The Development of a Simple Method for Micro Strain Measurement Applied to Bulge Microhydroforming

摘要

Microscaie sheet metal forming represents a new and attractive solution to many manufacturing problems. Larger organizations are utilizing commercially available microscaie digital image correlation systems to measure the strains on the microscaie. The cost of these systems is preventing smaller research and development organizations from entering this challenging area, or they are sacrificing the ability to determine strains. The present paper describes the development of a simple method for determining strains on the microscaie. The method was able to measure true strains up to 0.618 for grids that are 97 microns. Microscaie strains from sheet bulge hydroforming experiments for 11 mm, 5 mm, and 1 mm diameter dies using the proposed method are presented and compared to results from finite element models and analytical solutions.