Browse Topic: Parts
ABSTRACT A discussion on the utility of physics-based compact thermal models to guide the design, integration, operation and control of thermally sensitive vehicle components is presented. Effective component selection requires honest and accurate representation of the key performance attributes expressed by physics-based models. Parallel developments and lessons learned from the Electronics Industry on component packaging and characterization is discussed. An example application of a physics-based model driven design is presented for an Electrical Energy Dissipater design used on typical hybrid vehicles. Low fidelity models are used early in the design to support system requirements decomposition into discreet design attributes. High fidelity thermal and electromagnetic models are used to explore the design space and to optimize performance metrics. Accurate and robust reduced order thermal models are used for the continuous prognostic, diagnostic monitoring and control of the device
ABSTRACT Model based design techniques are being used increasingly to predict vehicle performance before building prototype hardware. Tools like ADAMS and Simulink enable very detailed models of suspension components to be developed so vehicle performance can be accurately predicted. In creating models of vehicle systems, often there is a question about how much component detail or model fidelity is required to accurately model system performance. This paper addresses this question for modeling shock absorber performance by comparing a low fidelity and high fidelity shock absorber model. A high fidelity and low fidelity mathematical model of a shock absorber was developed. The low fidelity shock absorber model was parameterized according to real shock absorber hardware dimensions. Shock absorber force vs. velocity curves were calculated in Simulink. The results from the low fidelity and high fidelity model were compared to shock absorber force vs. velocity test results. New vehicle
ABSTRACT The M1 Abrams will be the primary heavy combat vehicle for the US military for years to come. Improvements to the M1 that increase reliability and reduce maintenance will have a multi-year payback. The M1 engine intake plenum seal couples the air intake plenum to the turbine inlet, and has opportunities for improvement to reduce leakage and intake of FOD (foreign object debris) into the engine, which causes damage and premature wear of expensive components
ABSTRACT In this paper a new bolt attachment method was explored, where the attaching bolts were divided into two sets. The first set of bolts was tightened and was used to connect the underbody plate to the hull under ordinary operations. The second set of bolts connecting the plate and the hull were not tightened and had some extra axial freedom. Under blast loading, the first set of bolts would break due to high tensile and shear loads, but the second set of bolts would survive due to extra axial freedom which allows the plate and the hull vibrate and separate from each other to a certain extent. A simulation model was developed to verify this concept. Three underbody plate-hull connection approaches were simulated and analyzed: 1) all tightened bolts, 2) some bolts not fully seated, 3) all bolts not fully seated. The simulation results show that with option 1), 100% of the bolts broke under the blast loading. With option 2) the not fully seated bolts survived and continued to
ABSTRACT The HMPT500-3 is a split torque path hydrostatic / mechanical continuously variable transmission used in the Bradley Fighting Vehicle. Power transmission and steering is accomplished through the interaction of six planetary gear sets and two variable displacement hydrostatic pump / motor units (HSUs). Power flow in the HMPT500-3 is extremely complex, with numerous feedback paths within the planetary gear train. Without a clearly defined power flow path from gear set to gear set, the analysis cannot be handled in the conventional stepwise manner. The complete speed and torque equation sets must be solved simultaneously for all components. A linear algebraic approach was developed to model forward operation of the HMPT500-3 without steering. The left and right HSUs are lumped in a single unit, and the steering differential is ignored. A reduced set of 14 simultaneous equations for speed and 14 simultaneous equations for torque enable modeling of the ideal (lossless) power flow
ABSTRACT Military vehicle survivability can be enhanced by implementing Lightweight Fuel Tanks with an Engineered Self-Sealing and Energy Absorbing solution. A thin walled plastic or aluminum fuel tank with an outer self-sealing protection coating and a properly installed ballistic baffle provide increased sealing performance as compared to amour protected fuel tank. Design features include reduced weight penalty, survivability, self-sealing against kinetic energy threats, maximum fuel in space claim, flexible design, and low tooling charges. Citation: Stuck, LW, “Self Sealing Fuel Tanks in Vehicles Without Armor”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 10-12, 2021
ABSTRACT A 3D printed battery bracket is strengthened via post-print thermal annealing, demonstrating a transitionable approach for additive manufacturing of robust, high performance thermoplastic components. Citation: E. D. Wetzel, R. Dunn, L. J. Holmes, K. Hart, J. Park, and M. Ludkey, “Thermally Annealed, High Strength 3D Printed Thermoplastic Battery Bracket for M998,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022
ABSTRACT Motorized ground forces spend considerable resources in equipping for situational awareness capabilities. Given requirements spanning command, control, surveillance, and reconnaissance of a battlefield, there has been no single mast technology that can support each of these with elevated sensors and weapons. A tough, extremely low weight modular mast system has been designed to be quickly attached or removed from a ground vehicle to provide different operational capabilities depending on the payload. The design allows for easy modification to fit functional needs on different vehicles and platforms. At the heart of the technology is a proprietary super-fiber pressurized tube which elevates the payload on a column of moderate gas pressure eliminating cumbersome hydraulic/mechanical systems. An internal, simple alignment system and gyroscope-maintained verticality allow a stable, elevated platform without introducing instability to the vehicle. The system is capable of
ABSTRACT Variable displacement pumps have been used in automotive transmissions for decades. L3T had high confidence that a Variable Displacement Oil (VDO) pump would increase overall transmission efficiency. An off-the-shelf (OTS) or OTS modified pump in this pressure and flow range was not found. Therefore, a VDO pump is being developed with the known risk of replacing a highly reliable pump with a new better performing pump of unknown reliability. In this document the development of this VDO pump is discussed. Initial testing of the VDO pump demonstrated an average 25HP savings in pumping losses throughout the transmission operating ranges. At this point, durability testing has not been performed
