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2017-09-19
Journal Article
2017-01-2018
Won Il Jung, Larry Lowe, Luis Rabelo, Gene Lee, Ojeong Kwon
Abstract Operator training using a weapon in a real-world environment is risky, expensive, time-consuming, and restricted to the given environment. In addition, governments are under intense scrutiny to provide security, yet they must also strive for efficiency and reduce spending. In other words, they must do more with less. Virtual simulation, is usually employed to solve these limitations. As the operator is trained to maximize weapon effectiveness, the effectiveness-focused training can be completed in an economical manner. Unfortunately, the training is completed in limited scenarios without objective levels of training factors for an individual operator to optimize the weapon effectiveness. Thus, the training will not be effective. For overcoming this problem, we suggest a methodology on guiding effectiveness-focused training of the weapon operator through usability assessments, big data, and Virtual and Constructive (VC) simulations.
2017-09-19
Technical Paper
2017-01-2121
Greg Parlier
The US Department of Defense (DoD) operates the most complex global supply chain in the world. However, effectively integrating production planning, maintenance operations, inventory systems, and distribution policies has been a persisting strategic challenge for the logistics enterprise supporting the DoD. Neither DoD nor the Congressional Budget Office has been able to establish a well-defined linkage between Operations and Maintenance resource funding levels and the resulting readiness of military units. For nearly three decades the Government Accountability Office has attributed these inadequacies to poor demand forecasting, ineffective inventory management, and inadequate strategic planning. To address these persisting problems the US Army established the project to Transform Army Supply Chains (TASC) in order to investigate the nature, causes, and consequences of demand uncertainty and supply variability.
2017-03-28
Technical Paper
2017-01-0257
Liang Wu, Fangwu Ma, Yongfeng Pu, HongBin Yin
Abstract This research focuses on an integration of two optimal tracking controllers, the active suspension controller and the rear-wheel steering controller, with the objective of improving vehicle performances in terms of maneuverability and safety by enhancing road holding capability and lateral stability. The active suspension controller adjusts the vehicle roll angle and utilizes the vertical force at each active suspension to boost road holding capability. On the other hand, the rear-wheel steering controller adjusts rear steering angles to use lateral force at each ground-tire contact point and amplify the vehicle’s ability to follow the desired yaw rate and sideslip angle during cornering maneuvers. Though the active attitude motion and mass shifting of car body may seem to hold relationship with lateral stability, its ability to evenly distribute vertical tire forces benefits the rear-wheel steering controller by enhancing the road holding capability.
2017-03-28
Technical Paper
2017-01-0259
Xinran Tao, John R. Wagner
Abstract Heat rejection in ground vehicle propulsion systems remains a challenge given variations in powertrain configurations, driving cycles, and ambient conditions as well as space constraints and available power budgets. An optimization strategy is proposed for engine radiator geometry size scaling to minimize the cooling system power consumption while satisfying both the heat removal rate requirement and the radiator dimension size limitation. A finite difference method (FDM) based on a heat exchanger model is introduced and utilized in the optimization design. The optimization technique searches for the best radiator core dimension solution over the design space, subject to different constraints. To validate the proposed heat exchanger model and optimization algorithm, a heavy duty military truck engine cooling system is investigated.
2017-03-28
Technical Paper
2017-01-0264
Venkatesh Babu, Ravi Thyagarajan, Jaisankar Ramalingam
Abstract In this paper, the capability of three methods of modelling detonation of high explosives (HE) buried in soil viz., (1) coupled discrete element & particle gas methods (DEM-PGM) (2) Structured - Arbitrary Lagrangian-Eulerian (S-ALE), and (3) Arbitrary Lagrangian-Eulerian (ALE), are investigated. The ALE method of modeling the effects of buried charges in soil is well known and widely used in blast simulations today [1]. Due to high computational costs, inconsistent robustness and long run times, alternate modeling methods such as Smoothed Particle Hydrodynamics (SPH) [2, 9] and DEM are gaining more traction. In all these methods, accuracy of the analysis relies not only on the fidelity of the soil and high explosive models but also on the robustness of fluid-structure interaction. These high-fidelity models are also useful in generating fast running models (FRM) useful for rapid generation of blast simulation results of acceptable accuracy.
