Effects of Finish Materials and Dynamic Loading on the Cyclic Response of Woodframe Shearwalls

Abstract

A study on the effects of gypsum wallboard and stucco nonstructural finish materials on the seismic capacity of woodframe shearwalls was carried out. The focus was on the performance of shearwalls with these finish materials combined with a wood structural sheathing (plywood or oriented strand board). Also investigated were the effects of dynamic loading with rates on the order of a woodframe structural response to a seismic event. All testing was performed using standard construction 2.4 m square woodframe shearwalls loaded at the top plate. Findings from the study indicate that nonstructural finish materials have a substantial influence on the performance of woodframe shearwalls, causing increases in strength and stiffness, and reductions in deformation capacity. There was also a noticeable change in failure mode created by the application of finish materials. The loading rate study, comparing specimens under quasi-static loading with specimens loaded dynamically, showed only modest differences caused by dynamic loading. Small increases in strength and stiffness were observed in some specimens; however, in general, the effect was negligible.