Validation Of The Mvma Hsri Phase Ii Straight Truck Directional Response Simulation

Validation tests of the MVMA/HSRI straight truck directional response computer simulation program were conducted. A three-axle straight truck was instrumented and operated through test maneuvers both empty and loaded to 44,500 lb gross vehicle weight. Constant radius, steady-state cornering tests were run over a range of speeds up to limit cornering levels. Stepsteer transient tests to beyond the vehicle stability limit were also performed. Computer simulations of the test maneuvers were compared against the measured response of the test vehicle. The simulation exhibited good agreement with the experimental results in prediction of low-speed cornering, understeer characteristics and transient response. Disparities in the validation due to lack of tire relaxation length and steering system compliance models in the computer simulation were noted.