2017-03-28
Technical Paper
2017-01-0261
Randolph Jones, Robert Marinier III, Frank Koss, Robert Bechtel, John A. Sauter
Abstract When evaluating new vehicle designs, modeling and simulation offer techniques to predict parameters such as maximum speed, fuel efficiency, turning radius, and the like. However, the measure of greatest interest is the likelihood of mission success. One approach to assessing the likelihood of mission success in simulation is to build behavior models, operating at the human decision-making level, that can execute realistic missions in simulation. This approach makes it possible to not only measure changes in mission success rates, but also to analyze the causes of mission failures. Layering behavior modeling and simulation on underlying models of equipment and components enables measurement of more conventional parameters such as time, fuel efficiency under realistic conditions, distance traveled, equipment used, and survivability.
2017-03-28
Technical Paper
2017-01-0263
Krishnaraj Udayachalam, Manan Trivedi, Ziliang Zheng, Amit Shrestha, Naeim Henein
Abstract SASOL IPK is a low cetane number synthetic fuel formed from coal by the Fischer-Tropsch process which can be used as an extender to JP8, currently used in military ground vehicles. This paper presents two surrogates developed considering the following criteria: (a) availability of kinetic combustion models for each component, (b) smallest number of components to reduce computation time and cost, (c) matching the following properties of target fuel DCN, distillation curve, density, LHV, MW and H/C ratio. The autoignition and combustion characteristics of the surrogates were validated in IQT according to ASTM D6890-10a. Surrogate formulation strategy involves an equation to calculate DCN of the surrogate mixture from the DCN of each component. The linear equation commonly used for such calculations was modified to include a multiplier, based on regression analysis, for each component to produces DCN values that agree well with the measured DCN in the IQT.
2017-03-28
Technical Paper
2017-01-0270
Richard Gerth, Ryan Howell
Abstract The recently published Lightweight Combat Vehicle Science and Technology Campaign [1] recommended the Army develop a quantitative understanding of the operational impact that weight reduction has to the Army and create appropriate metrics that would better reflect the performance trade with regards to weight. That paper raised the question of what a ton of weight is worth in operational effectiveness and cost. This paper is an attempt to clarify this complex topic. The impact of select programmatic considerations, operational considerations, and financial considerations are discussed. Throughout, the paper provides example analyses based on vehicle weight, performance, and cost data. The paper closes with a discussion of the issues presented, research recommendations, and closing comments.
2017-03-28
Technical Paper
2017-01-0274
Xueyu Zhang, Zoran Filipi
Abstract This paper presents the development of an electrochemical aging model of LiFePO4-Graphite battery based on single particle (SP) model. Solid electrolyte interphase (SEI) growth is considered as the aging mechanism. It is intended to provide both sufficient fidelity and computational efficiency required for integration within the HEV power management optimization framework. The model enables assessment of the battery aging rate by considering instantaneous lithium ion surface concentration rather than average concentration, thus enhancing the fidelity of predictions. In addition, an approximate analytical method is applied to speed up the calculation while preserving required accuracy. Next, this aging model are illustrated two applications. First is hybrid electric powertrain system model integration and simulation.
2017-03-28
Technical Paper
2017-01-0260
Yuanying Wang, Heath Hofmann, Denise Rizzo, Scott Shurin
Abstract This paper presents a computationally-efficient model of heat convection due to air circulation produced by rotor motion in the air gap of an electric machine. The model calculates heat flux at the boundaries of the rotor and stator as a function of the rotor and stator temperatures and rotor speed. It is shown that, under certain assumptions, this mapping has the homogeneity property. This property, among others, is used to pose a structure for the proposed model. The coefficients of the model are then determined by fitting the model to the results of a commercial Computational Fluid Dynamics (CFD) simulation program. The accuracy of the new model is compared to the CFD results, shown an error of less than 0.3% over the studied operating range.
