The Role of Elastic Tangential Compliance in Oblique Impact

An extension of the Hertz theory of impact to the oblique impact of elastic bodies with circular contact is outlined. The tangential compliance of the contact surface under the action of Coulomb friction is shown to have a significant effect on the rebound angles, if the local angle of incidence does not greatly exceed the angle of friction. Experiments are described in which the trajectory of a moving body is measured before and after impact with a fixed block of similar material. Results obtained using both steel and rubber show good agreement with the theoretical values.