Internal pressure testing of open-ended filament-wound cylinders using radial expansion of elastomeric inserts

A novel approach for generating internal pressure in filament-wound cylinders using the compressed elastomer method is investigated. Pressure is exerted on the inner surface of the cylinder by radially expanding elastomeric discs inside the composite cylindrical shell. This is accomplished by applying a uniaxial compressive load to the discs with the aid of rigs placed between compression platens in an ordinary universal testing machine. The digital image correlation (DIC) technique is employed to assist the tests in mapping both strain and displacement fields during the entire testing process. Cylinders with six different winding angles (±35°, ±45°, ±55°, ±65°, ±75°, and ±90°) are prepared and analysed. Their load-carrying capacity increases up to an angle of ±75°, accompanied by systematic changes in deformation and failure mechanisms. The suggested testing setup offers benefits in evaluating the impact of processing parameters on the internal pressure strength of filament-wound cylinders. It serves as a secure and cost-efficient laboratory-scale alternative to conventional hydrostatic pressure testing.