Isabella quarter is without distinction". The "American Journal of Numismatics" had other criticisms of the quarter: Minting of what Barber dubbed "showy quarters" began at the Philadelphia Mint on June 13, 1893, six weeks after the exposition opened. Leech had planned to strike the pieces using polished blanks, or planchets, and workers at that mint handled the coins carefully; unlike the half dollar, surviving specimens display relatively few contact marks from other coins. The first piece struck, along with numbers 400, 1,492, and 1,892, were struck in proof condition and sent to the Lady Managers along with certificates attesting to their status.
Sheet metal forming simulation address a tearing problem in a metal stamping operation. A simple simulation model was created to determine the effect of blank edge radius on the height to which the material could be formed without tearing. Based on this information a new die was designed that solved the problem. There are lots of sheet metal programs available in the industry as SolidWorks and LITIO. Sheet metal forming simulation Today the metal forming industry is making increasing use of simulation to evaluate the performing of dies, processes and blanks prior to building try-out tooling. Finite element analysis (FEA) is the most common