SBIR-STTR Award

Novel lightweight, energy-absorbing, composite, modular solutions to be used for the next generation of Earth Covered Magazines (ECMs) are proposed. These solutions will enable construction and maintenance efficiencies while still achieving the same level of protection afforded by existing ECMs. As part of the proposed Phase I effort, Karagozian & Case, Inc. (K&C) and our collaborators A-P-T Research, Inc. (APT) and Dr. Theodor Krauthammer will investigate the feasibility of incorporating metallic foams, standardized cold-formed steel framing, and mass timber into the next generation ECMs. A cost-benefit analysis will be conducted in conjunction with the Government at the outset to allocate and apportion these materials into cost effective and efficient candidate composite panel concepts for further Phase I investigation. Following this analysis, a select number of dynamic material characterization tests will be performed to inform high-fidelity physics-based modeling aimed at assessing the relative performance of candidate concepts to various levels of blast loading and their ultimate limit states. In the event the Phase I option is exercised, three prototype ECM concepts incorporating candidate composite panels (e.g., Figure 1) will be developed with a focus on panel connections, lateral stability, field installation, facility operations, and moisture infiltration considerations for further investigation during Phase II.

Benefit:
Once fully developed and incorporated into ECMs, the candidate composite panel concepts will allow for better blast performance when compared to existing ECM designs and facilitate ECM maintenance. The intent is that the new ECMs will be comparable in cost, if not more cost effective once the design is fully streamlined, to current ECM designs. This improved blast performance will allow for more ordnance to be stored than presently on a land square foot basis. Additionally, maintenance issues associated with maintaining a minimum of two feet of earth cover will be able to be relaxed, which should assist in future O&M budgets.

Keywords:
CFS, CFS, ECM, CLT, magazine, Modular, metallic foam, Lightweight

A novel, lightweight, energy-absorbing, durable, modular, and strong earth covered magazine (ECM) (i.e., the Lightweight Foam Composite (LFC) ECM) is proposed to be developed as an alternative option for the next generation of ECMs. As proposed, the LFC ECM will enable construction and maintenance efficiencies while still achieving the same level of protection afforded by existing ECMs. Existing ECM designs are dominated by reinforced concrete solutions that engender significant potential debris hazards and construction costs due to their heavy nature. As part of this proposed Phase II effort, the Project Team aims to develop a prototype LFC ECM through high-fidelity physics-based (HFPB) analyses and proof-of-concept testing. The effort is to be performed over three years. In the Base year, dynamic material characterization testing and HFPB calculations will be used to optimize the LFC ECM typical roof panel. This optimized roof panel will then be manufactured and tested via quasi-static bending tests. In the Option 1 year, dynamic drop hammer tests will be performed on the optimized LFC ECM roof panel and 95% construction drawings and specifications for an LFC ECM will be generated. In the Option 2 year, test planning for a full-scale blast demonstration test will be performed.

Benefit:
The Lightweight Foam Composite (LFC) earth covered magazine (ECM) concept is a lightweight, energy-absorbing, durable, modular, and strong alternative to existing reinforced concrete (RC) ECM solutions. Its potential advantages include: Lightweight: The Modular Storage Magazine (MSM) ECM roof panel weighs roughly 130 psf while the LFC ECM roof panel weighs between 50 and 80 psf (depending on the lightweight concrete thickness). The reduced weight will limit transportation costs and crane requirements on site during construction. Additionally, the secondary debris hazard posed by a donor LFC ECM will be much reduced from that posed by an RC ECM. Superior O&M: An LFC ECM can be constructed totally of corrosion resistant materials (with the exception of the rebar cage in the lightweight concrete shell that is needed for lightning protection) that can be employed in harsh environments and thus minimize operations and maintenance (O&M) costs. Furthermore, its modular nature and simple connections allows for easy replacement if needed. Energy Absorption: Strategic positioning of energy absorbing foam is capable of dissipating significant airblast energy in a cost-effective manner. Inherent Strength: The slight arch shape optimizes the structural strength afforded by the FRP roof beams. Additionally, the arch curvature can be modified to relatively easily accommodate spans larger than 25 feet as well as limit the need for interior columns.

Keywords:
Polyurethane Foam, ECM, FRP, Fiber reinforced polymer, Composite, Modular, Lightweight, Earth Covered Magazine