A SIMPLE ALGORITHM FOR STAMPING CIRCULAR PLATES BY HEMISPHERICAL PUNCHES

This paper proposes a simple algorithm for solving the contact problem s in relation to sheet stamping. The efficiency and reliability of the algorithm are demonstrated by an investigation of the stamping of ela stic-plastic circular plates into a conical die with a hemispherical r igid 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 betwe en the punch and the plate surfaces does not disappear before coining. Using the proposed algorithm, the applicable range of the small defle ction theory of plate bending has been examined, revealing that the ap plicable range of this theory is much smaller than is usually thought. (C) 1997 Elsevier Science S.A.