Three different novel sandwich coupon designs comprising continuous unidirectional
protective layers were directly compared with standard coupons to assess their potential
to fully eliminate stress concentrations near the gripped regions. The gripping conditions
were optimised using different grade sandpaper tabs at the end of the sandwich coupons.
The sandwich type coupons yielded statistically significant increase in their average
failure strain compared to that of the baseline tabbed coupons. However, the three
sandwich coupon types did not show significant differences.
