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Tool & Die Authority - November 2008
The Tool and Die Authority November 2008 Newsletter contained these articles:
Time for Tooling Industry to Step Up and Train: Joe Brown
Failure Analysis for Stamping Dies—General Procedures: Peter Ulintz
Time-Saving Alternative to Six-Sided Grinding—Part 1: Bob Quinn
and from Danny Schaeffler of Engineering Quality Solutions (EQS)
Circle Grid Strain Analysis—Confirm that Ellipse Measurements Make Sense
Visit the Precision Metalforming Association website to learn how to subscribe!
Time for Tooling Industry to Step Up and Train: Joe Brown
Failure Analysis for Stamping Dies—General Procedures: Peter Ulintz
Time-Saving Alternative to Six-Sided Grinding—Part 1: Bob Quinn
and from Danny Schaeffler of Engineering Quality Solutions (EQS)
Circle Grid Strain Analysis—Confirm that Ellipse Measurements Make Sense
Last month, we learned that the measurement technique used to determine the dimensions of a deformed ellipse is critical, and that the proper method is to measure from the center-width position of the line that makes up the circumference around the circle.
In this month’s column, I’ll discuss a simple method to confirm that your ellipse measurements make sense. A flat sheetmetal blank has known length, width and thickness dimensions. Since material formability is not exempt from the laws of physics, the total amount of material must maintain a constant volume before, during and after forming, even though the specific values of length, width and thickness will change as a result of forming. This allows for calculation of a thickness strain (et), since the major (eMA), minor (emi), and thickness strains in that volume of material multiplied together must equal 1 ...
Visit the Precision Metalforming Association website to learn how to subscribe!