Composite overwrapped pressure vessels (COPVs) have become a critical component in the storage of cryogenic fuels aboard rockets, satellites and spacecraft. Recent research has focused on reducing the cost of COPVs by replacing the inner metallic liner with a low cost alternative, or by removing the liner in its entirety. An integrally heated rotational moulding tool has been constructed and used to produce PEEK polymer liners which have been permeability tested using helium gas. PEEK samples have been overwrapped in a laser-assisted tape placement (LATP) process with a CF-PEEK tape. Cryogenic cycling of liner-overwrap samples has shown crack resistance over multiple cycles. A combined experimental and numerical approach to the design of linerless CF/PEEK LATP composite cryogenic tanks is also presented. Defect characterisation using 3D X-ray CT scanning, optical microscopy and cryogenic cycling has been undertaken. A novel XFEM cohesive zone methodology is used to predict damage in an internally pressurised cryogenic tank, to define an optimised tank lay-up which is resistant to microcrack formation.
|Title of host publication||3rd International Conference and Exhibition on Thermoplastic Composites - ITHEC 2016|
|Publication status||Published - 15 Oct 2016|
- COPVs, PEEK, Carbon Fibre, Tape Placement, Polymer Liners, Permeability, XFEM, Cryogenic Cycling, X-Ray CT