Our customer, who wishes to remain anonymous, is a manufacturer of articulated trailers. In 1999 a new trailer was designed for a particular region to negotiate unique, narrow and twisting roads while maximising the amount of cargo. Early prototype vehicles of the compact design proved to be successful and safe at all operational speeds, but it was noticed that on sharp turns one of the inside wheels would unexpectedly lift off the ground.
Although the wheel-lift did not impact safety, it was decided to request Randle to investigate the exact cause and to suggest a preventative measure.
Data was collated on the tractor, trailer, loading configurations, and on the rear-steer mechanism in order to develop an MBS computer simulation.
Within seven days the worst case driving situations had been identified and yet the results showed that the trailer was indeed statically stable until a second wheel lifted. Furthermore the event could be best suppressed through changes to the vertical suspension kinematics rather than to the rear-steer mechanism or the trailer geometry.
- Loading instructions provided for drivers
- Guidelines developed for future designs
- Rear steer system modelled and optimised
- Vehicle stability demonstrated to client and end users
Explicit vehicle modelling using PTC Pro/Mechanica