Experimental Evaluation of the In-Plane Seismic Behavior of Storefront Window Systems

Abstract

Storefront window systems have been shown to suffer significant damage during earthquake loading, resulting in the potential for human injuries and significant economic losses. Despite the potential for film-coated windows to minimize seismic-induced damage to window systems, limited study has been undertaken. Furthermore, no thorough study of the effects of loading histories on window system performance has been performed to-date. Finally, previous studies have been limited in terms of their variation of window system geometry. In this work, three variables of interest were studied through in-plane seismic racking experiments of storefront window systems, namely: (i) loading protocol, (ii) window film type and attachment, and (iii) aspect ratio. This paper presents the overall experimental program, the identified damage modes and associated drift limits, and trends associated with variation of the window film and aspect ratio. A companion paper in this issue (Hutchinson et. al. 2011) summarizes studies of the effects of load protocol.

Development of a Drift Protocol for Seismic Performance Evaluation considering a Damage Index Concept

“…A series of in-plane seismic racking experiments were conducted on a unidirectional shake table to quantify the damage modes and associated drift limits of window systems. The test matrix, experimental set-up, and test results for other variables considered in the program may be found in a companion paper (Eva and Hutchinson 2011). In this section, results are summarized as related to the study of load protocol effects.…”

“…Effects of load protocol on (a) serviceability damage states and (b) ultimate damage states. (refer to Eva and Hutchinson 2011, for physical description of damage states).…”

“…The final adopted protocol shown in Figure 1f includes modifications by Brueggeman et al (2000), which limit the frequency ranges to 0.4 and 0.8 Hz. It should be noted that the crescendo test is similar in configuration to the multiple step test described in ATC (1992), with the (Eva and Hutchinson 2011).…”

“…Example of hysteretic response of window systems (Eva and Hutchinson 2011). …”