Abstract: Dynamic loads acting on a twin-tube hydraulic shock absorber are derived out both in the wheel and the axle planes by modeling mechanically car rear suspensions, and internal and external forces of the piston rods are analyzed according to the testing data and the practical parameters. From viewpoint of the whole car assembly, due to the piston rods hardly perfectly placed in their positions between suspension and body causes an additional dynamic loading. Key factors such as road unevenness, very high car speed and severe shock induced vibrations are studied, which lead to sudden bending moments and dramatically increasing shock loading. All these possibilities may easily produce one-side wear-out and tribocorrosion of the piston rods of the rear suspensions. Valueable results presented from theoretical and experimental analysis are systematically significant and improvement of the shock absorbers.

Key words: Suspension system, One-side wear-out, System dynamics