Lightweight, Blast-Resistant Doors for Retrofit Protection Against the Terrorist Threat

Abstract : Recent research at the Air Force Research Laboratory (AFRL) has addressed the difficult problem of lightweight, blast-resistant doors which can be used in structural retrofits (or new construction) to combat the threat of terrorist bombing. Doors have always been one of the weakest points in most structures, primarily because of the requirement for convenient human access. In some hardened structures, very thick steel doors provide adequate blast protection; but these heavyweight doors are not readily adaptable to more general-purpose, lighter-weight structures, such as businesses and homes. The design problems which must be addressed in creating a lightweight, blast-resistant door can be grouped into three general areas: (1) the door must be lightweight; (2) the door must be capable of withstanding the blast-pressure; and (3) the frame must be capable of holding the blast-resistant door. The first two areas are obvious, but the latter is often overlooked. Stated more specifically, if the "blast-proof" door cannot be contained by the door frame, it will become a large, rigid, and life-threatening projectile. The body of the paper focuses on the specific materials and techniques used to create the AFRL lightweight, blast-resistant doors. These doors use a patent-pending design to resist blast-pressures far above any commercially- available "lightweight" door. In fact, the AFRL blast-resistant doors can achieve protection, with a relatively simple retrofit, that would otherwise require significant and substantial structural modifications. Results from AFRL blast tests on the doors are presented, which clearly show their capability under extremely high blast pressures.