Experimental Cyclic Performance of Viscoelastic Gypsum Connections and Shear Walls

Abstract

The shear capacity of gypsum sheathed shear walls is typically neglected in areas of high seismicity due to the susceptibility of conventional drywall screw connections to damage caused by earthquakes. This paper presents an alternative to the conventional screwed sheathing connection found in wood-framed gypsum shear walls. A viscoelastic (VE) polymer was inserted between the sheathing and the stud framing. A sheathing connection study and shear wall study were performed, and the results of the VE connection show a dramatic increase in stiffness and energy dissipation over the conventional screwed connection. Energy dissipation increases 632% for the sheathing connection and 510% for the shear wall. Stiffness of the shear wall also improves. The VE polymer improves structural performance while resisting damage when subjected to shear displacements up to 18 mm by providing a constant source of energy dissipation. This new VE sheathing connection may allow for weak or nonstructural materials, such as gypsum wallboard, to be used as structural elements for design purposes while reducing the risk of costly damages during seismic events.