Browse Topic: Bodies and Structures

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The scope of this SAE Aerospace Information Report (AIR) is to discuss factors affecting visibility of aircraft navigation and anticollision lights, enabling those concerned with their use to have a better technical understanding of such factors, and to aid in exercising appropriate judgment in the many possible flight eventualities
A-20B Exterior Lighting Committee
The information in this document is intended to apply to commercial jet transport category airplanes that incorporate plastic (polycarbonate or acrylic) lenses on exterior light assemblies, or are being considered for such an application as opposed to glass lens designs. Exterior lighting applications include position light assemblies, anticollision light asemblies, and landing light assemblies. However, much of the material provided herein is general in nature and is directly applicable to many aircraft categories including, but not limited to, helicopters, general aviation aircraft, and military aircraft
A-20B Exterior Lighting Committee
This SAE Standard provides requirements, test procedures, and installation guidelines for clearance, sidemarker, and identification lamps intended for use on vehicles 2032 mm or more in overall width. Sidemarker lamps conforming to the requirements of this document may also be used on vehicles less than 2032 mm in overall width
Heavy Duty Lighting Standards Committee
In this work, we evaluated computational fluid dynamics (CFD) methods for predicting the design trends in flow around a mass-production luxury sport utility vehicle (SUV) subjected to incremental design changes via spoiler and underbody combinations. We compared Reynolds-averaged Navier–Stokes (RANS) using several turbulence models and a delayed detached eddy simulation (DDES) to experimental measurements from a 40% scale wind tunnel test model at matched full-scale Reynolds number. Regardless of turbulence model, RANS was unable to consistently reproduce the design trends in drag from wind tunnel data. This inability of RANS to reproduce the drag trends stemmed from inaccurate base pressure predictions for each vehicle configuration brought on by highly separated flow within the vehicle wake. When taking A-B design trends, many of these errors compounded together to form design trends that did not reflect those measured in experiments. On the other hand, DDES proved to be more
Aultman, MatthewDisotell, KevinDuan, LianMetka, Matthew
ABSTRACT Corrosion damage to military ground vehicles costs the U.S. Army around $1.6B per year. A large part of that cost is related to keeping vehicles like the Stryker at their full fighting capability. Corrosion damage has been a common finding on Stryker vehicles and even light corrosion damage, which often reaches 10% of the body thickness or more, can degrade its armor protection rating and require replacement. Recently, cold spray deposition has been shown to be capable of restoring the full ballistic resistance of corrosion damaged high hard steel armor panels. These repairs can be done on-vehicle in depot facilities, using mobile high-pressure cold spray systems. This repair capability can reduce the number of entire side, roof, and floor panels that need to be cut out and re-welded in, which is the only currently approved repair operation for corrosion damage that exceeds allowable depths. Citation: V.K. Champagne, C.A. Widener, A.T. Nardi, G.D. Ferguson, “Structural Repair
Champagne, Victor K.Widener, Christian A.Nardi, Aaron T.Ferguson, Gehn D.
