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Mobility testing was conducted on two HMMWVs at the U.S. Army Yuma Proving Grounds by the U.S. Army Tank-automotive Research, Development and Engineering Center (TARDEC), and Rod Millen Special Vehicles (RMSV) of Huntington Beach, California January 7-9 2003. One of the vehicles tested was a standard HMMWV and the second was a civilian 1992 Hummer with a magneto-rheological fluid (MR) semi-active suspension system that was designed and installed on the vehicle by RMSV. The purpose of the tests was to evaluate the possible performance benefits of the MR fluid suspension system. Ride quality performance was quantified over three separate cross-country courses. Each vehicle's driver limited speed was also measured over discrete half-round obstacles of 4, 6, and 8-inch heights. Vehicle maneuverability was also evaluated by testing over a lane-change course and a slalom course at a variety of vehicle speeds. Limited vehicle roll down tests were also conducted to get a comparison of the rolling resistance of the two vehicles.

Princeton University has constructed a specialized wind tunnel, the Princeton/ONR High Reynolds number Testing Facility (HRTF) to be used for aero/bydrodynamic testing of submersible shapes. The facility is capable of operation at very high pressures, up to around 230 atmospheres, with relatively low test velocities. Old Dominion University is responsible for the design and commissioning of a Magnetic Suspension and Balance System (MSBS) for use with the HRTF. The design task encompasses configuration definition, detail design and documentation. Initial commissioning was undertaken at NASA Langley Research Center, with subsequent relocation to Princeton and installation in the HRTF.

PS-MMT nanocomposites were prepared via suspension free radical polymerization of styrene in the dispersed organo-MMT. The results of XRD and TEM indicated that exfoliated nanocomposites were achieved. The effect of surfactants on the properties of then synthesized nanocomposites was studied. It is found that PS_MMT nanocomposite with 5% wt% of organo-MMT gave the greatest improvement in the thermal stability, and PS-MMT nanocomposites with 7.5% of organo- MMT showed the greatest improvement in mechanical properties, comparing with that of pure PS in our experimental conditions. The alkyl chain length of surfactant used in fabricating organo-MMT affects the synthesized PS nanocomposites, the longer the alkyl chain length that the surfactant possesses, the higher glass transition temperature PS nanocomposite. It is found that the organoclay in the nanocomposites seems to play a dual role: (a) as nanofiller leading to the increase of storage modulus and (b) as plasticizer leading to the decrease of storage modulus.

This project developed and demonstrated design and fabrication technologies required to enable mass production of MEMS micromovers and electrostatic motors required to actuate these structures, including suspension systems of unprecedented high aspect ration by Hewlett Packard. Single and multiple level electrical interconnect fabrication techniques were developed and refined by Cornell University. A technique to fabricate large arrays of field emission tips was developed by U.C. Davis., The original document contains color images.

This research examines the Federal agency source selection process within Federal contracting agencies by conducting an analysis of Federal Head Contract Authority (HCA) decisions to override the required statutory stay of contract award and performance, in accordance with the Competition in Contracting Act (CICA) of 1984, resulting from bid protests. This thesis includes an analysis of the Government Accounting Office (GAO) Comptroller General of the United States findings and independent research data with respect to Federal agency decisions concerning suspension of contract award and continued performance resulting from pre-award and post-award bid protests. This research evaluates the effectiveness of the Federal agency source selection process via an analysis of HCA and GAO decisions concerning suspensions of contract awards as a result of pre-award bid protests within the previous seven fiscal years. This research also evaluates HCA and GAO justifications for continued contract performance despite post-award bid protests within the previous seven fiscal years. The objectives are to determine if Federal contracting agency decisions are justified because of the source selection process being executed as designed, and to determine if agency judgments to continue performance are supporting the best needs of the Government., The original document contains color images.

This report describes the investigation of the modeling and construction of low vibration mechanical compressors, such as used in cryogenic coolers. The classic 'Oxford' cryocooler has a clearance seal between the piston and the cylinder which is maintained by the use of spiral disc springs. In a typical compressor this clearance is about 12 microns, and therefore the spring suspension system must have a linearity of no more than 3 or 4 microns to avoid contact. It has always been assumed that to maintain this linearity, the surfaces between which the springs are clamped must be very flat and very parallel to each other. It has also been assumed that the flatness and parallel-ness of the clamping at the inside of the spring is more important than at the outside. We investigate how the linearity of motion is dependent on the clamping conditions of the springs. Tests were carried out on a typical suspension system which was deliberately assembled between non-parallel clamping surfaces, and the linearity of the resulting motion was measured. A simple theoretical model was developed which gives good agreement with the experimental results., The original document contains color images.

The classic compromise between wheeled vehicle ride comfort and handling is well known. For off-road vehicles (as used by the military), it is very difficult to achieve a good compromise due to the fact that these vehicles are also used on highways at high speeds. Controllable suspension systems offer the possibility to change the spring and damper characteristics while the vehicle is moving, thereby adapting to different terrains and speeds. This research involved the design, development, manufacturing, modeling and testing of a two-stage, semi-active, hydro-pneumatic spring, combined with a two stage semi-active damper. This system promises to improve both the ride comfort and handling (and therefore the mobility) of military wheeled vehicles. Test results indicate that the required characteristics can be achieved, and a design study proves the feasibility of fitting the system to a vehicle. It is concluded that the proposed suspension system is feasible and that further development of the system should continue.

