In studying the dynamic behavior of a body under impulsive loading, it may be fundamentally important to analyze elastic/plastic deformation at a contact part and to analyze the impulsive force generated at that part. So, in this study, the deformation at the contact part and the generated impulsive force were measured through the experiments in which aluminum bars collided axially, perpendicularly against the impact surface of a sensing plate which had been devised by one of the authors. The aluminum bars used had contact ends in the shape of the circular cone or truncated cone (frustum). The impact velocity of the bars was varied from 0 to about 11m/s. It was found through the experiments that a new truncated cone was formed at the contact end, and that the conical angle of the cone depended only on the conical angle of the former cone before the collision. It was also confirmed that the generated mean stress of the boundary plane between the deformed part and the undeformed part at the impact end was constant independently of the shape of the cone and of the impact velocity.
A simple and practical formula was derived with which the impact force generated at the contact part can be estimated for the collision of a body having a convex surface against a rigid wall, and a good agreement with the experimetnal results was obtained.
