Effect of ZnO-decorated electrospun veils on the damage tolerance of CFRP laminates

In this work, multifunctional carbon fiber reinforced polymer (CFRP) laminates were manufactured by inter-leaving electrospun veils decorated with ZnO nanorods (NRs) (CFRP_NY_ZnO). The laminates were tested under dynamic (low velocity impact at 5.0 J and 7.5 J) and quasi-static (pre-and post-impact four-point bending tests) loading conditions. The delamination resistance of CFRP_NY_ZnO was compared with those of CFRP (without veils) and CFRP_NY (with four non-decorated veils) laminates. At 5.0 J, ZnO NRs enhanced the delamination resistance (the lowest delaminated area was around 232.3 & PLUSMN; 38.7 mm2) due to additional energy consuming mechanisms. When the impact energy was increased (7.5 J), the debonding of ZnO NRs from the nanofibers was promoted and a rapid failure propagation was observed (increase in delaminated area of about 27% with respect to CFRP_NY). In quasi-static condition, ZnO NRs proved to be effective in increasing flexural strength (914.4 MPa (& PLUSMN;18.8 MPa)) and modulus (83.6 GPa (& PLUSMN;0.3 GPa)) of the laminate with respect to CFRP and CFRP_NY and in preventing laminate stiffness losses even after impacts at 5.0 J and 7.5 J.