United States Navy SEALs (Sea, Air, Land) frequently employ high speed planing boats (HSPBs) in the performance of their missions. Operation of these vessels in normal and adverse conditions exposes personnel to severe mechanical shock. Anecdotal evidence and recent medical studies conducted by the Naval Health Research Center show a correlation between HSPB operation and chronic and acute personnel injury. Most current research focuses on short-term solutions that reduce shock at the hull-deck and deck-seat interfaces (deck padding and suspension seats, for example). The object of this thesis is to develop an Optimal Deadrise Hull (ODH) that reduces mechanical shock where it first enters the boat, at the hull-sea interface. Planing boat hydrodynamics were reviewed and the mechanical shock environment was evaluated. The ODH analysis is performed on the MkV Special Operations Craft in order to determine the effects of hull deadrise on vertical acceleration. Finally, the results of the ODH analysis are used to perform a design space study of planing hulls in order to optimize the overall design for vertical acceleration based on hull deadrise, cruise speed, and payload weight.

In this paper we present seismic signature simulations using ground vibration inputs from high-fidelity 3-D mechanical system models. Results for an M1A1 and T72 are discussed. By analyzing the simulated seismic signature data in conjunction with the spectral features associated with the vibrations of specific vehicle sprung and un-sprung components we are able to make unambiguous associations of seismic signal features with suspension elements, offering valuable insight into target classification. The development of a utility ("Tankmod") to streamline creation of DADS tracked vehicle dynamic models for generating seismic signals was reported in 2000. A model of an M1A1 tank created using Tankmod was described. During the past year, two new models were created: a T72 tank and a BMP-2 armored personnel carrier. In addition, an improved vehicle speed/steer controller was developed. The new controller maintains realistic vehicle behavior by properly limiting drive sprocket torques and sprocket rotation for skid steering. Model inputs used in seismic signature modeling are in the form of time series of ground reaction force and absolute position for each track block., See also ADM201471, Papers from the Meeting of the MSS Specialty Group on Battlefield Acoustic and Seismic Sensing, Magnetic and Electric Field Sensors (2001) Held in Applied Physics Lab, Johns Hopkins Univ, Laurel, MD on 24-26 Oct 2001. Volume 2 (Also includes 1999 and 2000 Meetings), The original document contains color images.

The primary goal of this work is to use mathematical modelling to assist in defining the operational limits of the Australian Army CH-47D Chinook when carrying mixed density slung loads. This report presents the first phase in the program: the development of a simple helicopter slung-load model for simulation and analysis of the system dynamics. General system equations of motion are obtained from the Newton-Euler equations in terms of generalized coordinates and velocities. The system is partitioned into coordinates such that the motion due to cable stretching is separated from that due to rigid-body, coupled dynamics. In the formulation used, the constraint forces appear explicitly and a solution to the resultant generalized accelerations can be determined by modelling the cable as a simple spring. An inelastic solution is also possible by nulling the stretching coordinates to obtain a relation for the suspension forces. The system equations are also extended for the multiple load case. The model is verified by imposing certain constraints in order to approximate a simple pendulum system and then comparing its behaviour with analytical results. Various configurations of the complete helicopter slung-load system, based on the CH-47B Chinook carrying standard military containers, are then examined in an investigation of the open-loop characteristics. In the investigation, several parameters such as the helicopter-load mass ratio, suspension configuration, and number of loads are varied and the resulting system modes examined. A number of simulations are also presented which demonstrate the characteristic behaviour of such systems.

Proceedings from 2001 Vehicle Technologies Symposium - Intelligent Systems for the Objective Force 29-31 May 2001 Sponsored by NDIA, The original document contains color images. Viewgraphs only.

The purpose of this study was to examine the change in load distribution characteristics associated with adding lateral stiffness elements (rods) to a rucksack. A manikin was instrumented to allow determination of the load applied to the shoulders and upper torso independent of the load applied to the hips and lower trunk. Position and mass of the payload (25 kg) was fixed at the centre of the volume of the rucksack and held constant during all testing. Results showed that this active stiffness element shifted 10% of the vertical load from the upper torso to the pelvic region with no adverse affect on other factors known to limit load carriage capacity. Lumbar shear load remained unchanged between the rod and no-rod conditions for all combinations of shoulder strap and waist belt tension. The lateral rods also provided a greater extensor moment about the medio-lateral axis at the L3-L4 level., The original document contains color images. Pres: RTO Human Factors and Medicine Panel (HFM) Specialists' Meeting, Kingston, Canada, p19-1/19-6, 27-29 Jun 2000. This article is from ADA394945 Soldier Mobility: Innovations in Load Carriage System Design and Evaluation (la Mobilite du combattant: innovations dans la conception et l'evaluation des gilets d'intervention)

