Use of static tests for predicting damage to cladding panels caused by storm debris

Abstract

The impact by debris can result in extensive damage to building facades and roof coverings in extreme climate conditions such as windstorms and hailstorms. Damage can be in the form of denting on the surface of a metal cladding panel, which is controlled by the amount of force developed at the point of contact between the debris object and the surface of the panel. Amid the lack of guidelines for assessing damage to the building envelope, it is common to conduct impact tests on a cladding specimen. Such tests often involve the use of a gas gun to fire projectiles; however, there are shortcomings with this approach as it is mostly undertaken to check compliance and to observe permanent damage to the specimen. This paper presents the use of quasi-static tests to simulate the impact induced damage to metal cladding in storm scenarios. The contact force value generated during the impact action is predicted using the two-degree-of-freedom system model so that the impact action can be applied in a quasi-static manner on an MTS machine to predict damage in the form of indentation or perforation. This experimental technique for predicting damage is illustrated and verified in this paper by conducting confirmatory impact experiments. The risk of damage to metal cladding caused by impact in storm scenarios could then be assessed with confidence without having to conduct repetitive impact testing involving accelerating projectiles onto specimens of metal cladding. This research provides designers with an accurate and cost effective means of quantifying impact induced damage on building facades, and allows system developers to adapt and utilise existing and new materials to develop innovative solutions for withstanding impact.