Seismic Performance Behavior of Cold-Formed Steel Wall Panels by Quasi-static Tests and Incremental Dynamic Analyses

Abstract

Domestic houses built of cold-formed steel (CFS) are typically supported laterally by wall panels that are made of braced steel studs. The behavior of those panels under cyclic strain reversals in an earthquake is too complex to analyse and is best evaluated by physical experimentation. Dynamic testings of full-scale wall specimens on a shaker table have been undertaken in previous studies but repeating those tests for different design configurations and base excitations can be very costly. This article presents seismic performance behavior of CFS wall panels based on monotonic, and cyclic, quasi-static tests followed by incremental dynamic analyses (IDA). Five accelerogram ensembles comprising artificial, and recorded, accelerograms, totaling 60 records, were employed for the nonlinear time-history analyses of single-degree-of-freedom models the hysteretic behavior of which had been calibrated to match with test results. Although IDA as a procedure has been around for a long time it has always been difficult to achieve reliable, and representative, correlations between Intensity and Damage to the structure given the sensitivity of the correlations to what ground motion record was used. While peak ground acceleration (PGA) and response spectral acceleration (SA) are popular choices of Intensity Measures (IM) the use of peak ground velocity (PGV) and peak spectral demand parameters such as peak displacement demand (PDD) are considered to be preferred choices for certain structural systems depending on their natural period of vibration. Given that suitable IMs have been used the outcomes of the IDA were little affected by whether the accelerograms were artificial, or recorded, or whether filtering was used at all.