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

Domestic houses built of cold-formed steel (CFS) are typically supported laterally by wall panels that are made of braced steel studs. The behaviour 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 paper presents seismic performance behaviour 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, totalling 60 records, were employed for the non-linear time-history analyses of single-degree-of-freedom models the hysteretic behaviour 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. Whilst 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 were used at all.