The report presents results of a test program to validate applicability of six previously developed maneuvers in determining the influence of vehicle-in-use steering, suspension, and brake system degradations and tire factors on vehicle sub-limit handling. Six vehicles were tested which reflect subsystem design features and class size ranges representative of the majority of domestic and foreign vehicles-in-use in the United States. Test results show the maneuvers and procedures consistently produced measurable performance differences for the types and levels of subsystem degradations employed. The major handling detriment observed is nonlinear or discontinuous response for normal driver inputs (steer, brake, or throttle) which occurred for certain component degradations and vehicle acceleration levels. The tests also included an investigation into the influence of sagged coil springs and coil spring spacers on handling performance of two full-sized automobiles. The findings relate vehicle stability factor (a measure of the basic understeer intentionally designed into the vehicle steering and handling characteristics) and controllability with change in ride height, sprung mass roll axis, and suspension bump-stop bottoming. Results show consistent and measurable differences in handling parameters, depending upon location of sagged spring and use of spring spacers. The least desirable situation is asymmetric (i.e., one side only) sagged spring and spacer usage which produces different handling response in left versus right maneuvers and can lead to vehicle controllability problems.
Vehicles-in-Use Sub-Limit Maneuvers. Volume I: Executive Summary
1980
31 pages
Report
Keine Angabe
Englisch
Road Transportation , Transportation Safety , Automobiles , Structural members , Performance evaluation , Steering , Lateral stability , Braking , Helical springs , Dynamic response , Plymouth Horizon automobiles , Fiat X-1/9 automobiles , Chevrolet Vega automobiles , Chevrolet Citation automobiles , Volvo 240 automobiles , AMC Matador automobiles