Roller-assisted variant of the split disc test for filament-wound composites

The split disc method for materials testing is modified to facilitate the determination of stress-strain characteristics of suitable filament-wound ring specimens. Needle rollers are introduced between the dees and the ring to alleviate friction. Strain is approximately uniform through the thickness of the ring except in the region of the split line where bending is present. Both an analytical approach (based on beam-on-elastic-foundation theory and contact mechanics) and a non-linear finite element analysis show that this effect is localized. Experience of using this test demonstrates the usefulness of the method and highlights some pitfalls.