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Introduction to Circle Grid Strain Analysis and Thickness Strain Analysis

What is circle grid analysis and what is it used for?

Circle grid strain analysis and thickness strain analysis are tools for evaluating stamping process robustness and to see if the chosen sheet metal is appropriate for the current state of tool development and stamping process. It's called circle grid because in the traditional application process, circles are electrochemically etched on the sheet steel surface. Thickness strain analysis is conducted with the aid of either an ultrasonic thickness gauge or a pair of micrometer/calipers.

Read our ASM Handbook Article "Troubleshooting Forming Problems Using Strain Analysis"

In this article you'll learn:Circle Grid

  • Strain Calculations
  • Deformation Modes
  • Limit Curves (FLC)
  • Forming Limit Diagrams (FLD)
  • Safety Margin (Also Known As Safety Factor)
  • Tools & Techniques for Thinning Strain Analysis (TSA)
  • Tools & Techniques for Circle Grid Strain Analysis (CGSA / CGA)
  • Strain Calculation Example
  • Measuring Strains Using a Calibrated Mylar Strip Ruler
  • Measuring Strains Using Automated Grid Reading Techniques
  • Plotting Strains on A Forming Limit Diagram
  • Thinning Limit Curve and Marginal Thickness Determination
  • Bead Correction Factor
  • Measuring Small Strains Distributed Over Large Areas
  • A Reference Panel to Check Production Process Robustness
  • Strain Analysis for Statistical Process Control
  • How Strain Analysis Techniques Affect Part Safety Assessment

For detailed information on circle grid analysis and thickness strain analysis, please enter your email address and password to download our article published in the ASM Handbook. 

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