Lightweight Mitigating Materials for Structures Under Close-In Blast Loading

Abstract

This study investigated the effects of lightweight blast mitigating materials to protect commercial aircraft structures against internal blast loading. Thin clamped aluminum test panels with rivet-attached frame and stringer stiffeners were used to represent a portion of the fuselage structure of a commercial aircraft. These reinforced test panels were prepressurized before blast loading to simulate typical in-flight loads experienced by a commercial aircraft due to cabin pressurization. Bare spherical explosive charges of C4 were then detonated at a fixed distance from the outer surface of these pre-pressurized plates. A high-speed camera was used to determine the mechanism and time scale of failure propagation in the reinforced panels. Eleven unique combinations of blast mitigating linings were used in the testing. The specific explosive charge mass and standoff distance selected for this study was found to produce massive damage in unprotected test panels. Several tests with blast mitigating liners also showed complete destruction of the test panel, indicating the inadequacy of these protective compositions. In the end, it was determined that a blast liner comprised of a rigid outer layer, such as aluminum, in combination with an elastomeric backing layer was successful in preventing the rupture of the reinforced test panel. This material combination was found to be effective over several tests and with slight variations of the specific rigid and flexible materials used.