Behavior of Residential Safe Room Walls Impacted by Windborne Debris
Tornadoes and hurricanes are among the most devastating storms on the planet. Much of the damage from these storms occurs when debris is picked up by high winds and strikes structures. Safe rooms are often constructed in commercial and residential buildings to protect occupants from windborne debris. The process for designing safe rooms requires all components to pass the large missile test, in which a 2x4 wood missile is fired at high speeds at safe room assemblies. Prescriptive designs may be utilized for residential safe rooms; however, these designs can be costly and difficult to construct. The purpose of this research is to 1) Test safe room wall assemblies constructed with conventional steel sheets and alternative materials in order to decrease the cost and improve constructability of safe rooms, and 2) Develop an experimental procedure to measure full-field deformation of safe room wall assemblies under impact during large missile test. High speed photographs are taken of each impact and digital image correlation technology is used to obtain the deformation of the wall assemblies. Additionally, the stiffness and effective mass are measured for each specimen to verify the results. While the alternative materials tested as part of this research were not successful in resisting debris impact, the non-contact measurements obtained for the passing specimens produced fair results. These measurements are further used to evaluate the behavior of the passing specimens, providing insights that go beyond the qualitative pass/fail method used in previous research.