ABSTRACT Two relevant materials found in ground vehicle underbody armor/hull designs are Aluminum 2139-T8 and RHA Steel (Class I). These are 2 very important materials that need a thorough understanding of their high-strain rate behavior. The Johnson-Cook Deformation (JC-D) model at this time is the most preferred constitutive material model to utilize for high-strain (large deformation) blast simulations. The JC-D Model contains five empirically-based input parameters which can be determined traditionally through a series of uniaxial laboratory tests where each target parameter is isolated, while the remaining parameters are held constant. There are many criticisms and problems with this approach. The objective of this two part paper is to present and adopt a more accurate approach with less criticism to the determination of these five input parameters through both a sensitivity study to determine which input parameters are the most sensitive to a particular chosen response which in
Hause, TerrySheng, Jianping
ABSTRACT Over the past several years, the rate of advancements in modern computer hardware and graphics computing capabilities has increased exponentially and provided unprecedented opportunities within the Modeling and Simulation community to increase the visual fidelity and quality in new Image Generators (IGs). As a result, IG vendors are continuously reevaluating the best way to make use of these new performance improvements. Some vendors have chosen to increase the resolution of the environment by displaying higher resolution imagery from disk while other vendors have chosen to increase the number of polygons that are capable of being presented in the scene while maintaining 60Hz. While all of these approaches use the latest hardware technology to improve the quality of the simulated environment in the IG, the authors of this paper have chosen to focus on a different approach; to improve the accuracy and realism of the simulated environment. To accomplish this, the authors have
Kuehne, BobHebert, KennyChladny, Brett
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
Kang., JianLiedke, MarkMason, James
ABSTRACT In this paper, we present Pegasus Transforming UAV/UGV Hybrid Vehicle, a unique, transformable UAS/UGV that is particularly well-suited for missions. The combination of flight and ground modalities allows Pegasus to fly to location, automatically transform into a ground vehicle, reposition, and quietly approach a target; or, Pegasus can land and “perch” for long durations, allowing for the maintenance of the custody trail and long ISR missions or emplace sensors particular for a specific mission. The sequential use of aerial and ground capabilities in this platform provides the reach usually lacking in these missions. The Pegasus platform was developed with DTRA/ARDEC funding in support of specialized missions where these functionalities are needed. Robotic Research, LLC has developed the system from the ground up, including: mechanical, electrical, and software designs (without using foreign-made parts). The current system is shown in Figure 2. The system already has obstacle
Lacaze, Alberto
ABSTRACT One of the main thrusts in current Army Science & Technology (S&T) activities is the development of occupant-centric vehicle structures that make the operation of the vehicle both comfortable and safe for the soldiers. Furthermore, a lighter weight vehicle structure is an enabling factor for faster transport, higher mobility, greater fuel conservation, higher payload, and a reduced ground footprint of supporting forces. Therefore, a key design challenge is to develop lightweight occupant-centric vehicle structures that can provide high levels of protection against explosive threats. In this paper, concepts for using materials, damping and other mechanisms to design structures with unique dynamic characteristics for mitigating blast loads are investigated. The Dynamic Response Index (DRI) metric [1] is employed as an occupant injury measure for determining the effectiveness of the each blast mitigation configuration that is considered. A model of the TARDEC Generic V-Hull
Jiang, WeiranVlahopoulos, NickolasCastanier, Matthew P.Thyagarajan, RaviMohammad, Syed
ABSTRACT Presented are two designs for compact, low-profile UGVs with high cross-country mobility, intended for underbody operations with heavy manned vehicles. These UGVs are designed to remotely detect and assess combat damage incurred during combat operations, and analyze wear, leaks, and cracks, without the need for a human technician to be exposed to enemy fire, allowing crews to rapidly assess the conditions of their vehicles. Since robots required for underbody inspection would necessarily maintain a low, compact profile, they could also perform effective last-mile resupply in a contested environment, their small size allowing them to hide behind terrain and battlefield debris much more effectively than a heavy logistics robot. Naturally, a robotic vehicle that is capable of rapid underbody inspection of friendly vehicles or last-mile resupply could also be easily adapted as a combat platform to be used against enemy vehicles. Citation: A. Washington, et al., “Expendable Low
Washington, AnastasyaStempien, AndrewSchouster, RyanWilson, DrewRead, CallumSvoboda, GarretBurton, JaredPendergrass, JacobYoung, FreddieBennett, JacobSapunkov, Oleg B.