Standardized objective measurements for the evaluation of load carriage include the development of a load carriage simulator, a stiffness tester, and a suspension system characteristics tester. In addition, human-based methods have been developed by which the performance of load carriage systems undergoing evaluation in standardized military activities can be assessed. The purpose of this paper is to summarize three studies that examine the correlation between these objective and human-based measures. In the first study, face validation was undertaken by comparing the outcome of measurements made in pack- based systems using a simple biomechanical model. In the second study, a direct comparison of objective measures to human based measures in a cohort of military volunteers was undertaken. In a final study, a ranking method was explored as a way of characterizing military load carriage systems., The original document contains color images. Pres: RTO Human Factors and Medicine Panel (HFM) Specialists' Meeting, Kingston, Canada,p15-1/15-12, 27-29 Jun 2000. This article is from ADA394945 Soldier Mobility: Innovations in Load Carriage System Design and Evaluation (la Mobilite du combattant: innovations dans la conception et l'evaluation des gilets d'intervention)

During fiscal years 1997 and 1998, the Weapons Analysis Branch, Ballistics and Weapons Concepts Division, Weapons and Materials Research Directorate of the U.S. Army Research Laboratory, built an engineering-level model of the unmanned ground vehicle platform used in the Office of the Secretary of Defense Demo III robotics program. The computer model was a representation of the mobile detection assessment reconnaissance system (MDARS) chassis-suspension system. The model was developed within the structure of the combat vehicle engineering simulation (CVES). This effort was undertaken to develop a simulation tool to evaluate the 'ride quality' of small robotic vehicle platforms during off-road travel. 'Ride quality' is defined as the ability of the vehicle's suspension to attenuate shock and vibration between the terrain surface and the vehicle chassis. An ensuing effort was undertaken to develop a computer model of the second generation Demo III robotic vehicle, the experimental unmanned vehicle (XUV). This model was developed with engineering parameters and data provided by the vehicle's manufacturer within the structure of CVES. A simulated ride quality comparison study was performed on the MIDARS and XUV chassis-suspension models. The two models were exercised over three different types of simulated terrain and five different speeds. The terrain types were digital representations of the Aberdeen Test Center 2-inch washboard course and 3-inch bump course and the Waterways Experimental Station (Vicksburg, Mississippi) T101 course. The data used for the comparisons were chassis pitch rates and vertical accelerations. The results showed that the XUV model provided substantial reductions in pitch rate and vertical acceleration amplitudes when compared to the MDARS model over most terrain types at all speeds., Original contains color plates: All DTIC reproductions will be in black and white.

Thermally stable polynrethanes with low flow temperatures were synthesized at fixed soft segment content (50%), and the relationship between their microstructure and linear viscoelastic properties were studied as a function of block length and block incompatibility. It was found that the materials changed from homogeneous to microphase-separated as segment length and incompatibility increased. Dynamic mechanical experiments demonstrated that unlike most di-and triblock copolymers, polyurethanes are incapable of developing long-range order due to large polydispersity in their segment length. A separate part of this report involves synthesizing novel biocidal dendrimers by converting the end groups of poly(propylene imine) dendrimers to quaternary ammonium salts. The antibacterial properties of these dendritic biocides against Escherichia coli were evaluated using a bioluminescence method. Bioluminescence studies showed that novel dendritic architecture improved the potency of quaternary ammonium compounds over 100 times against E. coli. The activity of these biocidal dendrimers against Staphylococcus aureus was characterized by suspension tests. The effectiveness of these series of dendritic biocides depended on the length of alkyl chains used in the quaternization and dendrimer size (generations). Biocides from PPI dendrimers were also shown to be more effective than those derived from Perstop hyperbranched polymers.

The problem of a two-phase dispersed medium is studied within the kinetic theory. In the case of small and undeformable spheres that have all the same radius, a model for the collision operator of the Boltzmann equation is proposed. The collisions are supposed instantaneous, binary and inelastic. The obtained collision operator allows, to prove the existence of an H theorem in several configurations according to the assumptions made about the particles and particularly in the case of a diluted suspension of weakly inelastic collisions. Because of the complexity of the non linear structure of the collision integral, the Boltzmann equation is very difficult to solve and to analyze. It is therefore interesting to introduce a BGK model equation to study qualitatively its solution. In order to be physically realistic and consistent with the assumptions related to the collisions, a collision frequency depending on the particles velocities is chosen. Moreover, the collision frequency is expected to vary strongly with the particles velocities. Taking this into account, a BGK model is written. All the basic properties of the original operator are retained., Papers from Rarefied Gas Dynamics (RGD) 22nd International Symposium held in Sydney, Australia on 9-14 July 2000. See also ADM001341 for whole conference on cd-rom.

