Fragility Modeling of Urban Building Envelopes Subjected to Windborne Debris Hazards.

Nonstructural damage to the cladding and façades systems caused by excessive wind pressure and debris impact is the primary damage to urban high/midrise buildings after hurricanes. This paper focuses on the assessment of damage to urban buildings envelopes due to windborne debris while leaving the wind pressure-induced damage outside the scope. The existing building envelope damage assessment models for urban high/mid-rise buildings often neglect the geometry of building clusters or simply assume a homogeneous configuration, which can introduce errors and uncertainties for urban building clusters with varying geometries and layouts. In this context, this paper proposes a new fragility modeling approach for urban buildings envelopes, which explicitly considers geometric configurations of urban buildings, to improve the accuracy of risk assessment for urban buildings. To develop such a fragility model, first, a physical model of debris impact on building envelopes is established, considering the configuration of the surrounding buildings. Then the fragility function is rigorously formulated by propagating the uncertainties from hurricane wind hazard, local urban wind field, the resistance of the envelope component, as well as debris size, location and generation. Reduced-order modeling and Monte Carlo simulation are employed to construct fragility surfaces. An illustrative example is presented to validate the proposed physical model of debris impact and demonstrate the implementation of the proposed fragility modeling approach. [ABSTRACT FROM AUTHOR]