On „VZN damper behaviour at crash

On landing operation, a brutal contact with the dech or ground, can damage the plane or chopper and hurt the pilot, the crew or the passengers. The paper presents the advantages confer by suspensions using VZN dampers, in this situation. The Romanian self adjustable damper (shock-absorber) concept- VZN-granted with European Patent EU 1190184 and Romanian Patent 118546 assures damping coefficients increasingly by stroke from lower value up to the very high values, giving thus possibility to dissipate a huge energy at all speed regimes high, medium or low. With a convenient damping valve placement and/or dimension, the VZN concept confers possibilities to assure constant decelerationforces, at the human body limit resistance, this solution dissipating the maximal energy ąuantity. The paper indicates solutions for VZN tuning in order to be used to realize constant deceleration at crash and developed one of them for a practical device realizes. The samples where developed so to be realized with components used in actual automotive shock absorber manufacturing, so prototypes being easy to realize. Despite the simulations was realized considering standard damper dissipating energy function piston speed, not sąuare piston speed, the standard damper dissipated 48.5% lower energy comparative to VZN one. This means in the same situation in which VZN damper reduces constant speed from 20 [km/h] to zero, the standard dampers reduces speed up to 11.5[km/h], then collapsing the aerial vehicle.