The Aircraft Rescue and Fire Fighting (ARFF) community and U.S. Military Organizations have experienced several Emergency Response Vehicle rollover induced accidents in recent years. The Air Force has a large inventory of P-18 water tankers (194) and P-19 ARFF vehicles (399) that are subject to rollover incidents. These vehicles are expected to remain in service for at least 15 years. As a near-term solution., retrofitting the suspension system to increase stability may be the only option available at the present time. This report documents the results of testing a P-18 modified with Davis Technologies International (DTI) strut units. Phase I involved testing the P-18 in its current suspension configuration to establish a baseline set of performance data. Phase II involved retrofitting and testing the P-18 with six DTI strut units (one per wheel end). Testing of the P-18 with the DTI suspension system showed that the vehicle could be operated at increased speeds of 10-30% before loss of vehicle control was observed. In most cases the lateral acceleration required to roll the vehicle was increased to the lateral acceleration at tire slip, so the vehicle was more likely to experience a controlled loss, or slide-out, rather than actual rollover., PDF updated 23 May 2012.

This paper provides an assessment of the state-of-the-art and design considerations of missile/aircraft integration for future precision strike missile systems. Benefits of missile/aircraft integration include compatibility with a broader range of aircraft carriage platforms, unrestricted carriage envelope, safe and accurate store separation, and enhanced survivability for the aircraft platform. Technologies and design considerations are grouped into the following discussion areas: * Missile factor of safety compatibility. Assessments in this area include structural design factor of safety, carriage flight loads, and design specification of the carriage flight environment. * Missile carriage and launch compatibility. Assessments in this area include launch platform compatibility constraints, firepower, launcher alternatives, compressed carriage, and standard suspension requirements. * Survivability (missile observables/insensitive munitions) compatibility. Assessments in this area include internal carriage, reduced observable plumes, and insensitive munitions., Presented at the Systems Concepts and Integration Panel (SCI) and the Consultant and Exchange Programme of RTO in support of a Lecture Series presented on 23-24 March 2000 in Atlanta, USA, on 3-4 April 2000 in Turin, Italy, and on 6-7 April 2000 in Ankara, Turkey. This article is from ADA387602 Technologies for Future Precision Strike Missile Systems (les Technologies des futurs systemes de missiles pour frappe de precision)

The U.S. Army Corps of Engineers is developing a capability to simulate seismic signatures of moving armored vehicles. To generate vehicle specific signatures these high-fidelity simulations require vehicle-generated forces acting on the earths surface at the vehicle. We present a description of customized enhancements to commercially available dynamic analysis software known as DADS (Dynamic Analysis Design System LMS-CAE Coralville Iowa). The customizations simplify creation of a 3-D dynamics model of a tracked vehicle particularly its suspension. A GUI interface facilitates creation and layout of suspension elements the creation of the basic track block and the proper positioning of track block links at the initial configuration of the vehicle. Our first application of this modeling capability is to an Ml tank. Our output data are time histories of the track/ground forces at all points of contact between the track and the deformable soil. We present sample output from a simulation of variable speed straight-ahead driving. Simulations conducted to-date include constant and variable speed driving and cornering on high and low-friction surfaces., The original document contains color images.

Driving safety and ride comfort of cross-country vehicles can be improved with the help of a controlled spring/suspension system. The present paper describes the impact of a semiactive and partially active chassis system on the driving behaviour of a cross-country 8x8 wheeled vehicle. The mobility analysis is based on a multibody vehicle model used for simulating cross-country drives and handling. To start with, the fundamental Skyhook"-principle is used for controlling; vertical accelerations and vehicle movements are clearly reduced on rough tracks and sine wave lanes., Presented at the Specialists' Meeting of the RTO Applied Vehicle Technology Panel (AVT) held in Ottawa, Canada, 18-20 Oct 1999. This article is from ADA388195 Structural Aspects of Flexible Aircraft Control (les Aspects structuraux du controle actif et flexible des aeronefs)

Under contract DAAEO7-98-C-L020 testing was conducted at the U.S. Army Yuma Proving Grounds by the U.S. Army Tank-automotive and Armaments Command, Research, Development and Engineering Center and the University of Texas Center for Electromechanics during 8, 9, and 10 November 1999 between an active (electromechanical suspension) and passive High Mobility Multi-Purpose Wheeled Vehicle (HMMWV) to determine performance improvements. Two tests, RMS Courses and Lane Change Maneuver, produced the most complete performance results for Ride Quality and Maneuverability determination. For the Lane Change Maneuver, the active HMMWV has much less sprung mass (frame) acceleration, over 5 times reduction at higher speeds, than the passive HMMWV. For the active HMMWV, sprung mass acceleration remains mostly constant at around 0.1 g's to 55 MPH while the passive HMMWV shows noticeable increases, at times in excess of I g. For the RMS Courses, a comparison shows a 5 times reduction in absorbed power over courses 2 to 5 with the active HMMWV. The active HMMWV has much less sprung mass acceleration, over 4 times reduction at higher speeds, than the passive HMMWV. For the active HMMWV it remains mostly constant at around 0.75 g's to higher speeds while the passive HMMWV shows noticeable increases, at times in excess of 2 g's. Total peak power usage was in the range of 3 kW (RMS and Lane Change Maneuver Courses) and total peak regeneration in the range of 6 kW (RMS Courses) for the active suspension.

