Damping graphs has nothing to do with resonance. Resonance is affected by damping for sure. Draw light damping , heavy damping and critical damping in the same axes so that you know effect of damping on the same system. The graph above shows the desirable effect of shock absorbers to achieve critical damping . If it oscillate you can say it's underdamped.If the spring is too stiff (k value too large) than it's overdamped. Just enough damping, returning to equilibrium in the shortest time possible T/4, it's critical damping. Shock absorbers is an important component in cars , bicycles and in fact all vehicles including the aeroplane. Shock absorbers are found in washing machine, blender , etc. Watch this video showing critical damping , as the barrel returns to its original position in the quickest possible time after firing.Video below is taken from this link : reliability.equipment.com