2017-03-28
Journal Article
2017-01-0258
Mark Brudnak, James Walsh, Igor Baseski, Bryan LaRose
Abstract Laboratory based durability simulation has become an increasingly important component of vehicle system design validation and production release. It offers several advantages over field testing which has driven its adoption in the automotive and military sectors. Among these advantages are 1) repeatability, 2) earlier testing, 3) isolation of subsystems or components and 4) ability to compress and/or accelerate the testing. In this paper we present time-domain methods and techniques adapted, implemented and used at TARDEC to reduce the time required to perform a laboratory durability test of a full vehicle system, subsystem or component. Specifically, these methods approach a durability schedule holistically by considering all events/surfaces, repeats and channels of interest. They employ the standard Generic Stress Life (GSL) approach, utilizing rain flow cycle counting and a minimum-average method of identifying segments of the events which are less severe.
2017-03-28
Journal Article
2017-01-0272
Andrej Ivanco
Abstract Military vehicles experience a wide range of duty cycles depending on the place and purpose of their deployment. Vehicle fuel consumption directly depends on those use cases, which are ranging from patrolling during peace keeping operations to direct engagements in hostiles areas. Vehicle design should accommodate this wide range of operation modes to maximize the vehicle practicality during their service life. This paper aims to quantify the sensitivity of the powerpack design for a notional 15-ton series hybrid electric vehicle for two highly dynamic military drive cycles. The optimal design for a powerpack (engine coupled with a generator) will be separately determined for each of the use cases through a previously developed optimization routine that use the Genetic Algorithm. For each iteration of the Genetic Algorithm a design benchmarking was incorporated by using Dynamic Programming.
2017-03-28
Journal Article
2017-01-0271
Robert Jane, Gordon G. Parker, Wayne Weaver, Ronald Matthews, Denise Rizzo, Michael Cook
Abstract This paper considers optimal power management during the establishment of an expeditionary outpost using battery and vehicle assets for electrical generation. The first step in creating a new outpost is implementing the physical protection and barrier system. Afterwards, facilities that provide communications, fires, meals, and moral boosts are implemented that steadily increase the electrical load while dynamic events, such as patrols, can cause abrupt changes in the electrical load profile. Being able to create a fully functioning outpost within 72 hours is a typical objective where the electrical power generation starts with batteries, transitions to gasoline generators and is eventually replaced by diesel generators as the outpost matures.
2017-03-28
Journal Article
2017-01-0269
Doohyun Kim, Jason Martz, Angela Violi
Abstract The ignition delay time for direct injection compression ignition engines is determined by complex physical and chemical phenomena that prepare the injected liquid fuel for gas phase ignition. In this work, Computational Fluid Dynamics (CFD) simulations of a reacting spray within a constant volume spray chamber are conducted to investigate the relative importance of liquid fuel physical properties and oxidation chemistry on the ignition delay time. The simulations use multi-component surrogates that emulate the physical and chemical properties of petroleum-derived (Jet-A) and natural-gas-derived (S-8) jet fuels. Results from numerical experiments isolating the fuel physical property and chemistry effects show that fuel chemistry is significantly more important to ignition delay than fuel physical properties under the conditions studied.
2017-03-28
Journal Article
2017-01-0267
Tomasz Haupt, Gregory Henley, Angela Card, Michael S. Mazzola, Matthew Doude, Scott Shurin, Christopher Goodin
Abstract The Powertrain Analysis and Computational Environment (PACE) is a powertrain simulation tool that provides an advanced behavioral modeling capability for the powertrain subsystems of conventional or hybrid-electric vehicles. Due to its origins in Argonne National Lab’s Autonomie, PACE benefits from the reputation of Autonomie as a validated modeling tool capable of simulating the advanced hardware and control features of modern vehicle powertrains. However, unlike Autonomie that is developed and executed in Mathwork’s MATLAB/Simulink environment, PACE is developed in C++ and is targeted for High-Performance Computing (HPC) platforms. Indeed, PACE is used as one of several actors within a comprehensive ground vehicle co-simulation system (CRES-GV MERCURY): during a single MERCURY run, thousands of concurrent PACE instances interact with other high-performance, distributed MERCURY components.
