Vehicular Access Doors under Hurricane Force Wind Pressure: Analysis Methods and a Design Tool

It is essential that rolling sheet metal access doors in metal buildings, and the door jambs they are attached to, resist high pressures during an extreme wind event. Catastrophic damage to the building and its contents can occur if the door fails, as documented by recent post!hurricane surveys conducted after Hurricanes Ike and Katrina (FEMA 2005a; FEMA 2005b; RICOWI 2006; RICOWI 2007; RICOWI 2009). Once the door is breached, pressure accumulates inside the building that can fail the walls and roof (Figure 1). Estimated yearly damage from windinduced damage in the U.S. is 5.4 billion dollars (NOAA 2011), reinforcing the need for reliable wind resistance structures and accurate wind design procedures.

This research program aims to complement the existing DASMA access door wind analysis approach with a general procedure applicable to a wider range of access doors and jamb details, including doors attached to flexible jambs, e.g., cold-formed steel framing. The generalized analysis procedures are founded on an analytical framework of nonlinear Euler-Bernoulli elastica differential equations. Jamb stiffness boundary conditions are approximated with hand calculations employing existing cantilever and torsional stiffness engineering expressions. The analytical framework is validated with thin-shell finite element modeling and the Douglasville experimental data, and then implemented as a custom built, freely available Matlab program.