Blast Mitigation Seat Analysis: Assessment of the Effect of Personal Protective Equipment on the 5th Percentile Female Anthropomorphic Test Device Performance in Drop Tower Evaluations

To address the lack of knowledge on the quantitative effects of Personal Protective Equipment (PPE) on the small occupant, 55 drop tower tests were conducted and the resulting responses were evaluated. A previous technical publication evaluated the results of drop tower testing of twelve models of blast energy-attenuating seats1. That study assessed the data recorded from three sizes of anthropomorphic test devices, or ATDs, including the Hybrid III 5th percentile female, the Hybrid III 50th percentile male, and the Hybrid III 95th percentile male. The forces, moments, and accelerations from the ATDs were compared to Injury Assessment Reference Values (IARVs) to validate the drop tower methodology and to evaluate the appropriateness of the IARVs developed for the three occupant sizes. The data review revealed that the maximum lumbar compression loads recorded by the ATDs was an effective “go/no-go” criteria for judging seat performance, and that the 5th percentile female ATD, or small occupant, was the most difficult to pass the corresponding lumbar compression IARV. Additionally, the 5th percentile female ATD exceeded its corresponding IARV for upper neck compression, leading to the motivation for this study; the data set from the previous technical publication was used in this study. Historically, blast mitigation seats are designed to accommodate the average sized occupant, or 50th percentile male. Moving forward, there is a new emphasis on extending the protection afforded to the full military population, including the small female. The data presented in this paper seeks to determine the effect of PPE on the lumbar compression and upper neck loads for the small occupant.

Enabling the Virtual Navy Enterprise

The Virtual Navy Enterprise encompasses those Navy organizations, shipbuilders, integrators, and suppliers necessary to provide life cycle support for the fleet. The efficiency of this virtual enterprise is typically hampered by lack of interoperability and effective data exchange. This is particularly true for activities, such as Ship Alterations, that involve several different organizations. The ISE-6 team worked with NSWC Port Hueneme Division to develop a technical approach that fosters interoperability across the Virtual Navy Enterprise. This extends the ISE-6 Phase 1 work with the PLCS standard to include exchange of technical publication data using the S1000D international standard, which allows exchange of design and logistics data between ISEAs, NAVSEA, shipyards, and OEMs. A key result was the ability to automate identification of change impacts to technical publications; reducing the costs to evaluate changes and supporting cost benefit analysis and design trade studies. The ISE-6 team also worked with the US Navy S1000D Working Group and DDG 1000 Technical Data Working Group to help formulate S1000D data module naming rules, metadata use for efficient searching, and business rule definition. The ISE-6 team conducted a demonstration of this approach for a Ship Alteration resulting from a vendor change to the radar oscillator. The ISEA updates the radar product data and technical publication to reflect this change. An Engineering Change is coordinated between NAVSSES and the Shipyard to implement the SCD. The changes are passed, via PLCS and S1000D, to the shipyard IDE resulting in an associated change to the HVAC system to accommodate the increased heat load. The Shipyard develops a design change. The S1000D data modules affected by the AC Unit change are identified by the Shipyard and updated to reflect the change.