2017-03-28
Journal Article
2017-01-0268
Venkatesh Babu, Richard Gerth
Abstract The aim of this analysis was to model the effect of adding stiffening ribs in structural aluminum components by friction stir processing (FSP) Nano material into the aluminum matrix. These stiffening ribs could dampen, redirect, or otherwise alter the transmission of energy waves created from automotive, ballistic, or blast shocks to improve noise, vibration, and harshness (NVH) and structural integrity (reduced joint stress) response. Since the ribs are not created by geometry changes they can be space efficient and deflect blast / ballistic energy better than geometry ribbing, resulting in a lighter weight solution. The blast and ballistic performance of different FSP rib patterns in AL 5182 and AL 7075 were simulated and compared to the performance of an equivalent weight of RHA plate FSP helps to increase localized strength and stiffness of the base metal, while achieving light weighting of the base metal.
2017-03-28
Journal Article
2017-01-0273
Chris Goodin, Jeremy Mange, Sara Pace, Thomas Skorupa, Daniel Kedziorek, Jody Priddy, Larry Lynch
Abstract Mercury is a high-fidelity, physics-based object-oriented software for conducting simulations of vehicle performance evaluations for requirements and engineering metrics. Integrating cutting-edge, massively parallel modeling techniques for soft, cohesive and dry granular soil that will integrate state-of-the-art soil simulation with high-fidelity multi-body dynamics and powertrain modeling to provide a comprehensive mobility simulator for ground vehicles. The Mercury implements the Chrono::Vehicle dynamics library for vehicle dynamics, which provides multi-body dynamic simulation of wheeled and tracked vehicles. The powertrain is modeled using the Powertrain Analysis Computational Environment (PACE), a behavior-based powertrain analysis based on the U.S. Department of Energy’s Autonomie software. Vehicle -terrain interaction (VTI) is simulated with the Ground Contact Element (GCE), which provides forces to the Chrono-vehicle solver.
2016-11-07
Technical Paper
2016-22-0009
Hollie A. Pietsch, Kelly E. Bosch, David R. Weyland, E. Meade Spratley, Kyvory A. Henderson, Robert S. Salzar, Terrance A. Smith, Brandon M. Sagara, Constantine K. Demetropoulos, Christopher J. Dooley, Andrew C. Merkle
Three laboratory simulated sub-injurious under-body blast (UBB) test conditions were conducted with whole-body Post Mortem Human Surrogates (PMHS) and the Warrior Assessment Injury Manikin (WIAMan) Technology Demonstrator (TD) to establish and assess UBB biofidelity of the WIAMan TD. Test conditions included a rigid floor and rigid seat with independently varied pulses. On the floor, peak velocities of 4 m/s and 6 m/s were applied with a 5 ms time to peak (TTP). The seat peak velocity was 4 m/s with varied TTP of 5 and 10 ms. Tests were conducted with and without personal protective equipment (PPE). PMHS response data was compiled into preliminary biofidelity response corridors (BRCs), which served as evaluation metrics for the WIAMan TD. Each WIAMan TD response was evaluated against the PMHS preliminary BRC for the loading and unloading phase of the signal time history using Correlation Analysis (CORA) software to assign a numerical score between 0 and 1.
2016-11-07
Technical Paper
2016-22-0010
Frank A. Pintar, Michael B. Schlick, Narayan Yoganandan, Liming Voo, Andrew C. Merkle, Michael Kleinberger
A new anthropomorphic test device (ATD) is being developed by the US Army to be responsive to vertical loading during a vehicle underbody blast event. To obtain design parameters for the new ATD, a series of non-injurious tests were conducted to derive biofidelity response corridors for the foot-ankle complex under vertical loading. Isolated post mortem human surrogate (PMHS) lower leg specimens were tested with and without military boot and in different initial foot-ankle positions. Instrumentation included a six-axis load cell at the proximal end, three-axis accelerometers at proximal and distal tibia, and calcaneus, and strain gages. Average proximal tibia axial forces for a neutral-positioned foot were about 2 kN for a 4 m/s test, 4 kN for 6 m/s test and 6 kN for an 8 m/s test. The force time-to-peak values were from 3 to 5 msec and calcaneus acceleration rise times were 2 to 8 msec.
