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Recent events involving the impact of large transport aircraft such as the Boeing 767 and 757 into the World Trade Center Towers and the Pentagon have revealed the vulnerability of such structures to terrorist attack. Incidents involving smaller general aviation aircraft have shown the damage that this class of plane can do beyond a protected perimeter. These incidents have elicited inquiries with regard to the effects of impacts of these aircraft types into other critical facilities including aboveground and below ground storage facilities, nuclear power plants, damns and other military and civilian installations. A significant capability to evaluate these threats has been developed during the past 10 years. Small medium and large aircraft have been impacted into buried and aboveground reinforced concrete and light steel frame storage facilities. Both explicit aircraft models and Riera functions (a simplified aircraft impact loading function) have been used to generate an extensive data base. The effects of engines impacting have been studied separately as penetrators. Illustrated in this paper is validation of computational tools for impacts into structures and the initial development of a generalized evaluation tool for rapid evaluation of threats and consequence of aircraft impact into protected facilities.

Ship impact is an important loading scenario for analysis and design of bridges, oil platforms, and other marine structures. Ships collision is also a very important design consideration for ship hulls. Designing structures to resist both accidental and intentional ship impact requires characterization of the impact loading history. Standard design practice relies on simplified methods to determine the impact loads, which typically consider only speed and mass of the vessel. However, ship impact is a complicated non-linear structural dynamic event that depends not just on the size and mass of the vessel, but also local stiffening pattern, location and function of the bulkheads, possible ice-strengthening classification, draft, presence of the bulbous bow, and many other factors. Neglecting these factors can lead to overestimation or underestimation of the loads, depending on a specific scenario. The discrepancies between simplified load estimates and detailed finite element analyses are investigated in this paper.Copyright © 2015 by ASME

We present an overview of the analysis and design of mitigation schemes for buried structures subjected to impact loading, with a focus on the hazard evaluation to underground utilities from the demolition by implosion of the Veterans Memorial Coliseum in New Haven, CT. We discuss the analytical and numerical investigations validated by field testing conducted prior to the implosion and leading to the design of the mitigation schemes aimed at protecting the utilities buried under ground. All the designed and constructed mitigation schemes proved successful during the January 2007 implosion of the Veterans Memorial Coliseum.