A Tool for Rapid Vehicle Suspension Design 2004-01-3543

This paper describes the development of a vehicle suspension analysis tool that is fast enough to be used at the suspension concept design stage. Standard suspension types can be analysed using pre-filled templates that provide easy creation of a kinematic model, in either 2D or 3D modes. The effects of bushes are included and the user can easily modify the rate, position and orientation of any bush. The available pre-built template types include double wishbones, Macpherson struts, trailing arm, semi-trailing arm, pull-rod and push-rod damper actuation, ‘A’ frames and ‘H’ frames. Unique suspension configurations can be constructed for analysis using the user definable template feature. The elasto-kinematic analysis calculates camber angle, castor angle, toe, kingpin angle, roll centre position, damper ratio, spring ratio, track change, wheel-base change, brake steer, lateral force compliance/steer and other quantities used by the designer in optimising a suspension layout.

Results can be displayed either graphically or numerically over specified bump, rebound, roll and steer articulations. The suspension hard points can be picked on screen and simply edited, or dragged on the screen, to review changes to the suspension characteristics - the calculation is virtually instantaneous. The effect of point tolerance on the calculated suspension derivatives can be calculated and displayed through the same interactive environment, by simply selecting the point and setting the tolerance.