Too many passengers die or injure every
year because of highway accidents. Most of the vehicle manufacturing companies
are unable successfully to control this matter.
This paper handles the optimal design
of a passive spring-damper buffer that can be attached to the vehicle from its
front, rear or both sides to avoid catastrophic effects due to collision. The
optimization toolbox of MATLAB is used to minimize an absolute error objective
function to keep the dynamic motion of the crashing vehicle to below certain
level without destroying the standing hit vehicle. A 100 mm level is set for
this dynamic motion. The crashing speed is varied between 20 and 140 km/h and a
vehicle mass in the range of 1000 to 6000 kg is considered. The required
optimal values of the spring stiffness and damper damping ratio are defined
against the crashing speed.
The whole process is reduced to the
selection of a unit set of buffer parameters to protect crashing small and
medium vehicles at speeds ≤ 140 km/h with maximum dynamic motions less that the
100 mm level. This reduces the whole design process to a passive buffer with
88.776 kN/m stiffness and a 2250 kNs/m damping coefficient. This avoids the need to active and semi-active
expensive techniques.
