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124. The new German military vehicles
76
A BSTRACTS friction. For the tyre model in question, the terrain specified must be compatible; the terrain specified is a flat, firm surface of uniform slope with occasional obstacles. Prediction of tractor overturning about a tipping axis is based on measurement of angular movement and rate of rotation of tractor about tipping axis. Tractor instability occurs when there is sufficient kinetic energy to lill the centre of gravity to the point of static instability directly above the tipping axis defined as the line connecting the ground contact points of the two wheels which remain on the ground. Lateral tractor stability was examined for an input disturbance on one rear tyre. For cases where the tractor was on a side slope, the uphill rear wheel encountered the bump. For different simulations, forward tractor velocity, size of ground disturbance and slope of terrain were varied. The computer simulations were conducted to determine which sets of conditions resulted in lateral overturning. Time available for giving warning of or preventing overturning was of special interest. The minimum to take preventive action was 0.49 sec. In actual overturning tests, a tractor similar to that used in computer simulations was driven by remote control at uniform speed on a straight path involving the encountering, by the uphill rear wheel on a side slope, of a known ground disturbance. Tests were made at 3, 6, 10 and 12-8 m.p.h, on level ground and on a 17-deg slope for bumps 3, 6 and 9 in. high. The mathematical model predicted sideways tractor overturning for less severe conditions than those actually needed to overturn the tractor. Soil/tyre relationships need further investigation to improve agreement between simulation and experimental results. (M.I.R.A.)
122.
M. A. Makarov. The influence of physical-mechanical properties on the stress during working of soil. 11 pp. (June 1971). Tilling operations such as harrowing and planting may decrease soil pgrosity considerably. The stress distribution in the soil was determined by means of burying stress transducers in the soil. With an increase in the speed of tilling, the magnitude of stress increases. A speed increase of 7.5 times (0.58 to 4.37 m/see) was accompanied by a stress increase of 2.5 times. (Author's Summary. U.S. Gov. Res. Dev. Rep., 10.8.71, PB 200113-T.)
123.
d. Narain and P. C. Rawat. Tensile strength of compacted soils. J. Soil Mech. Fndns. Div., Proc. ASCE96, SM 6, 2185 2190 (November 1970). A moclest (nonvoluminous and nonsophisticated) experimental program, involving diametral compression and unconfined compression tests on specimens prepared from three soil types with various moisture contents, allowed the authors to obtain useful and actual information on the mech~.nical behavior of compacted soils: tensile and unconfined compressive strength values, their correlation and dependence upon moisture content and optimum compaction parameters, evidence of increasing flexibility by rise of water content. It is an opportune signal that soil tensile strength can be easily determined and need not be neglected by soil mechanics studies.
124.
G. Papenbroock. The new German military vehicles. A.T.Z. 73, No. 9, pp. 346-351 (September 1971), The development of the second generation of vehicles for the German army was governed by the following principles: ( 1) sub-assemblies must be as far as possible commercially available, (2) development for military purposes must be in accordance with the expected development in the commercial sector, (3) combination of several vehicles classes into "families", and (4) standardization of sub-assemblies and components within these f~milies. Medium-sized vehicles from 4 to 10 tons form one such family, which also comprises wheeled armoured vehicles. Five large German manufacturers of commercial vehicles formed a "joint bureau" in 1964 to develop vehicles to specifications laid down by the Ministry of Defence, Daimler-Benz remained outside this group, continuing their development independently, Prototypes were presented to the army in 1968 and tested during the following two years. It has now been decided that the consortium shall be responsible for unarmoured vehicles, powered by Deutz engines, and Daimler-Benz for armoured vehicles. Examples of this new generation of highly standardized military vehicles are shown and the types of engines, transmissions, steering systems and bodies described. All engines are turbocharged and of multi-fuel design. The Daimler-Benz vehicles are powered by water-cooled V-8 and V-10 engines of the new "OM 400" series. The Deutz engines are air-cooled V-8, V-10 and V-12 designs belonging to the "F-L 413" series. The engines are so designed that the unarmoured vehicles can be equipped either with air-cooled or water-cooled engines. Rims and tyres are of one standard size. All trucks are of the forward-control type, and body types are
ABSTRACTS
77
interchangeable. Most components are identical to parts used in heavy commercial vehicles. The armoured vehicles, comprising patrol cars and personnel carriers, are amphibian and have all-wheel drive. All six firms have now decided to co-operate in the scheme to provide medium-sized military vehicles at an estimated cost to the government of 4000 million DM. (M.I.R.A.) 125.
