Abstract

Plane strain punch stretching test (PSST) was developed to evaluate stamping formability of sheet materials. In this test, the rectangular specimen of sheet material is uniformly stretched up to fracture by raising a specially designed punch to certainly assure plane strain stretching deformation along the longitudinal direction of the specimen. The stamping formability was evaluated by limit punch height(LPH) in plane strain punch stretching test compared to limit dome height(LDH) in hemispherical punch stretching test. LPH-value in PSST well ranks the stamping formability of various material and correlates with press performance. Moreover by using ultrasonic thickness gauge the plane strain intercept-limit plane strain(FLCo)-in forming limit curve can be accurately determined from thickness measurement around the fracture area. The FLCo derived from thickness measurement well correlates with the results from circle grid analysis for the deformed circle grid marked on the surface of the specimen.

Keywords

• plane strain punch strtching test;
• stamping formablility;
• limit punch height;
• plane strain intercept;
• ultrasonic thickness gauge

• 평면변형장출실험;
• 스탬핑성형성;
• 한계펀치높이;
• 한계평면변형률;
• 초음파두께측정기;