Experimental analysis of interfacial properties of sphere oblique impact with initial spin

Experiments of a sphere oblique impact with and without an initial spin have been carried out to obtain properties of the impact interface. The contact surface is recorded with a piece of thin carbon paper. The interfacial parameters measured are expressed as axis length, contact area and slip ratio. It is found that for the impact between steels the forward spin can make geometrical sizes of the contact surface increase compared with the case of no initial spin, however, just the reverse for the backward spin. The effect of the initial spin becomes more apparent for the impact with a rubber cushion. Whether the initial spin promotes or hinders the sphere sliding depends on the parameters of tangential velocity and force at the interface