Split-disk test with 3D Digital Image Correlation strain measurement for filament wound composites

The paper investigates the split-disk test methodology for measuring mechanical properties of a filament wound composite. Hoop strain is measured by three-dimensional (3D) Digital Image Correlation (DIC) on outer surface ring specimens. A finite element model (FEM) employed to investigate distribution along circumference and thickness effect friction between disk. FE simulation shows that disk significant, but precise quantification difficult because irregularities ring/disk contact. Both DIC map show low area at level split, caused local bending ring. In conclusion this work, authors recommend: (1) measure strain, which used in stiffness calculation with 10° offset from where influence becomes insignificant, (2) use 3D hoop measurement, concurrent FEM estimate errors related difference strains average over entire thickness.