ABSTRACT Since the development of combat vehicles for military use, such as tanks, infantry carriers, gun transports, etc. the main approach has been a monolithic structure that has been described as monocoque. This approach has been the standard–bearer since the inception of modern combat vehicles. Since the end of the Cold War, the world has become a much more “Multi–Polar” world. The U.S. is not locked in a static, monotonic engagement against the Soviet Union and its allies. The nature of the threat has changed. The U.S. Army is looking to make its Combat Vehicle fleet lighter and more adaptable to new technology and changing environments. By doing so the U.S. will be better able to project forces where they are needed. Lighter weight means more flexibility in transportation of equipment to various locations. In addition, the U.S. Army will be better able to deploy forces that have the latest and/or the most desirable protection required for the specific engagement they may
Hodges, ScottOstberg, Donald
ABSTRACT A time-accurate multibody dynamics model of the suspension system of a tracked vehicle is experimentally validated using a full-scale tracked-vehicle on an N-post motion simulator. The experiments consist of harmonic excitations at various amplitudes and frequencies and ramp excitations of the vehicle road-wheels (without the track), with each road wheel under one linear actuator of the N-post motion simulator. A high-fidelity multibody dynamics model of the vehicle along with the N-post motion simulator is constructed. The multibody dynamics model consists of rigid bodies, joints, rotational springs (that include non-linear rotational stiffness, damping and friction), actuators and contact surfaces. The rigid bodies rotational equations of motion are written in a body-fixed frame with the total rigid-body rotation matrix updated each time step using incremental rotations. Connection points on the rigid bodies are used to define joints between the bodies including revolute
Wasfy, Tamer M.O’Kins, JamesRyan, David
ABSTRACT This paper will discuss trends in compatibility issues between radio systems and Tactical Vehicle on-board systems which have been identified as potential interference sources and discuss electromagnetic compatibility (EMC) between co-located radio systems. All Tactical vehicles have electronic systems which come as part of the base vehicle, such as lights, air-conditioners, wind shield wipers, etc. all of which have the potential to disrupt communications. To further complicate the radio frequency environment today’s tactical vehicles are being outfitted with new sophisticated technology such as programmable communications systems, sensor systems and remote weapon stations. The new systems are complex and are subject to emitting and absorbing electromagnetic radiation which can severely degrade radio system performance and cause inadvertent electromagnetic fratricide
Busayadilok, TanyaBohn, Frank A.
ABSTRACT The foundation of the theory of functionally graded plates with simply supported edges, under a Friedlander explosive air-blast, are developed within the classical plate theory (CPT). Within the development of the theory, the two constituent phases, ceramic and metal, vary across the wall thickness according to a prescribed power law. The theory includes the geometrical nonlinearities, the dynamic effects, compressive tensile edge loadings, the damping effects, and thermal effects. The static and dynamic solutions are developed leveraging the use of a stress potential with the Extended-Galerkin method and the Runge-Kutta method. Validations with simpler cases within the specialized literature are shown. The analysis focuses on how to alleviate the effects of large deformations through proper material selection and the proper gradation of the constituent phases or materials
Hause, Terry
ABSTRACT At the request of the US Army’s Tank Automotive Command (TACOM) a device was built to measure the suspension parameters of any military wheeled vehicle. This is part of an ongoing effort to model and predict vehicle dynamic behavior. The new machine is called the Suspension Parameter Identification and Evaluation Rig (SPIdER) and has a capacity intended to cover all of the military’s wheeled vehicles. The machine operates by holding the vehicle body nominally fixed while hydraulic cylinders move an “axle frame” in bounce or roll under each axle being tested. Up to two axles may be tested at once. Forces at the tires and motions of the wheel centers in three dimensions and two angles are measured. Other motions of the suspension and the minimal motions of the vehicle body are measured. For steer axles the steering ratio, Ackerman steer characteristics, and kingpin orientation are measured
Andreatta, DaleHeydinger, GarySidhu, AnmolBixel, RonaldKurec, AleksanderSingh, AmandeepBaseski, IgorSkorupa, Thomas
ABSTRACT This paper reviews the Army Generic Hull [1-5] as a vital developmental tool for underbody blast modeling and simulation applications. Since 2010, it has been used extensively to help calibrate and validate various numerical software codes and methodologies. These are being used extensively today in the development of underbody armor, as well as mine blast subsystems such as seats, to protect both military vehicles and their occupants. In the absence of easily shareable information in this domain due to data classification, this specially formulated product is a valuable part of any toolset for underbody blast development and product design. Citation: K. Kulkarni, S. Kankanalapalli, V. Babu, J. Ramalingam, R. Thyagarajan, “The Army Generic Hull As A Vital Developmental Tool For Underbody Blast Applications,” In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 16-18, 2022
Kulkarni, KumarKankanalapalli, SanjayBabu, VenkateshRamalingam, JaiThyagarajan, Ravi
ABSTRACT Structural optimization efforts for blast mitigation seek to counteract the damaging effects of an impulsive threat on critical components of vehicles and to protect the lives of the crew and occupants. The objective of this investigation is to develop a novel optimization tool that simultaneously accounts for both energy dissipating properties of a shaped hull and the assembly constraints of such a component to the vehicle system. The resulting hull design is shown to reduce the blast loading imparted on the vehicle structure. Component attachment locations are shown to influence the major deformation modes of the target and the final hull design
Tan, HuadeGoetz, JohnTovar, AndrésRenaud, John E.
