Sustainable Investigation on Metal Coin Clipped Blank, Using 3D Modeling and FEM Analysis

The modern coinage industry ensures for its products dimensional and weight precision and also an improved surface quality. The speed of coin mass production requires increased performance for the used machines and tools. Despite of these, the errors incidence cannot be excluded. Some of these errors are recorded inside the punching machine, and generates the clipped blank disks; on their turn those malformed discs led to the clipped coins. In the first part, the paper presents the premises insight the clipped blanks apparition. There are exemplified some coins having different types of clips: curved, straight and ragged. The literature review in the coinage field covers the subjects as coin and dies behavior under the striking load, viewpoints on 3D modeling and FEM analysis, respectively insights on various striking errors, most of them more or less valuable as collection metal pieces. The paper main purpose is outlined: to study, using the available modern techniques, the particularities of different clipped coin types. In the paper second part, is introduced the adequate 3D model, for such parts as the dies, collar, respectively the coin. It follows the assembled model corresponding to each studied case, which consist by the obverse and reverse striking dies and the collar, having inside them the coin. For each of the models, based on initial conditions, the finite element analysis is realized. The paper last part presents the analysis results, the discussions and conclusions.