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This paper presents a computational framework for the physics-based simulation of light vehicles operating on discrete terrain. The focus is on characterizing through simulation the mobility of vehicles that weigh 1000 pounds or less, such as a reconnaissance robot. The terrain is considered to be deformable and is represented as a collection of bodies of spherical shape. The modeling stage relies on a novel formulation of the frictional contact problem that requires at each time step of the numerical simulation the solution of an optimization problem. The proposed computational framework, when run on ubiquitous Graphics Processing Unit (GPU) cards, allows the simulation of systems in which the terrain is represented by more than 0.5 million bodies leading to problems with more than one million degrees of freedom.

This paper discusses a new Department of Defense (DoD) initiative focused on the development of new generation of MBS computer software that have capabilities and features that are not provided by existing MBS software technology. This three-decade old technology fails to meet new challenges of developing more detailed models in which the effects of significant changes in geometry and large deformations cannot be ignored. New applications require accurate continuum mechanics based vehicle/soil interaction models, belt and chain drive models, efficient and accurate continuum based tire models, cable models used in rescue missions, models that accurately capture large deformations due to thermal and excessive loads, more accurate bio-mechanics models for ligaments, muscles, and soft tissues (LMST), etc.

There are 80 million light trucks on the road today with suboptimal aerodynamic forms. Previous research has found that several miles per gallon can be saved by specifically tailoring truck bodies for reduced aerodynamic drag. Even greater savings can be obtained if the shape of the trucks is numerically optimized. This could reduce fuel consumption in the United States by billions of gallons per year. This paper demonstrates a method for drag reduction using CFD and traditional numerical optimization techniques. A method for efficient design variable reduction for CFD optimization of three-dimensional shapes is also presented and applied to light trucks. The optimized form is then physically constructed and installed on a recent model pickup truck. The vehicle is tested in several configurations and the effects on fuel economy are compared to the CFD prediction.

This document presents the results of computer-based, vehicle dynamics performance assessments of Future Truck concepts with such features as a variable height, hydraulic, trailing arm suspension, skid steering, and in-hub electric drive motors. Fully three-dimensional Future Truck models were created using a commercially available modeling and simulation methodology and limited validation studies were performed by comparing model predictions with baseline, validated model predictions from another vehicle in the same size and class as the Future Truck concept vehicles. The models were considered accurate enough to predict various aspects of ride quality and stability performance, critical to US Army Objective Force mission needs. One-to-one comparisons of the Future Truck concepts and a standard, solid-axle, Heavy Tactical Vehicle (HTV) operating in various terrain and obstacle negotiation conditions were performed.

In support of Department of Defense (DOD) mandated acquisition reform initiatives to reduce vehicle related life cycle costs and timelines, the Tank-automotive and Armaments Research, Development and Engineering Center (TARDEC) is using simulation-based acquisition strategies to investigate the dynamic performance of wheeled and tracked ground vehicles throughout the vehicle development, testing, and fielding life cycle process. The paper will describe how modeling and simulation (M&S) is applied to answer a wide variety of design and performance evaluation questions and will depict a series of simulation-based engineering projects that build on the Army's simulation investments as a tool to investigate and answer real-world vehicle design, acquisition, and engineering support questions.

This report describes a computer-based modeling, simulation and graphical animation effort that addresses the dynamic performance, stability, and handling of the Palletized Load System (PLS) truck/trailer combination being considered for use as a transporter for a 19,000 liter Bulk Fuel and Water Carrier variant. The US Army has initiated an effort to develop and evaluate concepts to explore alternative uses for the PLS. The US Army Tank-automotive and Armaments Command, Research, Development, & Engineering Center (TACOM-TARDEC), has been task to determine and develop viable alternatives to be used with the PLS to include volume water and fuel transportation as well as specialized combat engineer missions.