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Conversion of an M52-M131A5 tractor tanker trailer into high mobility test vehicle
70
Abstracts
105.
R. C. Sugarman, N. M. lsada and E. D. Sussman. Off-road driving simulation: design for a moving base simulator. 65 pp. (Mar. 1969). A driving simulator was designed which is suitable for conducting man-in-loop off-road mobility research (ORMR). Two definition studies were carried out in the development of the simulator and are presented in this report. One study had as its objective the establishment of the specifications for a motion simulator. The feasibility of the best of several motion platform design concepts was demonstrated by the construction of a working scale model motion platform. The other study was concerned with the definition of a visual simulator, including the evaluation of the applicability of presently used techniques and the recommendation of a particular simulator concept. The O R M R simulator concept is a combination of both programmed and unprogrammed visual display sources. The programmed source, either video tape or film, allows regulation of speed along the route, but little control of the route. The unprogrammed source, provided by a model terrain board, allows both regulation of speed and control over route selection. These two display sources, when combined with a three degreeof-freedom motion platform, and a real-time computer-based vehicle dynamics model, will provide a research tool suitable for precise and relatively inexpensive investigation of a wide variety of important off-road driving problems. (U.S. Gov Res. Dev. Rep., 25.8.69, AD-6895771.
106.
D. H. Timmerman and T. H. Wu. Behaviour of dry sands under cyclic loading. J. Soil Mech. Fndns Div. ASCE, 95, SM4, Proc. Paper 6698, 1097-1112 (July 1969). The stress-strain characteristics of dry sands under cyclic loading is described. Within the range of stress and acceleration studied, the soil deformation consists primarily of shear deformation. While the volumetric compression of the soil always increases under cyclic loading, its contribution to the total strain remains small. The magnitude of the principal stress ratio, above which large strains may develop under vibration, is dependent on the confining pressure. At a low confining pressure (7 psi) this ratio is about ½ of the principal stress ratio for failure in static tests. At a higher confining pressure (20 psi), it is about ¼ of the static ratio. For foundation vibration problems, the strong influence of the confining pressure implies that a rather important size effect may arise. For two foundations of unequal size, loaded to equal unit pressure, the zone of stressed soil beneath the larger foundation would extend to a larger depth. The average confining pressure on the soil in this zone would also be greater. (Author's summary.)
107.
Twister series of 8 x 8 vehicles. Governmental affairs Inst. Washington D.C. 9 pp. (Jan. 1969)" Under development is a radically new type of 8 x 8 vehicle called the Twister. Two fourwheeled chassis, each with its engine and transmission, are linked by a pivot-yoke joint that permits articulation: the front unit is free to pitch and both units can yaw and roll relative to each other. Three vehicles are now being constructed, of which an armored version is designated XM808. (U.S. Gov. Res. Dev. Rep., 25.7.69, AD-687377).
108.
V. Wasynczuk and R. Glomb. Conversion of an M52-M 131A5 tractor tanker trailer into high mobility test vehicle. U.S. Army Report. (Aug. 1968). An M52-MI31A5 tractor/trailer tanker has been converted for high mobility, two hydraulically powered tractor axles being added to provide maximum utifisation of power, improved gradability and rim pull, even over difficult terrain. Standard M52 drive axles and suspension system were fitted on the trailer, a specially designed hydraulic-motor-driven gearcase having a ratio providing the correct speed-match when the transmission is in low/ low forward or low/low reverse. The tractor engine is the sole power supply. Simplified driver controls are incorporated. Off-the-road tests preliminary to 6000 miles of performance testing have given satisfactory results. (M.I.R.A. 1969.)
109.
J. Weber. Theoretical and experimental investigation on the similitude applicable to scale model study of the mechanical behaviour of granular materials. Annales des Ponts et Chaussees 138 (1) 25-34 (Jan./Feb. 1968). Author shows that Froude simulitude is applicable to scale-models study of mechanical behavior of granular materials if: --grains in model have same specific density as in structure, but dimensions and elasticity modulus are E times smaller than in structure (model-scale: l/X), --grains in model and in structure follow Coulomb's law. In practice, generally, same grains are used in model and in structure and these conditions are not observed. Author reviews the different factors which produce the differences (related to
Abstracts
105.