A low flow noise sonobuoy suspension system having a surface float, a suspension cable having a compliant portion, a bridle, a hydrophone, a mechanical cable, a terminal weight, and a drogue. The hydrophone is located within the bridle and is attached to the bridle so as to allow the hydrophone to remain roughly vertical if the bridle is tilted. The bridle is located below the surface float and is connected to the surface float by means of the suspension cable. The drogue is located below the bridle and is connected to the bridle by a mechanical cable. The drogue is connected at an attachment point on the mechanical cable such that the relative velocity of the hydrophone is negligible. The terminal weight is also attached to the mechanical cable. By means of this arrangement, both the horizontal motion noise caused by the relative velocity of the hydrophone, and the vertical motion noise caused by the surface waves are reduced.

This report describes the synthesis, thermal stability and coating of nanocrystalline oxide composites for thermal barrier coating applications. The composites consisted of alumina-zirconia and alumina-yittria stabilized zirconia. The effect of alumina and yittria content on zirconia phase stability was examined. It was found that alumina-zirconia composites underwent phase transformation upon heat treatment at 950-1100 C. A small amount of yttria additive (1%) prevented zirconia phase transformation. Addition of alumina to the yttria stabilized zirconia system suppressed grain growth below 1100 C. The yttria stabilized zirconia powders were successfully coated onto Ni substrates using electrophoretic deposition. The composition of the coating solution was systematically varied to attain the optimal suspension for coating applications.

A soft-bodied, towable, active acoustic module includes a specially formed suspension fixture and a flexible faired body enclosing an active acoustic array. The suspension fixture is a Y-shaped tube having a single forward end and two trailing ends, one for attachment of a trailing tow cable and the other for attachment of the flexible, faired body. The flexible, faired body is an elongated hydrofoil having sections which allow lateral bending. The combination of the suspension feature and lateral bending feature allows the module to be deployed and recovered through shipboard undersurface deployment tubes. A weight attached to the faired body near the lower rear end balances the body to maintain a substantially vertical position during towing. Flow steps on the lower portion of the faired body reduce lateral oscillations.

This study addressed the industrial suppliers for suspension systems and their components for tracked combat vehicles (TCVs). It contains a summary of findings by another study group that addressed suspension systems for current TCVs. It provides original research on the components and related manufacturers for adaptive or active systems in which the rate of energy storage or dissipation by the suspension system is automatically adjusted to improve the system's performance. The study concludes that although some manufacturing capabilities should be monitored, the industrial capacity to produce suspension systems for TCVs does not warrant urgent concern by the Department of Defense.

The Government Maglev System Assessment Team operated from 1991 to 1993 as part of the National Maglev Initiative. They assessed the technical viability of four U.S. Maglev system concepts, using the French TGV high speed train and the German TR07 Maglev system as assessment baselines. Maglev in general offers advantages that include high speed potential, excellent system control, high capacity, low energy consumption, low maintenance, modest land requirements, low operating costs, and ability to meet a variety of transportation missions. Further, the U.S. Maglev concepts could provide superior performance to TR07 for similar cost or similar performance for less cost. They also could achieve both lower trip times and lower energy consumption along typical U.S. routes. These advantages result generally from the use of large gap magnetic suspensions, more powerful linear synchronous motors and tilting vehicles. Innovative concepts for motors, guideways, suspension, and superconducting magnets all contribute to a potential for superior long term performance of U.S. Maglev systems compared with TGV and TR07.

A dynamic model of the Polaris Sportsman 500 All-Terrain Vehicle (ATV) was built using Dynamic Analysis and Design System (DADS) version 8.5. Aspects of the model included the front MacPherson struts and rear independent suspension. The model also allowed control over the path and speed of the vehicle using the DADS control elements. The modeling methods discussed here are general in nature and may be applied to other DADS vehicle models of similar systems. This report also provides a usefull reference source to those using this model.

The vulnerability of human eyes and sensing devices to high power laser radiation presents a critical need in both the military and private sectors for protection devices. These devices must permit normal eye and sensor functions while blocking all damaging wavelengths when subjected to high power radiation. Optical power limiting provides just such a mechanism for this type of passive protection. Optical limiting has been investigated in a number of materials with distinct nonlinear mechanisms 1. Of these materials, the most widely investigated are: (1) Organic and organometallic molecules which rely on reverse saturable absorption (RSA). The more promising RSA materials include heavy-atom-substituted phthalocyanines 2,3, porphyrins 4, and fullerenes 5. The phthalocyanines have demonstrated superiority at the most commonly investigated wavelength of 532 nm, and show optical power limiting for a range of wavelengths in the visible spectral region. Very recent studies have shown enhanced properties of fullerenes in the red and near-IR 6,7,8,9. (2) Colloidal carbon suspensions, which rely on nonlinear scattering. While they yield broadband limiting in the near-IR, carbon suspension materials are widely regarded as unsatisfactory, especially in view of the requirement that they be used in a liquid state.