Abstract RedRAVEN is a pioneered autonomous robot utilizing the innovative Linked-Bogie dynamic frame, which minimizes platform tilt and movement, and improves traction while maintaining all the vehicle’s wheels in contact with uneven surfaces at all times. Its unique platform design makes the robot extremely maneuverable since it allows the vehicle’s horizontal center of gravity to line up with the center of its differential-drive axle. Where conventional differential-drive vehicles use one or more caster wheels either in front or in the rear of the driving axle to balance the vehicle’s platform, the Linked-Bogie design utilizes caster wheels both in the front and in the rear of the driving axle. Without using any springs or shock absorbers, the dynamic frame allows for compensation of uneven surfaces by allowing each wheel to move independently. The compact and lightweight ground vehicle also features a driving-wheel neutralizing mechanism, a rigid aluminum frame, and a translucent
Mekhtarian, AraHorvath, JosephLin, C.T.
ABSTRACT The primary focus of this effort is to evaluate the roof liner technology’s ability to reduce the head injury criteria (HIC) and head acceleration to mitigate vertical impact related injures to mounted crew injures which may occur during top and bottom threat events. In an effort to reduce the likelihood of head injury during top and bottom threat attacks, an adequate roof liner is needed to reduce the force exerted on the solider. The roof liners were able to pass all system level tests. The successful system level testing confirmed the blast mat technology’s TRL-6 recommendation. Citation: J. Klima, “Developing Performance and Operating Requirements for Energy Attenuating (EA) Roof Liner for all U.S. Army Military Vehicles”, In Proceedings of the Ground Vehicle Systems Engineering and Technology Symposium (GVSETS), NDIA, Novi, MI, Aug. 10-12, 2021
Klima, Julie
ABSTRACT The CAMEL program focused on force protection and demonstrated the possibility to protect occupants through higher underbelly blast levels than normally or previously observed. This required a holistic vehicle systems engineering approach to mitigate blast injuries that both optimized existing systems as well as developed new technologies. The result was zero injury to all occupants as assessed by 5th, 50th, and 95th percentile encumbered ATDs during survivability blast testing. Twelve full scale objective-level blast tests were performed on over seventy fully-instrumented ATDs without a single lower-extremity injury. The lower limb protection was provided by an isolated floor system. This system was developed from the ground-up and occupant-out during the CAMEL program. This paper chronicles the CAMEL floor system’s creation, design, testing, and development process
Kwiatkowski, KevinWatson, ChristopherKorson, Chantelle
ABSTRACT Automatic guided vehicles (AGV) have made big inroads in the automation of assembly plants and warehouse operations. There are thousands of AGV units in operation at OEM supplier and service facilities worldwide in virtually every major manufacturing and distribution sector. Although today’s AGV systems can be reconfigured and adapted to meet changes in operation and need, their adaptability is often limited because of inadequacies in current systems. This paper describes a wireless navigated (WN) omni-directional (OD) autonomous guided vehicle (AGV) that incorporates three technical innovations that address the shortfalls. The AGV features consist of: 1) A newly developed integrated wireless navigation technology to allow rapid rerouting of navigation pathways; 2) Omnidirectional wheels to move independently in different directions; 3) Modular space frame construction to conveniently resize and reshape the AGV platform. It includes an overview of the AGVs technical features
Cheok, Ka CRadovnikovich, MichoFleck, PaulHallenbeck, KevinGrzebyk, SteveVanneste, JerryLudwig, WolfgangGarner, Robert
ABSTRACT V-shaped hulls for vehicles, to mitigate buried blast loads, are typically formed by bending plate. Such an approach was carried out in fabricating small test articles and testing them with buried-explosive blast load in Southwest Research Institute’s (SwRI) Landmine Test Fixture. During the experiments, detailed time dependent deflections were recorded over a wide area of the test article surface using the Dynamic Deformation Instrumentation System (DDIS). This information allowed detailed comparison with numerical simulations that were performed with LS-DYNA. Though in general there is good agreement on the deflection, in the specific location of the bends in the steel the agreement decreases in the lateral cross section. Computations performed with empirical blast loads developed by SwRI and by more computationally intensive ALE methods in LS-DYNA produced the same results. Computations performed in EPIC showed the same result. The metal plate was then bent numerically so
Walker, James D.Chocron, SidneyMoore, Thomas Z.Bradley, Joseph H.Carpenter, Alexander J.Weiss, CarlGerlach, Charles A.Grosch, Donald J.Grimm, MattBurguess, Victor W.
