Accession Number : ADA039974
Title : Development of a Mathematical Model for the Prediction of the Off-Road Performance of 4x4 Vehicles
Descriptive Note : Final rept.
Corporate Author : GRUMMAN AEROSPACE CORP BETHPAGE NY RESEARCH DEPT
Personal Author(s) : Karafiath, Leslie L
Report Date : Jan 1977
Pagination or Media Count : 55
Abstract : A mathematical model of 4x4 off-road vehicles has been developed for the estimation of vehicle performance. The model uses the pneumatic-tire soil interaction models developed earlier for driven and towed tires and incorporates these as submodels in the vehicle performance model. Vehicle-soil interactions, such as redistribution of axle weights, due to the slope angle and applied torque, and effect of compaction by the lead wheel are taken into account. The effect on various torque transfer mechanisms between the axles is also considered. The computer program for the vehicle performance model has been prepared as a subroutine with suitable arguments for use in the AMC Mobility Model. The vehicle performance model can be used with any soil, the strength of which can be characterized by its Coulomb strength parameters. A braked tire- soil interaction model has also been developed for the estimation of the braking force that the vehicle can develop under various soil conditions. A new method of analysis of the variation of cone penetration resistance with depth has been developed. In this method incremental penetration is analyzed by assuming that the stress state in the soil produced by the previous increment remains 'locked in.' Cone pentration resistance profiles can be converted to Coulomb strength parameters by this method using a trial and error procedure.
Descriptors : *TRUCKS , COMPUTER PROGRAMS , MATHEMATICAL MODELS , ANGLES , MOBILITY , INTERACTIONS , PERFORMANCE(ENGINEERING) , SAND , TERRAIN , SOIL MECHANICS , STRENGTH(MECHANICS) , ALIGNMENT , SOILS , PENETRATION , PROFILES , MATHEMATICAL PREDICTION , WHEELS , CLAY , TIRES , OFFROAD TRAFFIC , BRAKING , VEHICLE BRAKES , VEHICLE CHASSIS COMPONENTS , TRAFFICABILITY
Subject Categories : Surface Transportation and Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE