3. Coin Minting

This chapter addresses ongoing developments in the engineering design of coin minting processes by application of the finite element method. The presentation draws from a brief overview on the fundamentals of the quasi-static and dynamic finite element formulations based on implicit and explicit solution procedures to the application of the quasi-static finite element flow formulation to the numerical simulation of coin minting. Validation of the results from numerical simulations involved independent determination of the stress–strain curve of the disk material by means of stack compression tests, verification of the force values provided by the industrial coin minting press, confirmation of the estimates of the progressive filling of the relief coin features, and comparison of the numerical and experimental force versus die stroke evolutions for coins with different diameters and relief profiles produced by the Portuguese Mint. Results show that finite element analysis can be successfully applied to predict material flow and filling of the intricate relief coin features, to estimate the required coin minting forces, and to improve the design of the dies before fabrication.