Pittsburgh University Staff. 4000-1b-capacity rough-terrain fork lift truck (December 1967). The Technical Information Report describes a 4000-1b-capacity rough-terrain forklift truck that is powered by an 85-h.p. compression-ignition engine. Its 48-in. dia., 20-in. wide highflotation tires, low weight of 8500 lb, center-articulated chassis, and pivot-frame power steering make the vehicle suitable for operation on rough terrain, in mud, in sand, in snow, and on slopes. Its maximum speed is 35 m.p.h. A simple crane kit is provided for loading and unloading high-sided cargo vehicles for which forks cannot be used. The forklift truck is 17 ft 4 in. long, 6 ft 8 in. wide, and 8 ft 6 in. high. For transportation purposes, the length can be reduced to 14 ft 1 in. and the height to 6 ft. (Author's Summary. U.S. Gov. Res. Dev. Rep., 25.7.71, AD-826335.)
126.
Pittsburgh University Staff. 16-ton 6 × 6 Conex transporter. 12 pp. (January 1968). This Technical Information Report describes a 16-ton 6 x 6 cross-country transporter that loads and unloads itself with as many as three fully loaded Conex containers weighing a total of 32,000 lb, transports the load over sandy or rough terrain having slopes up to 40 per cent, and fords streams 4 ft deep. The transporter consists of an articulated-steering two-wheel prime mover powered by a 240-hp commercial diesel engine and a 4-wheel trailer with a hydraulic-assist drive. It is equipped with a hydraulic-powered bed-tilting mechanism and winches. This 44,000-1b vehicle is 40.7 ft long, 9.7 ft wide, and 11.8 ft high (to the top of the Conex containers). Its turning radius is only 41 It, which makes it easy to maneuver through cluttered beach areas. Two experimental models are undergoing user tests in Vietnam. Following user evaluation of the equipment, the design changes requested will be made prior to the fabrication of prototype models for engineering and service tests. (Author's Summary. U.S. Gov. Res. Dev. Rep., 25.7.71, AD-827780.)
127.
I. F. Popov. Influence of the tip angle of soil working wedges and cutting edges of cultivator sweeps in agriculture. 8 pp. (May 1971). Studies were conducted with simple wedges in a soil bin. Soil resistance to the wedge was a minimum when the tip angle of a two-sided wedge 2Beta was 60 deg. (Author's Summary. U.S. Gov. Res. Dev. Rep., 10.8.71, PB-200112-T.)
128.
T. Ramamurthy. A universal triaxial apparatus (in English). J. Soil Mech. Fndn. Engng. 9, 3, 251-269 (July 1970). Author describes a universal triaxial apparatus capable of imparting three differing orthogonal direct stresses to a cubical specimen (8.6 cm). Vertical stresses are applied through specially designed lubricated end-plates with vertical force measured by conventional proving ring. Specimen is enclosed in rubber membrane sealed to horizontal end-plates, and pore-pressures are measured at base of cube. Lateral pressures are applied through system of fluid-filled bellows in metallic guides with soft rubber inserts taking up effects of discontinuity at vertical edges and strains measured directly by thin probes through the bellows. Use of flexible bellows to apply lateral stresses appears to have introduced problems, since author refers to bulging of specimen at mid-height. Although author observed only minor constraint along edges, it is possible that edge-effects in this type of triaxial apparatus could significantly affect results. However, development of this apparatus represents useful advance in technology of soil testing. (Appl. Mech. Rev.)
129.
