more obvious for the CP limit. It is also found that the exceeding probability is approximately linear with fastener spacing, with a slope in the range from 0.25%/mm to 0.50%/mm.

Highlights

Cold-formed steel (CFS) structure is one of the most popular used building systems for single-family and multi-family residential buildings
Numerical modeling method for steel-sheathed cold-formed steel-framed (CFSF) walls was proposed by Niari et al [19], and this method was verified by the test results. e steel sheathing increased the lateral resistance and ductility of the CFSF structures according to the conclusions drawn by these above references, and this structural system was approved by AISI 400-15 [20]
The impact of wall configurations on seismic fragility is investigated by four 2-story steel-sheathed CFSF buildings

Summary

Introduction

Cold-formed steel (CFS) structure is one of the most popular used building systems for single-family and multi-family residential buildings. Shaking table tests on 10 steel-sheathed CFSF walls and numerical investigations on these specimens were conducted by Rogers and his colleagues [12,13,14]. Shaking table tests of a full-scale CFS building with the discussion of the seismic responses were conducted by Schafer and his colleagues [25, 26]. Shaking table test on a full-scale CFS partition wall infilled steel frame building was performed by Wang et al [27], and fragility curves were generated for these CFS partition walls. Another study aimed to propose the performance limits of CFS partition walls and generated the fragility functions of these walls based on shaking table tests [28]. Very few studies have been conducted to investigate the seismic fragility of steel-sheathed CFSF buildings, especially for the influences on different wall configurations. The effects of sheathing thickness and fastener spacing on seismic fragility of steel-sheathed CFSF buildings were discussed

Representative Steel-Sheathed CFSF Building Structure

Modeling the Steel-Sheathed CFSF Buildings and Test Validation

Displacement

Fragility Analyses of These Steel-Sheathed CFSF Buildings

Findings

Conclusions