R. C. Sugarman, N. M. lsada and E. D. Sussman. Off-road driving simulation: design for a moving base simulator. 65 pp. (Mar. 1969). A driving simulator was designed which is suitable for conducting man-in-loop off-road mobility research (ORMR). Two definition studies were carried out in the development of the simulator and are presented in this report. One study had as its objective the establishment of the specifications for a motion simulator. The feasibility of the best of several motion platform design concepts was demonstrated by the construction of a working scale model motion platform. The other study was concerned with the definition of a visual simulator, including the evaluation of the applicability of presently used techniques and the recommendation of a particular simulator concept. The O R M R simulator concept is a combination of both programmed and unprogrammed visual display sources. The programmed source, either video tape or film, allows regulation of speed along the route, but little control of the route. The unprogrammed source, provided by a model terrain board, allows both regulation of speed and control over route selection. These two display sources, when combined with a three degreeof-freedom motion platform, and a real-time computer-based vehicle dynamics model, will provide a research tool suitable for precise and relatively inexpensive investigation of a wide variety of important off-road driving problems. (U.S. Gov Res. Dev. Rep., 25.8.69, AD-6895771.
106.
D. H. Timmerman and T. H. Wu. Behaviour of dry sands under cyclic loading. J. Soil Mech. Fndns Div. ASCE, 95, SM4, Proc. Paper 6698, 1097-1112 (July 1969). The stress-strain characteristics of dry sands under cyclic loading is described. Within the range of stress and acceleration studied, the soil deformation consists primarily of shear deformation. While the volumetric compression of the soil always increases under cyclic loading, its contribution to the total strain remains small. The magnitude of the principal stress ratio, above which large strains may develop under vibration, is dependent on the confining pressure. At a low confining pressure (7 psi) this ratio is about ½ of the principal stress ratio for failure in static tests. At a higher confining pressure (20 psi), it is about ¼ of the static ratio. For foundation vibration problems, the strong influence of the confining pressure implies that a rather important size effect may arise. For two foundations of unequal size, loaded to equal unit pressure, the zone of stressed soil beneath the larger foundation would extend to a larger depth. The average confining pressure on the soil in this zone would also be greater. (Author's summary.)
107.
Twister series of 8 x 8 vehicles. Governmental affairs Inst. Washington D.C. 9 pp. (Jan. 1969)" Under development is a radically new type of 8 x 8 vehicle called the Twister. Two fourwheeled chassis, each with its engine and transmission, are linked by a pivot-yoke joint that permits articulation: the front unit is free to pitch and both units can yaw and roll relative to each other. Three vehicles are now being constructed, of which an armored version is designated XM808. (U.S. Gov. Res. Dev. Rep., 25.7.69, AD-687377).
108.
V. Wasynczuk and R. Glomb. Conversion of an M52-M 131A5 tractor tanker trailer into high mobility test vehicle. U.S. Army Report. (Aug. 1968). An M52-MI31A5 tractor/trailer tanker has been converted for high mobility, two hydraulically powered tractor axles being added to provide maximum utifisation of power, improved gradability and rim pull, even over difficult terrain. Standard M52 drive axles and suspension system were fitted on the trailer, a specially designed hydraulic-motor-driven gearcase having a ratio providing the correct speed-match when the transmission is in low/ low forward or low/low reverse. The tractor engine is the sole power supply. Simplified driver controls are incorporated. Off-the-road tests preliminary to 6000 miles of performance testing have given satisfactory results. (M.I.R.A. 1969.)
109.
J. Weber. Theoretical and experimental investigation on the similitude applicable to scale model study of the mechanical behaviour of granular materials. Annales des Ponts et Chaussees 138 (1) 25-34 (Jan./Feb. 1968). Author shows that Froude simulitude is applicable to scale-models study of mechanical behavior of granular materials if: --grains in model have same specific density as in structure, but dimensions and elasticity modulus are E times smaller than in structure (model-scale: l/X), --grains in model and in structure follow Coulomb's law. In practice, generally, same grains are used in model and in structure and these conditions are not observed. Author reviews the different factors which produce the differences (related to