H. F. Sehuitz. Testing of high water content cohesive soils using thin walled test cells. 72 pp. (March 1971). The concepts associated with the field of soil mechanics are now being applied to marine sediments. Because of the more complex nature of the mixture of fine mineral particles and seawater, some of these concepts do not always appear overly applicable. This is particularly true with regard to the deep-sea clays. In view of their often very high water contents, a liquid behavior might well be assumed for many marine clays. The analytical methods of fluid mechanics do not satisfactorily explain the low strengths that are found in these soils. Thin-
A BSTRACTS friction. For the tyre model in question, the terrain specified must be compatible; the terrain specified is a flat, firm surface of uniform slope with occasional obstacles. Prediction of tractor overturning about a tipping axis is based on measurement of angular movement and rate of rotation of tractor about tipping axis. Tractor instability occurs when there is sufficient kinetic energy to lill the centre of gravity to the point of static instability directly above the tipping axis defined as the line connecting the ground contact points of the two wheels which remain on the ground. Lateral tractor stability was examined for an input disturbance on one rear tyre. For cases where the tractor was on a side slope, the uphill rear wheel encountered the bump. For different simulations, forward tractor velocity, size of ground disturbance and slope of terrain were varied. The computer simulations were conducted to determine which sets of conditions resulted in lateral overturning. Time available for giving warning of or preventing overturning was of special interest. The minimum to take preventive action was 0.49 sec. In actual overturning tests, a tractor similar to that used in computer simulations was driven by remote control at uniform speed on a straight path involving the encountering, by the uphill rear wheel on a side slope, of a known ground disturbance. Tests were made at 3, 6, 10 and 12-8 m.p.h, on level ground and on a 17-deg slope for bumps 3, 6 and 9 in. high. The mathematical model predicted sideways tractor overturning for less severe conditions than those actually needed to overturn the tractor. Soil/tyre relationships need further investigation to improve agreement between simulation and experimental results. (M.I.R.A.)
122.
M. A. Makarov. The influence of physical-mechanical properties on the stress during working of soil. 11 pp. (June 1971). Tilling operations such as harrowing and planting may decrease soil pgrosity considerably. The stress distribution in the soil was determined by means of burying stress transducers in the soil. With an increase in the speed of tilling, the magnitude of stress increases. A speed increase of 7.5 times (0.58 to 4.37 m/see) was accompanied by a stress increase of 2.5 times. (Author's Summary. U.S. Gov. Res. Dev. Rep., 10.8.71, PB 200113-T.)
123.
d. Narain and P. C. Rawat. Tensile strength of compacted soils. J. Soil Mech. Fndns. Div., Proc. ASCE96, SM 6, 2185 2190 (November 1970). A moclest (nonvoluminous and nonsophisticated) experimental program, involving diametral compression and unconfined compression tests on specimens prepared from three soil types with various moisture contents, allowed the authors to obtain useful and actual information on the mech~.nical behavior of compacted soils: tensile and unconfined compressive strength values, their correlation and dependence upon moisture content and optimum compaction parameters, evidence of increasing flexibility by rise of water content. It is an opportune signal that soil tensile strength can be easily determined and need not be neglected by soil mechanics studies.
124.
G. Papenbroock. The new German military vehicles. A.T.Z. 73, No. 9, pp. 346-351 (September 1971), The development of the second generation of vehicles for the German army was governed by the following principles: ( 1) sub-assemblies must be as far as possible commercially available, (2) development for military purposes must be in accordance with the expected development in the commercial sector, (3) combination of several vehicles classes into "families", and (4) standardization of sub-assemblies and components within these f~milies. Medium-sized vehicles from 4 to 10 tons form one such family, which also comprises wheeled armoured vehicles. Five large German manufacturers of commercial vehicles formed a "joint bureau" in 1964 to develop vehicles to specifications laid down by the Ministry of Defence, Daimler-Benz remained outside this group, continuing their development independently, Prototypes were presented to the army in 1968 and tested during the following two years. It has now been decided that the consortium shall be responsible for unarmoured vehicles, powered by Deutz engines, and Daimler-Benz for armoured vehicles. Examples of this new generation of highly standardized military vehicles are shown and the types of engines, transmissions, steering systems and bodies described. All engines are turbocharged and of multi-fuel design. The Daimler-Benz vehicles are powered by water-cooled V-8 and V-10 engines of the new "OM 400" series. The Deutz engines are air-cooled V-8, V-10 and V-12 designs belonging to the "F-L 413" series. The engines are so designed that the unarmoured vehicles can be equipped either with air-cooled or water-cooled engines. Rims and tyres are of one standard size. All trucks are of the forward-control type, and body types are
ABSTRACTS
77
interchangeable. Most components are identical to parts used in heavy commercial vehicles. The armoured vehicles, comprising patrol cars and personnel carriers, are amphibian and have all-wheel drive. All six firms have now decided to co-operate in the scheme to provide medium-sized military vehicles at an estimated cost to the government of 4000 million DM. (M.I.R.A.) 125.