2016-04-05
Technical Paper
2016-01-1525
Anil Kalra, Kartik Somasundram, Ming Shen, Vishal Gupta, Clifford C. Chou, Feng Zhu
Abstract Numerical models of Hybrid III had been widely used to study the effect of underbody blast loading on lower extremities. These models had been primarily validated for automotive loading conditions of shorter magnitude in longer time span which are different than typical blast loading conditions of higher magnitude of shorter duration. Therefore, additional strain rate dependent material models were used to validate lower extremity of LSTC Hybrid III model for such loading conditions. Current study focuses on analyzing the mitigating effect of combat boots in injury responses with the help of validated LSTC Hybrid III model. Numerical simulations were run for various impactor speeds using validated LSTC Hybrid III model without any boot (bare foot) and with combat boot.
2016-04-05
Journal Article
2016-01-0317
Yuanzhan Wang, Jason B. Siegel, Anna G. Stefanopoulou
Abstract This paper addresses scheduling of quantized power levels (including part load operation and startup/shutdown periods) for a propane powered solid oxide fuel cell (SOFC) hybridized with a lithium-ion battery for a tracked mobile robot. The military requires silent operation and long duration missions, which cannot be met by batteries alone due to low energy density or with combustion engines due to noise. To meet this need we consider an SOFC operated at a few discrete power levels where maximum system efficiency can be achieved. The fuel efficiency decreases during transients and resulting thermal gradients lead to stress and degradation of the stack; therefore switching power levels should be minimized. Excess generated energy is used to charge the battery, but when it’s fully charged the SOFC should be turned off to conserve fuel.
2016-04-05
Journal Article
2016-01-0313
Andrej Ivanco, Kan Zhou, Heath Hofmann, Zoran S. Filipi
Abstract Design of military vehicle needs to meet often conflicting requirements such as high mobility, excellent fuel efficiency and survivability, with acceptable cost. In order to reduce the development cost, time and associated risk, as many of the design questions as possible need to be addressed with advanced simulation tools. This paper describes a methodology to design a fuel efficient powerpack unit for a series hybrid electric military vehicle, with emphasis on the e-machine design. The proposed methodology builds on previously published Finite element based analysis to capture basic design features of the generator with three variables, and couples it with a model reduction technique to rapidly re-design the generator with desired fidelity. The generator is mated to an off the shelf engine to form a powerpack, which is subsequently evaluated over a representative military drive cycles.
2016-04-05
Technical Paper
2016-01-0314
Larry Michaels, Curtis G. Adams, Michael Juskiewicz
Abstract A simulation approach is defined that integrates a military mission assessment tool (One Semi-Automated Forces) with a commercial automotive control/energy consumption development tool (Autonomie). The objective is to enable vehicle energy utilization and fuel consumption impact assessments relative to US Army mission effectiveness and commercial drive cycles. The approach to this integration will be described, along with its potential to meet its objectives.
2016-04-05
Journal Article
2016-01-0316
Dorin Drignei, Zissimos Mourelatos, Ervisa Kosova, Jingwen Hu, Matthew Reed, Jonathan Rupp, Rebekah Gruber, Risa Scherer
Abstract We have recently obtained experimental data and used them to develop computational models to quantify occupant impact responses and injury risks for military vehicles during frontal crashes. The number of experimental tests and model runs are however, relatively small due to their high cost. While this is true across the auto industry, it is particularly critical for the Army and other government agencies operating under tight budget constraints. In this study we investigate through statistical simulations how the injury risk varies if a large number of experimental tests were conducted. We show that the injury risk distribution is skewed to the right implying that, although most physical tests result in a small injury risk, there are occasional physical tests for which the injury risk is extremely large. We compute the probabilities of such events and use them to identify optimum design conditions to minimize such probabilities.
2016-04-05
Journal Article
2016-01-0310
Xinran Tao, John R. Wagner
Abstract The pursuit of greater fuel economy in internal combustion engines requires the optimization of all subsystems including thermal management. The reduction of cooling power required by the electromechanical coolant pump, radiator fan(s), and thermal valve demands real time control strategies. To maintain the engine temperature within prescribed limits for different operating conditions, the continual estimation of the heat removal needs and the synergistic operation of the cooling system components must be accomplished. The reductions in thermal management power consumption can be achieved by avoiding unnecessary overcooling efforts which are often accommodated by extreme thermostat valve positions. In this paper, an optimal nonlinear controller for a military M-ATV engine cooling system will be presented. The prescribed engine coolant temperature will be tracked while minimizing the pump, fan(s), and valve power usage.
