A study of the Suspension System for the Diagnosis of Dynamic Characteristics

Some of the common faults associated with
suspension components are damaged or leaking shock
absorbers, spring weakness, wearing down of the pivot and
bushing and damage to the main support member assembly.
To investigate these problems, a seven degree-of-freedom (7-
DOF) model has been developed, for a full vehicle, using
MATLAB. In the simulation, the suspension faults have
been considered via the damage caused to the shock
absorbers (dampers) and the faults were seeded by reducing
the damper coefficient by 25%, 50% and 80%. This has
formed the basis for the characterisation of the ride
comfort, road handling and stability of the car.
The parameters able to offer a comfortable ride for the
passengers were found to be in conflict with the parameters
ensuring the stability of the vehicle and the corresponding
wheel travel. For a high level of ride comfort, the suspension
requires a shock absorber with a low damping coefficient.
However, for optimum stability and a minimum level of
wheel motion, the suspension requires a shock absorber
with a high damping coefficient.