A simple algorithm for stamping circular plates by hemispherical punches

This paper proposes a simple algorithm for solving the contact problems in relation to sheet stamping. The efficiency and reliability of the algorithm are demonstrated by an investigation of the stamping of elastic-plastic circular plates into a conical die with a hemispherical rigid punch. The analysis shows that the contact stress varies greatly with the punch displacement and deviates from the uniform distribution used for approximate analyses. It is found that the central gap between the punch and the plate surfaces does not disappear before coining. Using the proposed algorithm, tile applicable range of the small deflection theory of plate bending has been examined, revealing that the applicable range of this theoD' is much smaller than is usually thought. © 1997 Elsevier Science S.A.