The active suspension system developed for this project is based on an active damper for controlling the medium and high speed dynamics involved with vehicle body and wheel motions, and an active ride height system for controlling the low speed body motions. This type of system makes improvements over a passive system by allowing the optimal damping required for differing terrain and vehicle control requirements to be automatically set by the suspension system while the active ride height system controls the vehicle attitude without sacrificing either passenger isolation or handling. This type of system has been shown to be very competitive with fully active systems over a wide range of running conditions with lower cost, lower energy usage and improved failure modes. The vehicle properties of the Joint Tactical Electric Vehicle, which this suspension system will be implemented on, have been determined and are listed in the main body of this report. Parameters for a selection of tires which are used on this and similar vehicles have been determined for a range of tire pressures and other test conditions, some of this data is given in the appendix. Testing was also performed to determine the possibility of determining the tire deflection from tire pressure measurements. It was found that there was a correlation between the tire pressure and tire deflection although the pressure raise was small, on file order of 5 psi. Because of this relatively small pressure raise, there would be difficulties involved in filtering out other changes in pressure from temperature changes and acoustic effects which are of the same order of magnitude as the pressure raise from tire deflection., Prepared in cooperation with Rod Millen Special Vehicles, Huntington Beach, CA.

Electromechanical suspension actuators are devices intended to provide the force input called for by motor vehicle active suspension systems. Experimental active suspensions have been devised, in which hydraulic actuators provide the force input. Such systems leave much to be desired regarding safety to equipment and personnel. In addition, hydraulic actuators require an electromechanical valve to interface the electrical and hydraulic aspects of the overall system. Accordingly, electromechanical actuators are being studied as an alternative approach to active suspension design. Such actuators would provide a direct interface between electrical/electronic controls and the suspension dynamics, eliminating the need for hydraulic systems and their attendant problems of leakage and vulnerability to battle damage. The report that follows, describes the reason for studying electromechanical actuators, requirements such devices must meet, and various development programs. In addition, this report also describes various electric motor and actuator concepts that could serve as a point of departure for future electromechanical actuator development.

The presence of radionuclides. One advantage of linking the pollutants to sediment is that we can take advantage of existing work by arctic geological oceanographers, e.g., on uptake and transport processes. Sediment is incorporated into the newly forming ice cover by a process called suspension freezing. Individual ice crystals may first nucleate to the very fine grained sediment in the water column. Once formed, the ice crystals aggregate and effectively filter sediment as the flocked frazil ice moves through the water column. Further filtration is accomplished as turbid water percolates through the floating frazil ice cover. The observational evidence shows that almost all of the sediment found in first year ice is contained in the frazil layers. The uptake of pollutants into the ice depends on the presence of suspended particulate matter (SPM) in the water column.

The design and development of an aerosol generator utilizing pyrotechnically activated EMAA is subject to two principal requirements; effective total-flooding of the protected area, and safe transfer of thermal energy derived from EMAA combustion. Because EMAA's are ineffective below a threshold airborne concentration the aerosol generator design must limit the potential for trapping excessive amounts of aerosol before it can be released into the protected area. This concern is coupled with designing a reliable system for transferring relatively large amounts of heat from EMAA combustion to both aid in the effectiveness of the aerosol suspension and prevent the possibility of secondary fires. In addition, the corrosivity potential of the various EMAA formulations on different commonly-used metals and metal alloys found in military equipment was tested and evaluated.

A simulated suspended mine retrieval system is described. It snares a simulated suspended mine at sea that is comprised of an anchor, a buoy and a tether connecting the anchor and buoy. The retrieval system has a cable connected to a loop for snaring the simulated suspended mine. In operation the retrieval system is towed from a vessel and the loop passes over the mine and strikes the tether. When this happens the loop has a shackling arrangement that snares the tether and is of such a size that it cannot slip over the mine. This enables the simulated suspended mine to be hoisted upon the towing vessel.

Understanding the dynamic interaction between a magnetic levitated (Maglev) vehicle and its supporting guideway is essential in the evaluation of the performance of such a system. This interacting coupling, known as vehicle/guideway interaction (VGI), has a significant effect on system parameters such as the required magnetic suspension forces and gaps, vehicular ride quality, and guideway deflections and stresses. This report presents the VGI analyses conducted on an actual Maglev system concept definition (SCD), the American Maglev SCD, using a linear-elastic finite-element (FE) model. Particular interest was focused on the comparison of the ride quality of the vehicle, using two different suspension systems, and their effect on the guideway structure. The procedure and necessary assumptions in the modeling are discussed.

A recovery device for use from the cargo door of a helicopter hovering over a vehicle to be recovered and including a telescoping pole with an upper end secured to the helicopter floor and a lower end defining a hoop which can be manipulated around the weapon or target into a first position for securing a first noose to a first portion of the vehicle to be recovered. The snare pole is then shifted to a second position where a second noose is tightened around a second portion of the vehicle. After the nooses have been positioned about the vehicle, the crewman aboard the helicopter pulls the retainer lanyard joined to the retaining pins. This operation releases the snare pole from the helicopter. The inner pole telescopes within the outer pole, and the vehicle is held directly beneath the helicopter by the cargo hook. The pilot can then fly the helicopter upwardly to carry the vehicle clear of the water., Supersedes PAT-APPL-320 616-94, AD-D017 252.

The independent suspension on the Advanced Technology Demonstrator II (ATD- II) was tested to determine how it compares with the solid axle suspension on the current M923A1. It was found that: (1) the independent suspension weighs more than the solid axle suspension; (2) the ATD-II absorbed less power over test courses simulating real world terrain and (3) the ATD-II absorbed less power due to a shock caused by an abrupt obstacle in the terrain.

