%0 Journal Article
%T Analysis of Laminated Architectural Glazing Subjected to Wind Load and Windborne Debris Impact
%A Mahesh S. Shetty
%A Lokeswarappa R. Dharani
%A Daniel S. Stutts
%J ISRN Civil Engineering
%D 2012
%R 10.5402/2012/949070
%X During windstorms and hurricanes, architectural glazing is subjected to wind loading and windborne debris impact. Wind-borne debris is categorized into two types. One is small hard missile like roof gravel and the other is large soft missile representing the lumber from wood-framed buildings. Laminated architectural glazing (LAG) is the commonly used glazing in buildings where impact resistance is needed. The prefailure stress response of the LAG due to the combined loading due to wind and windborne debris impact is studied. Following the ASTM standards (E1886 and E1996), a steel ball with an impact velocity of 39.62£¿m/s and a wooden cylinder with an impact velocity 12.19£¿m/s were chosen to be representative of small and large missiles, respectively. A lateral pressure that corresponds to a wind speed of 58.11£¿m/s was used to represent wind loading on LAG. The effect of geometric and material properties on the stress response of a rectangular LAG is studied parametrically. Thinner outer ply would result in better prefailure stress pattern than a thicker outer ply, while thicker interlayer generally results in lower stresses in failure critical areas. The contribution of wind loading to the principal stress is between 5¨C10% of the combined stress with small missile case having higher percentage. 1. Introduction Architectural glazing is highly vulnerable during windstorms, particularly hurricanes, due to wind pressures and associated wind-bone debris. Hurricane Ike in 2008 provided a testament to the damage that can result to the interiors of buildings if the glazing envelope is breached (http:/en.wikipedia.org/wiki/Hurricane_Ike). The typical wind load acting on the glazing during these windstorms can be attributed to turbulent wind, changes in the direction of wind, and also its duration. Typical windborne missile constitutes roof gravel, roof tiles, pieces of lumber, and materials from damaged structures. Beason et al. [1] studied the impact of hurricanes on the glazing damage in the downtown area of Houston, TX, USA. In their observation, the glazing damage was found to be mainly due to windborne roof gravel from building roofs and they recommend using laminated glass for architectural glazing. Laminated glass consists of two soda-lime glass plies held together by an interlayer, which is an adhesive polymer. PVB (polyvinyl butyral) is the commonly used interlayer. According to Beason et al. [1], the outer layer, which is exposed to the wind and debris loads functions as a ¡°sacrificial ply¡± and is allowed to break, whereas the inner layer remains
%U http://www.hindawi.com/journals/isrn.civil.engineering/2012/949070/