A new design of end-tab for the tensile testing of unidirectional thermoplastic composites CF/PA6

This study proposes a new design of end-tab for the tensile testing of unidirectional (UD) carbon fiber reinforced thermoplastic polyamide-6 (CF/PA6) to reduce stress concentration at the tab end. The new tab has the same length as the UD CF/PA6 specimen to avoid the sudden change of geometry as seen in conventional tabbed specimens. Three kinds of UD CF/PA6 materials made from different manufacturers are used for the fabrication of tensile specimens. Specimens with new tab and conventional non-tapered tab are tested, respectively. Finite element simulations of tensile testing for UD specimens with new and conventional tabs are carried out. Experimental and simulation results demonstrate that the new tab design can reduce the stress concentration near the tab end by about 10% and improve the estimation of tensile strength of UD thermoplastic composite laminates.