ABSTRACT In order to defeat under body blast events and improve crew survivability, a monocoque aluminum cab structure has been designed as a drop on solution based on the current M1151A1 (HMMWV) chassis. The structure is comprised of all 5083-H131 Aluminum alloy armor plates with various thicknesses. The structure design consists of the following new features: (1) Robust joining design utilizing interlocking ballistic joints and mechanical interlocking features, (2) unique B-pillar gusset design connects roof & floor with B-pillar & tunnel, and (3) “Double V” underbody shaping design. The TARDEC designed, integrated & built vehicle achieved no crew core body injuries for a vehicle of this weight class and demonstrated meeting the crew survivability objective when subjected to a 2X blast during the live fire underbody blast tests. These efforts help to not only baseline light tactical vehicle capabilities, but also validate the possibility of meeting aggressive blast objectives for
Lee, Chu-HwaLacap, Demetrio M.Keller, Shawn J.
ABSTRACT In order to reduce the frequency and severity of warfighter head, neck, and spine injuries associated with military vehicle underbody IED and AVL blasts, crash, and rollover, Hy-Tek Manufacturing Co. Inc. (HMC) has designed, fabricated, tested, and optimized its Vehicle Roof Inflatable Impact Bladder (VRIIB). Comprised of two (2) thin and impermeable airbags separated by semi-rigid force distribution plates; the VRIIB is designed to be mounted on the interior roof panel of military combat vehicles in a deflated state. During IED or AVL detonation, the VRIIB inflates by means of a COTS airbag inflator to provide a significant reduction in the rate at which a warfighter’s head or neck decelerates against the rigid vehicle roof panel. The VRIIB is designed to remain inflated and functional for a protracted period of time after its initial actuation in order to protect vehicle mounted warfighters from follow-on blast related roof impacts, subsequent vehicle rollover and/or vehicle
Middlebrook, DonaldJude, JohnPeck, Jason
ABSTRACT This paper focuses on the development of a lightweight, composite floating crew floor designed to withstand the severe loading requirements of an underbody blast. Energy absorbing devices decouple the floor from the surrounding vehicle structure; therefore, in the event of an underbody blast, the impulse is spread out over a longer period of time, thus reducing the loads into the floor where the crew seats are attached. The composite floor development included: characterizing candidate materials for structural and flame/smoke/toxicity characteristics, design optimization of the composite floor geometry, modeling the response of the floor assembly during a simulated underbody blast event, and manufacturing of a physical composite crew floor. Based on this effort, the composite floor was able to meet the structural requirements of the underbody blast event, while reducing weight by more than 55% compared to the baseline aluminum floor. Moreover, due to the significant reduction
Hart, RobertDwyer, BenjaminSmail, AndrewChishti, AmmarErb, DavidLopez-Anido, Roberto
ABSTRACT Microgrids have garnered attention as they facilitate the integration of distributed renewable and non-renewable energy resources and allow flexibility to connect to the grid whenever required. When power is required for temporary missions or an emergency search and rescue mission, a vehicle-borne microgrid can supply critical power needs. In this paper, a vehicle-borne mobile microgrid consisting of a diesel generator, a battery storage system and solar panels mounted on the vehicle exterior is considered, and an operational control that minimizes the total fuel consumption and the battery degradation is formulated based on model predictive control. A simulation study is carried out considering a forward operating base mission scenario where the microgrid supplies the charging power to unmanned ground and aerial vehicles deployed in the mission. The result shows that the proposed approach is robust against uncertainties associated with renewable generation and the charging
Paudel, SarojZhang, JiangfengAyalew, BeshahCastanier, MatthewSkowronska, Annette
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