Pittsburgh University Staff. 4000-1b-capacity rough-terrain fork lift truck (December 1967). The Technical Information Report describes a 4000-1b-capacity rough-terrain forklift truck that is powered by an 85-h.p. compression-ignition engine. Its 48-in. dia., 20-in. wide highflotation tires, low weight of 8500 lb, center-articulated chassis, and pivot-frame power steering make the vehicle suitable for operation on rough terrain, in mud, in sand, in snow, and on slopes. Its maximum speed is 35 m.p.h. A simple crane kit is provided for loading and unloading high-sided cargo vehicles for which forks cannot be used. The forklift truck is 17 ft 4 in. long, 6 ft 8 in. wide, and 8 ft 6 in. high. For transportation purposes, the length can be reduced to 14 ft 1 in. and the height to 6 ft. (Author's Summary. U.S. Gov. Res. Dev. Rep., 25.7.71, AD-826335.)
126.
Pittsburgh University Staff. 16-ton 6 × 6 Conex transporter. 12 pp. (January 1968). This Technical Information Report describes a 16-ton 6 x 6 cross-country transporter that loads and unloads itself with as many as three fully loaded Conex containers weighing a total of 32,000 lb, transports the load over sandy or rough terrain having slopes up to 40 per cent, and fords streams 4 ft deep. The transporter consists of an articulated-steering two-wheel prime mover powered by a 240-hp commercial diesel engine and a 4-wheel trailer with a hydraulic-assist drive. It is equipped with a hydraulic-powered bed-tilting mechanism and winches. This 44,000-1b vehicle is 40.7 ft long, 9.7 ft wide, and 11.8 ft high (to the top of the Conex containers). Its turning radius is only 41 It, which makes it easy to maneuver through cluttered beach areas. Two experimental models are undergoing user tests in Vietnam. Following user evaluation of the equipment, the design changes requested will be made prior to the fabrication of prototype models for engineering and service tests. (Author's Summary. U.S. Gov. Res. Dev. Rep., 25.7.71, AD-827780.)
127.
I. F. Popov. Influence of the tip angle of soil working wedges and cutting edges of cultivator sweeps in agriculture. 8 pp. (May 1971). Studies were conducted with simple wedges in a soil bin. Soil resistance to the wedge was a minimum when the tip angle of a two-sided wedge 2Beta was 60 deg. (Author's Summary. U.S. Gov. Res. Dev. Rep., 10.8.71, PB-200112-T.)
128.
T. Ramamurthy. A universal triaxial apparatus (in English). J. Soil Mech. Fndn. Engng. 9, 3, 251-269 (July 1970). Author describes a universal triaxial apparatus capable of imparting three differing orthogonal direct stresses to a cubical specimen (8.6 cm). Vertical stresses are applied through specially designed lubricated end-plates with vertical force measured by conventional proving ring. Specimen is enclosed in rubber membrane sealed to horizontal end-plates, and pore-pressures are measured at base of cube. Lateral pressures are applied through system of fluid-filled bellows in metallic guides with soft rubber inserts taking up effects of discontinuity at vertical edges and strains measured directly by thin probes through the bellows. Use of flexible bellows to apply lateral stresses appears to have introduced problems, since author refers to bulging of specimen at mid-height. Although author observed only minor constraint along edges, it is possible that edge-effects in this type of triaxial apparatus could significantly affect results. However, development of this apparatus represents useful advance in technology of soil testing. (Appl. Mech. Rev.)
129.
H. F. Sehuitz. Testing of high water content cohesive soils using thin walled test cells. 72 pp. (March 1971). The concepts associated with the field of soil mechanics are now being applied to marine sediments. Because of the more complex nature of the mixture of fine mineral particles and seawater, some of these concepts do not always appear overly applicable. This is particularly true with regard to the deep-sea clays. In view of their often very high water contents, a liquid behavior might well be assumed for many marine clays. The analytical methods of fluid mechanics do not satisfactorily explain the low strengths that are found in these soils. Thin-