Bulge-Test according to ISO 16808
Hydraulic Bulge Test
-according to ISO 16808-
A bulge test unit works according to the following method:
The sheet metal specimen is fixed between the drawing die and the sheet holder. Below the sheet specimen is a chamber filled with oil.
The sheet metal is clamped and can now be formed (without friction) with the help of the drawing piston, which presses upwards against the oil.
The thicker the sheet metal and the higher the strength of the material, the higher the drawing force required to form the sheet metal.
The required sheet holding force also increases because the sheet must be held securely in the circumferential bead.
The sheet specimen (2) is fixed between the drawing die (1) and the sheet holder (3). There is an oil chamber (4) under the specimen.
The sheet is clamped and can now be formed (without friction) with the help of the drawing piston (5), which presses upwards against the oil.
The thicker and stiffer the specimen, the greater the drawing force required to deform the sheet. The necessary sheet holding force also increases, as the sheet must be held securely in the circumferential bead. Only five selected reference points on the sheet are relevant for the determination of the parameters (see top view), which are used for the calculation of the dome radius and the dome height.
Test principle
Sheet metal sample
Testing machines
