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 filamen t-wound ring specimens. Needle rollers are introduced between the dees and the ring to alleviate friction. Strain is approximately uniform t hrough the thickness of the ring except in the region of the split lin e 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 high lights some pitfalls.