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Journal Article

Numerical Analysis of Blast Protection Improvement of an Armored Vehicle Cab by Composite Armors and Anti-Shock Seats

2018-12-05
Abstract The objective of this article is to evaluate the effects of different blast protective modules to military vehicle structures and occupants. The dynamic responses of the V-shape integral basic armor, the add-on honeycomb sandwich structure module, and the anti-shock seat-dummy system were simulated and analyzed. The improvements of occupant survivability by different protective modules were compared using occupant injury criteria. The integral armored cab can maintain the integrity of the cab body structure. The add-on honeycomb sandwich armor reduces the peak structural deformation and velocity of the cab floor by 34.9% and 47.4%, respectively, compared with the cab with integral armors only. The integral armored cab with the anti-shock seat or the honeycomb sandwich structures reduces the occupant shock responses below the injury criteria. For different blast threat intensities, the selection of appropriate protective modules can meet protection requirements.
Journal Article

Nonlinear Multi-Fidelity Bayesian Optimization: An Application in the Design of Blast Mitigating Structures

2022-03-29
2022-01-0790
A common scenario in engineering design is the availability of several black-box functions that describe an event with different levels of accuracy and evaluation cost. Solely employing the highest fidelity, often the most expensive, black-box function leads to lengthy and costly design cycles. Multi-fidelity modeling improves the efficiency of the design cycle by combining information from a small set of observations of the high-fidelity function and large sets of observations of the low-fidelity, fast-to-evaluate functions. In the context of Bayesian optimization, the most popular multi-fidelity model is the auto-regressive (AR) model, also known as the co-kriging surrogate. The main building block of the AR model is a weighted sum of two Gaussian processes (GPs). Therefore, the AR model is well suited to exploit information generated by sources that present strong linear correlations.
Technical Paper

Human Shoulder Response to Lateral Impact in Intermediate Loading Conditions Between High-Velocity, Short-Duration and Low-Velocity, Long-Duration

2018-11-12
2018-22-0008
The EuroSID-2re (ES-2re) Anthropomorphic Test Device (ATD) commonly known as the crash test dummy is also used in the military domain to assess the risk of injury of armored vehicles occupants from lateral impact. The loading conditions range from low velocity - long duration impacts (4 m/s - 50 ms) similar to the automotive domain, to high velocity - short duration impacts (28 m/s - 3 ms) corresponding to cases where the panel deforms under an explosion. The human shoulder response to lateral impact was investigated at bounds of the loading condition spectrum previously mentioned, and also at intermediate conditions (14 m/s - 9 ms) in previous studies. The aim of the current study is to provide additional insight at the intermediate loading conditions which are not found in the literature.
Technical Paper

Human Foot-Ankle Injuries and Associated Risk Curves from Under Body Blast Loading Conditions

2017-11-13
2017-22-0006
Under body blast (UBB) loading to military transport vehicles is known to cause foot-ankle fractures to occupants due to energy transfer from the vehicle floor to the feet of the soldier. The soldier posture, the proximity of the event with respect to the soldier, the personal protective equipment (PPE) and age/sex of the soldier are some variables that can influence injury severity and injury patterns. Recently conducted experiments to simulate the loading environment to the human foot/ankle in UBB events (~5ms rise time) with variables such as posture, age and PPE were used for the current study. The objective of this study was to determine statistically if these variables affected the primary injury predictors, and develop injury risk curves. Fifty below-knee post mortem human surrogate (PMHS) legs were used for statistical analysis. Injuries to specimens involved isolated and multiple fractures of varying severity.
Magazine

Tech Briefs: August 2018

2018-08-01
Designing a High-Speed Decoy Unmanned Aerial Vehicle (UAV) Using Thermoplastics in Aerospace Applications In-Flight Real-Time Avionics Adaptation Using Turbine Flow Meters for Aerospace Test and Measurement Applications Communicating from Space: The Front End of Multiscale Modeling Laser-Based System Could Expand Space-to-Ground Communication Hydraulic Testing of Polymer Matrix Composite 102mm Tube Section Research could lead to development of a composite material that can be processed at a low temperature and still be used at 1000°F. Permeation Tests on Polypropylene Fiber Materials Study attempts to determine if polypropylene nanofiber materials can be used in air filtration systems to remove toxic vapors. Inter-Laboratory Combat Helmet Blunt Impact Test Method Comparison Ensuring consistent test methods could reduce the risk of head injuries.
Magazine

Tech Briefs: October 2018

2018-10-01
Detecting Drones with Doppler-Based Radar Digital Transformation for a Connected Enterprise Using Electromagnetic Brakes to Keep Thrust Reversers in Place Thermostatic Solutions for Temperature Control Applications Bringing RF into the Embedded World: It's Time Compact Power Amplifier Solution for Electronic Warfare Burner Rig Testing of A500® C/SiC Test method simulates, in a laboratory environment, the service conditions ceramic-matrix composite material would experience in turbine engine exhaust applications. Space Debris Orbit and Attitude Prediction for Enhanced and Efficient Space Situational Awareness Developing accurate models to predict the behavior of manmade debris in space could be the key to preventing collisions with satellites. Maintaining Enterprise Resiliency Via Kaleidoscopic Adaption and Transformation of Software Services (MEERKATS) Implementing new technologies to create a more resilient, secure cloud computing environment.
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