Numerical and experimental analysis of dynamic oblique impact: Effect of impact angle

Surface failures under dynamic oblique impact occur in many mechanical systems. In automobile engine, valve seat insert works under complex vibrating conditions. This leads persistently to the evolution of contact pressure, stress and strain as a function of time. By simplifying the system to a ball-on-flat configuration, the contact dynamic behavior was investigated as a function of impact angle. In order to better understand experiments on the experimental bench test, a finite element model was developed. Experimental and numerical results show an evolution from permanent reciprocating sliding at low angles to an intermittent motion called multi-impacts at higher angles. Experimental electrical contact resistance measurements confirm the observed evolutions. As a consequence, shearing stress is reduced when plastic deformation is increased with multi-impacts.