Mechanical Design and Analysis of CNT Modified Carbon Fibre Composite Pressure Vessel

Performance to weight ratio is one of the critical parameters to consider while designing components for aerospace applications. Furthermore, even the most minor reductions in weight can significantly improve the efficiency of the vehicle. Conventionally, pressure vessels are manufactured in parts using metals like steel or aluminium alloys, joined together by welding or bolts. This makes the vessel body weak at the joints resulting in potential sites for critical failure. The use of composite alternatives can minimise the weight and risk of failure. Carbon fibre reinforced polymer composites with multi-walled carbon nanotube modified epoxy have exhibited remarkable mechanical properties, which can be utilised to design a pressure vessel of improved strength over conventional metals while being significantly lighter. Carbon nanotubes are nanoscopic hexagonal tubular structures consisting of hybridised carbon atoms, with multi-walled carbon nanotubes having multiple nested single-walled nanotubes. This paper aims to design a composite pressure vessel for working fluid storage for a reaction control system intended to stabilise and reorient a sounding rocket after the end of its powered flight. The vessel was modelled specifically to a sounding rocket airframe. Material testing was done using ASTM Standards for composite testing, following which values for material properties were obtained. Static structural analysis was performed using a direct solver on the vessel under-mounted conditions in ANSYS. Contours for maximum principal stress, maximum shear stress, total deformation and radial deformation were extracted and examined. This paper aims to further the research on Reinforced Fibre Composites (RFP) and nano-reinforcements in the aerospace industry by exploring its possibilities in terms of improvements to mechanical design and providing a basis for future applications.