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Bulge Test to ISO 16808

The hydraulic bulge test to ISO 16808 is a test method used in materials testing for the determination of sheet metal forming properties.

In a bulge test biaxial stress-strain curves are determined on sheet metals using a hydraulic cupping test. A metal blank (specimen) is fully clamped between the matrix and the blank holder. Under the specimen there is a chamber with oil. The drawing die pushes the oil up. The continuously increasing oil pressure leads to a curvature in the specimen. The test is run until a crack occurs.

Following the bulge test, the flow curve can be determined. For this the oil pressure, the evolution of the sheet metal thickness during the test and the optical measurement and assessment of the curvature in the sheet metal are evaluated.

The test is similar to the FLC test with Nakajima die. The cupping procedure however, takes place without friction.

Additional Cupping Tests

Cupping test to Erichsen/Olsen

Cupping tests to Erichsen (ISO 20482) and Olsen (ASTM E 643-84) are used to determine the stretching capacity a of sheet metal.
to Cupping test to Erichsen/Olsen

Forming limit curve (FLC)

With a forming limit curve to ISO 12004, the failure limit of a sheet metal can be determined.
to Forming limit curve (FLC)

VW test

In the VW test, the waviness of sheet metal for the body exterior is tested.
to VW test

Related Products for Performance of the Bulge Test to ISO 16808