Embedded optical fibres for monitoring pressurization and impact of filament wound cylinders

Abstract

Filament wound composite pressure vessels have found use throughout many industries for storing high-pressure gases. The ability to investigate the vessels for possible damage from accidental impact loads is important for applications in the transport sector. Standard non-destructive methods are complicated. This paper describes a method to permanently monitor pressure vessels for their structural integrity.

The method is based on standard telecommunications grade optical fibres embedded in the composite overwrap as a network of distributed strain sensors. Challenges regarding the practical implementation of optical fibres, and post-processing of signals, are discussed. During pressurization, the optical fibres were used to measure strains in several thicknesses of the composite layup. The cylinders were impacted and the backscattered light from optical fibres was then analysed to visualize the position and the severity of damage. The interrogation of embedded optical fibre networks is successfully demonstrated as a promising method for structural health monitoring of composite pressure vessels.