Combined Loading Simulation Test

This test is a combination of a cornering simulation and a braking or traction simulation. Simultaneously, a lateral and longitudinal g loading is specified, corresponding roll and pitch moments are applied to the chassis, and corresponding ground plane forces (lateral and longitudinal) are applied at the four tire contacts.

The vehicle chassis is exercised to match known on-road/track conditions of interest. Typically this is done for several conditions through a known corner (for example, corner entry, mid, and exit). Using acquired vehicle data (such as damper pots, steering sensors, etc.) it is possible to load a vehicle with roll and pitch moments and corresponding lateral and longitudinal tire loads. Some vehicle information is required in order to properly set up this test, namely: Overall CG height, desired braking and cornering acceleration levels, steering position (handwheel, rack travel, etc.), aerodynamic downforce loads, front/rear brake %, and banking angle (if applicable).

After running the combined loading simulation, the chassis motion is replayed through the rig without the ground plane forces present. This allows you to separate kinematics effects from compliance effects.

Here are some characteristics that are measured in a Combined Loading Simulation Test:

  • Axle Steer
  • Steer Rate
  • Camber Rate
  • Jacking Forces
  • Roll Rate (per G)
  • Pitch Rate (per G)
  • Roll Stiffness Total
  • Tire COP Migration
  • Tire Deflection Lateral
  • Roll Rate (per Torque)
  • Pitch Rate (per Torque)
  • Tire Lateral, Longitudinal, & Vertical Forces
  • Dynamic Cross Weight
  • Friction / Hysteresis