ART is interested in developing a double diaphragm for operation in a pressure chamber. The chamber is a pressure vessel made by assembling two hemispherical dome shaped vessels. The double diaphragm is sandwiched between the dome shaped vessels. The double diaphragm physically divides the whole pressure chamber into two cavities; upper cavity and lower cavity. The double diaphragm shall have a leak adaptor at its periphery. The leak adaptor shall be inserted and sandwiched between the diaphragms of the bladder at the periphery. The fatigue life of the diaphragm shall exceed the duration of maintenance, so that it can be replaced at each maintenance interval.
The physics involved in the simulation are complex and can be summarized as follows:
- Contact between the diaphragms and between the diaphragms and cavities had to be included.
- Pressure loading conditions on the diaphragms make it deform to 300 % strain and higher.
- Large expansion deformation along with multi-step analysis procedure had to be carried out.
- The diaphragm material is non-linear and needs to be fully defined for the design to be properly validated.