2016-04-05
Technical Paper
2016-01-0312
Robert S. Jane, Gordon G. Parker, Wayne Weaver, Denise M. Rizzo
Abstract Vehicles with power exporting capability are microgrids since they possess electrical power generation, onboard loads, energy storage, and the ability to interconnect. The unique load and silent watch requirements of some military vehicles make them particularly well-suited to augment stationary power grids to increase power resiliency and capability. Connecting multiple vehicles in a peer-to-peer arrangement or to a stationary grid requires scalable power management strategies to accommodate the possibly large numbers of assets. This paper describes a military ground vehicle power management scheme for vehicle-to-grid applications. The particular focus is overall fuel consumption reduction of the mixed asset inventory of military vehicles with diesel generators typically used in small unit outposts.
2016-04-05
Journal Article
2016-01-0307
Weiran Jiang, Alyssa Bennett, Nickolas Vlahopoulos, Matthew Castanier, Ravi Thyagarajan
Abstract Assessing the dynamic performance of multilayer plates subjected to impulsive loading is of interest for identifying configurations that either absorb energy or transmit the energy in the transverse directions, thereby mitigating the through-thickness energy propagation. A reduced-order modeling approach is presented in this paper for rapidly evaluating the structural dynamic performance of various multilayer plate designs. The new approach is based on the reverberation matrix method (RMM) with the theory of generalized rays for fast analysis of the structural dynamic characteristics of multilayer plates. In the RMM model, the waves radiated from the dynamic load are reflected and refracted at each interface between layers, and the waves within each layer are transmitted with a phase lag. These two phenomena are represented by the global scattering matrix and the global phase matrix, respectively.
2016-04-05
Technical Paper
2016-01-0308
Tomasz A. Haupt, Angela E. Card, Matthew Doude, Michael S. Mazzola, Scott Shurin, Alan Hufnagel
Abstract The Powertrain Analysis and Computational Environment (PACE) is a forward-looking powertrain simulation tool that is ready for a High-Performance Computing (HPC) environment. The code, written in C++, is one actor in a comprehensive ground vehicle co-simulation architecture being developed by the CREATE-GV program. PACE provides an advanced behavioral modeling capability for the powertrain subsystem of a conventional or hybrid-electric vehicle that exploits the idea of reusable vehicle modeling that underpins the Autonomie modeling environment developed by the Argonne National Laboratory. PACE permits the user to define a powertrain in Autonomie, which requires a single desktop license for MATLAB/Simulink, and port it to a cluster computer where PACE runs with an open-source BSD-3 license so that it can be distributed to as many nodes as needed.
2016-04-05
Journal Article
2016-01-1404
Steven E. Hodges
Abstract Fire protection, active and passive, has been, and is, an important area of concern during the design, development and deployment phases for all modern ground vehicles. All US military vehicles carry handheld fire extinguishers, and many tactical and all combat vehicles have automatic fire protection systems that protect the crew, engine, and in some cases, external components such as fuel tanks and wheels, from potentially catastrophic combat events involving fire. Vehicle designs also mitigate fire hazards by separating the vehicle occupants from the most flammable materials, e.g., fuel and ammunition, as much as practical. Explosion protection of the crew and passengers in military vehicles is a unique application with unique requirements that must balance suppression actions with safety limits.
2016-04-05
Journal Article
2016-01-0309
Matthew Reed, Sheila Ebert-Hamilton
Abstract This study evaluated the ISO 5353 Seat Index Point Tool (SIPT) as an alternative to the SAE J826 H-point manikin for measuring military seats. A tool was fabricated based on the ISO specification and a custom back-angle measurement probe was designed and fitted to the SIPT. Comparisons between the two tools in a wide range of seating conditions showed that the mean SIP location was 5 mm aft of the H-point, with a standard deviation of 7.8 mm. Vertical location was not significantly different between the two tools (mean - 0.7 mm, sd 4.0 mm). A high correlation (r=0.9) was observed between the back angle measurements from the two tools. The SIPT was slightly more repeatable across installations and installers than the J826 manikin, with most of the discrepancy arising from situations with flat seat cushion angles and either unusually upright or reclined back angles that caused the J826 manikin to be unstable.
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