Secondary Debris Calculations for Protective Structures

Abstract

There are many computational procedures that can be used to analyze and design protective structures to a blast threat. In practice, the complexity of the analysis and design procedures is dictated by whether the facility to be protected is mandated to meet prescriptive protection requirements, on one hand, or the facility is desired to be designed with consideration to one or more design basis explosive threats. The simplest analysis approaches typically suffice for the former case, while the more complex analysis and design approaches become important for the latter. In either case, however, the primary function of the blast effects calculations is to calculate blast loads from which to design the protective structure. This paper identifies and explores scenarios where secondary debris can affect the response of the protective structures and that can necessitate considering their loading effects when designing them. Examples include the effects of debris from vehicle borne threats and secondary debris generated by an overloaded structure. We describe both simplified and complex physics-based computational approaches that can be used to quantify their loading effects on protective structures, including fast-running simplified models up to complex models employing coupled computational fluid dynamics (CFD) and computational solid dynamics (CSD) approaches. We describe the advantages and limitations associated with each computational approach.