Mixed norm optimal control synthesis is used to solve a multiobjective suspension problem. The objective is to develop a controller for an active suspension system onboard a tractor semitrailer vehicle. The problem is first approached by using H2 and H infinity optimization. It is shown that by combining both techniques into one mixed norm optimization method, it is possible to exploit the strengths of each norm to provide superior performance. Two H2/H infinity designs were completed. One design concentrated on optimal performance at one design condition. The second design concentrated on providing the best performance possible at a medium load configuration, while maintaining robust stability at the extreme load configurations.

A process and medium are disclosed for the lyophilization of platelets. During lyophilization, carbohydrate-load platelets are supercooled while suspended in a buffer solution including a biocompatible polymer that serves to preserve the structure of the platelets. The supercooled platelets are then frozen at a temperature below the glass transition temperature of the suspension. A vacuum is placed on the frozen suspension to remove most of the water therefrom. Then, the temperature of the platelets is increased to the supercooled temperature while the vacuum is maintained. After being sealed under vacuum, the lyophilized platelets may be reconstituted to form viable, transfusable platelets. The reconstituted platelets have a high aggregation index, retain normal agglutination and degranulation capability, and are able to participate in clot formation.

A shock energy absorbing device provides shock protection for the riser line employed to attach an aerodynamic deceleration device to a primary body during deployment of the system into an airstream. During deployment, for example, by dropping an unopened parachute and attached load or by rocket delivery of the unopened parachute and attached load, the parachute is made to open at a desired altitude whereupon very large shock tension forces are generated which are applied to the line. In order to protect the line from failing under these forces and to reduce the requirement for a bulky, heavy line, a shock absorber is provided in the form of a block having one or more breakable web portions formed therein and through which the riser line is threaded. Upon deployment of the system into an airstream, the shock tension forces operate to fracture some or all of the breakable web portions thereby dissipating the shock energy generated during deployment and protecting the riser line from failure. (MM), Supersedes PAT-APPL-083 602-93.

The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

Munitions material can enter the environment as a result of manufacturing activities and field usage. Predictor methodologies, or biomarkers would enhance evaluation of environmental impacts. The goal of this exploratory study was to assess deoxyribonucleic acid (DNA) mutation frequency as a biomarker for munitions exposure. The approach involved, (1) the resolution of an effective repetitive sequence probe for the identification of characteristic mutations, and (2) the development of a testing media A CLONAL CELL LINE OF CARROT (Daucus carota) suspension cells. Commercially available probes demonstrated marginal resolution therefore a low-C0t library was then constructed. Three colonies from the low-C0t DNA library were screened and the DNA isolates sequenced. A suspension culture of carrot (Daucus carota) was developed. A mutation spectra experiment was initiated at a 10-mg TNT/L exposure concentration with the attempt to clone over 1500 single TNT-exposed cells. Over the following six months greater than 98% of the initially isolated cells were unable to survive and produce micro palluses. The remaining call were too few to be statistically significant and the experiment was terminated. The biomarker concept itself remains to be disapproved, but the need for large numbers of uniform clones to differentiate tme mutations suggest that more direct techniques using whole tissues need to be developed.

This project was aimed at understanding the curing of polymers using in situ fiber-optic Raman spectroscopy. In particular, the project emphasized curing at primarily glass interfaces, using chemometric analysis of Raman data obtained during curing. We have performed the first Raman study of the curing of a Polyimide using FT-Raman spectroscopy that employed statistical data determination and a comparison with DSC to demonstrate the ability of optical spectroscopic data to quantitatively determine the extent of curing. We have conducted in situ fiber-optic FT-Raman measurements of bulk polyimide polymers. Results from statistical analyses have been used to determine percent curing and stoichiometry in the polymers. Internal heat generation, transport and the effects of internal heat generation on reaction rates have been studied using fiber-optic methods. An in situ probe for fiber-optic Raman spectroscopy has been developed which is approximately the same size as a thermocouple, is inexpensive, easy to use and gives both temperature and cure information, with the percentage cure measurement having a standard error of 0.5% over the entire range of polymer curing. A polymer suspension of metal particles has been developed which is surface-enhanced Raman active, permitting the first optical study of the metal-polymer interface which has first-monolayer sensitivity in a bulk material. jg p.2

The Vehicle Dynamic Model VEHDYN 3.0, developed at the US Army Engineer Waterways Experiment Station, was used to compare selected displacements, velocities, and accelerations with field-measured quantities for both an empty and a fully loaded M977 HEMTT truck. Test conditions (detailed in Volume 1 of this series) included having the HEMTT negotiate small square-edged obstacles (0.25 -3.00 inches high) at low velocities (1.80 0.06 mph). Time history and Fast Fourier Transform comparisons are provided. The VEHDYN 3.0 model did a reasonable job at predicting the motion, especially the action of the HEMTT walking beam suspensions and overall low-frequency response. A procedure was demonstrated that takes acceleration data from low-amplitude front and rear drop tests and develops linear spring and damper response relationships for the HEMTT. (MM)

