Hydraulic bulge test in hydroforming. As with all operations creating shapes and parts out of metal, the stress and strain must be tested to ensure safety. If a company is creating car roofs using hydroforming out of sheets of metal, hydraulic bulge testing can help determine if the car roof can take the required stress and strain of driving and even accidents.
The hydraulic bulge test is most appropriate when creating a new product to determine if the original pressure settings are appropriate. Once the bulge test indicates the product retains shape after testing, then production can produce multiple versions of the product. In the case of the car roof, once it is determined the optimum shape and thinness of the shape, then that design can be mass produced.
Hydraulic Bulge Test
First, sheet hydroforming is used to create that car roof out of a sheet of metal. The sheet of metal is put into a die and high pressured liquid is used to bend it into the desire shape and even into a desired thickness. With this process, many car roofs can be created that all conform to the same standards.
Second, some of the car roofs are tested. The bulge test is when the metal sheet is placed in a die that has a circular opening. That sheet is then clamped into place and more high pressure is used to test if it can withstand the strain of additional high pressure. If the pressure causes the formed car roof to bulge, then we know the car roof cannot take the strain and safety is compromised. If the car roof cannot take the pressure, then the process must be evaluated before more car roofs are manufactured.