ABSTRACT The key to vehicle survivability in a combat or otherwise hostile environment is the capability to quickly resupply critical parts. Rapid production of hard to obtain components within the theater of operations can significantly increase the availability of combat vehicles or other equipment. Additive manufacturing enables significant reduction in lead time for these components and thus offers an enhancement of combat capability. However, AM operations have specific environmental and support requirements in order to function. In partnership with CESI and CAPSA, AddUp has developed a unique concept of a “modular plant” called the Anywhere Additive Factory. The unit can be adjusted to meet the manufacturing requirements and volumes needed, while also being easily dismantled and moved to another location. Citation: S. Pexton, “The FlexCare Deployable Additive Manufacturing Printing Facility”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium
ABSTRACT The United States Army is leveraging Advanced Manufacturing (AdvM) methods to solve both operational and tactical readiness gaps. AdvM includes not only Additive Manufacturing (AM), but also traditional manufacturing capabilities in the field and at Army production facilities. The Tank-Armaments and automotive Command (TACOM) and the Ground Vehicles Systems Center (GVSC) Materials-AdvM Branch have developed a strategy of five critical path key words oriented on three Lines of Effort (LOE) that enables a disciplined process to deliver final use qualified parts manufactured by the Organic Industrial Base (OIB) as an alternate source of supply that will improve readiness of TACOM’s combat and tactical wheeled fleets. Additionally, an alternate critical path has been developed to provide limited use parts for Battle Damage and Repair (BDAR). Citation: P. Burton, N. Kott, A. Kruz, A. Batjer, “Path to 450 Parts Qualified for Advanced Manufacturing”, In Proceedings of the Ground
ABSTRACT This paper describes a software infrastructure made up of tools and libraries designed to assist developers in implementing computational dynamics applications running on heterogeneous and distributed computing environments. Together, these tools and libraries compose a so called Heterogeneous Computing Template (HCT). The underlying theme of the solution approach embraced by HCT is that of partitioning the domain of interest into a number of sub-domains that are each managed by a separate core/accelerator (CPU/GPU) pair. The five components at the core of HCT, which ultimately enable the distributed/heterogeneous computing approach to large-scale dynamical system simulation, are as follows: (a) a method for the geometric domain decomposition; (b) methods for proximity computation or collision detection; (c) support for moving data within the heterogeneous hardware ecosystem to mirror the migration of simulation elements from subdomain to subdomain; (d) parallel numerical
ABSTRACT The following paper describes the new SAPA automatic transmissions for the future military vehicles. The very high mobility requirements, the reclaim of weight, power & space and the actual relevance of the fuel consumption require a rethinking and a new vision of the automatic transmission concept and design. This is what SAPA has been working on for the last 12 years obtaining excellent technical and commercial results, a concept aimed at reducing the power losses of the conventional powershifting transmission eliminating the torque converter, reducing the spin losses -due to hydraulic pumps and friction discs-, and improving vehicle mobility on variable terrain situations as off-road
ABSTRACT Curtiss-Wright has developed an acoustic based sensor technology for measuring friction, shock, and dynamic load transfer between moving parts in machinery. This technology provides a means of detecting and analyzing machine structure borne ultrasonic frequency sounds caused by friction and shock events between the moving parts of the machine. Electrical signals from the sensors are amplified and filtered to remove unwanted low frequency vibration energy. The resulting data is analyzed as a computed stress wave energy value that considers the amplitude, shape, duration and rates of all friction and shock events that occur during a reference time interval. The ability to separate stress waves from the lower frequency operational noise makes this technology capable of detecting damaged gears/bearings and changes in lubrication in equipment earlier than other techniques, and before failure progression increases cost of repair. Already TRL9 in adjacent industries, this technology
ABSTRACT A detailed methodology employing a system model of a tracked vehicle with a gun turret is used to analyze the stresses and loads applied to the gun mount as a result of gun firing events. The vehicle system model combines a Virtual Lab.Motion model of the tracked vehicle and gun mount which includes track super element, flexible gun mount body, and a beam element representation of the gun and gun tube sleeve coupled with a MATLAB/Simulink model of the hydraulic/pneumatic recoil system and gun pointing control system. This coupled system model with flexible components is needed for this analysis to determine the portion of the impulse that results in gun mount deformation. A brief overview of the vehicle system model, a detailed description of the gun mount model, and analysis of the gun mount loads and stress is included
This specification covers a premium aircraft-quality, low-alloy steel in the form of bars, forgings, mechanical tubing, and forging stock
This specification defines the requirements for a grooved clamp coupling and flanges suitable for joining intermediate pressure and temperature ducting in aircraft air systems. The rigid coupling joint assembly, hereafter referred to as "the joint", shall operate within the temperature range of -65 °F to +800 °F
This test method provides a standardized procedure for evaluating the electrochemical resistance of automotive coolant hose and materials. Electrochemical degradation has been determined to be a major cause of EPDM coolant system hose failures. The test method consists of a procedure which induces voltage to a test specimen while it is exposed to a water/coolant solution. Method #1, referred to as a “Brabolyzer” test, is a whole hose test. Method #2, referred to as a “U” tube test, uses cured plate samples or plates prepared from tube material removed from hose (Method No. 2 is intended as a screening test only). Any test parameters other than those specified in this SAE Recommended Practice, are to be agreed to by the tester and the requester
This test code describes tests for determining characteristics of hydraulic positive displacement pumps used on off-road self-propelled work machines as referenced in SAE J1116
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