The Vehicle Dynamic Model (VEHDYN) 3.0, developed at the U.S. Army Engineer Waterways Experiment Station, was used to compare selected displacements, velocities, and accelerations with field-measured quantities for both an empty and a fully loaded M977 HEMTT truck. Test conditions (detailed in Report 1 of this series) included having the HEMTT negotiate small square-edged obstacles (0.25 - 3.00 inches high) at low velocities (1.80+ 0.06 mph). Time history and Fast Fourier Transform comparisons are provided. The VEHDYN 3.0 model did a reasonable job at predicting the motion, especially the action of the HEMTT walking beam suspensions and overall low-frequency response. A procedure was demonstrated that takes acceleration data from low-amplitude front and rear drop tests and develops linear spring and damper response relationships for the HEMTT. (MM)

The purpose of this task was to develop a fully active suspension system for a CF vehicle and to implement a variety of control schemes in order to demonstrate the benefits of this technology. An active suspension system has been developed and fitted on an Iltis 1/4 ton 4X4 military truck. The vehicle has on-board hydraulics and an electronic control system. The hydraulic system consists of a reservoir and an engine-driven pump which supplies oil (15.2 MP) to accumulators and servo-actuators at each suspension assembly. The electronic control system is made up of transducers, an A/D card, a control computer, and analog control cards. The control computer calculates set points for the actuators, based on transducer input values, according to user specified control algorithms. A disturbance rejection algorithm was developed which reads and maintains individual actuator force values at initial levels, thereby providing good ride quality. Stability was enhanced by increasing the downward force on outside wheels in a turn based on body lateral acceleration and actuator force feedback. The vehicle is capable of outperforming a passively suspended Iltis in virtually all test conditions attempted. Maximum attainable speeds increased by 11 percent in a steady-state turn, 20 percent in a slalom manoeuvre, and a speed increase in excess of 100 percent was possible while keeping driver accelerations at equivalent levels. The active suspension system does add mechanical and hydraulic complexity to the vehicle. Consideration of an active suspension system for an in-service CF vehicle must weight the performance benefits against additional acquisition and'life-cycle costs in well defined usage and mission scenarios.

A terrain previewing system has been created for the experimental active suspension vehicle that exists at Defence Research Establishment Suffield. The system employs ultrasonic transducers to measure the terrain elevation just ahead of the vehicle's front wheels. The elevation information is processed and correlated to vehicle forward speed by an on-board microcomputer. The elevation profile is then passed to the active suspension control computer so that algorithms used to control the active suspension actuators can have advance warning of bumps and dips. Preliminary results on a fabricated steel bump show that active control using preview information performs significantly better than passive suspension and measurably better than active control without preview.

The purpose of the work reported was to demonstrate the suitability of electrorheological (ER) technology for adaptive control of suspension forces on tracked and wheeled vehicles. The mechanical shear strength properties of ER fluids change in response to the application of an electric field. The change is very rapid and fully reversible. This property was used to create an automotive suspension damper whose resistive force is readily controlled by an external electrical signal. The device was applied in a semiactive suspension system for the Army's high mobility multipurpose wheeled vehicle (HMMWV). The work reported covers a range of development tasks including definition of the semiactive control algorithm, ER fluid formulation, design and fabrication of an ER damper, design of an electrical control circuit, creation of a quarter-HMMWV test stand for the simulation of ride vibrations, laboratory measurement of the ER-damped performance characteristics over a range of physically simulated operating conditions, and computer simulation of the quarter-HMMWV system. The research demonstrated that an ER damper and appropriate control circuits could out- perform the conventional hydraulic shock absorber, but that various complexities tend to impede broad application of electrorheology in automotive devices.

There is presented a sonic apparatus for degassing liquids. The apparatus includes a vessel for recciving and releasably retaining an open-top container and adapted to be closed with the container therein, transducer suspension structure positioned in the vessel, an ultrasonic transducer suspended from tbe structure and disposed in the container spaced from the walls and bottom of the container and beneath the surface of a liquid contained therein. The apparatus further includes a signal generated outside of the vessel for transmitting power to the transducer, and a vacuum pump for maintaining the vessel interior at a vacuum. (AN), Supersedes PAT-APPL-069 817-93, AD-D015 833.

The objective of the project is to establish and use an in vitro system of intact isolated cells from rodent and human tissues to develop quantitative data on the metabolism of toxic chemicals that can be used for risk assessments. The following halogenated aliphatic solvents are being studied: chloroform, 1,1, 1-trichloroethane, trichloroethylene, dicloromethane, bromochloromethane, and carbon tetrachloride. Chloroform is being used to establish the conditions with rat liver preparations for the generation of kinetic constants for metabolism, which are determined as disappearance- of the parent compound. Isolated hepatocytes and precision-cut liver slices are being compared to optimize the correspondence between the in vitro results obtained and the published in vivo data. The system developed with rat liver is now being applied to human liver incubations. The same set of halogenated solvents is being studied, and the resulting data should allow quantitative comparison of the metabolism and cytotoxicity in these species. These data will be analyzed to characterize interspecies differences in the kinetics of metabolism.