Kerf taper and delamination damage minimization of FRP hybrid composites under abrasive water-jet machining

Kerf taper and delamination are undesirable geometrical defects inherent to abrasive water-jet machining (AWJM) of layered fibre reinforced polymer composites. This is mainly attributed to the characteristics of water-jet energy as well as the anisotropic nature of the material. The present research describes an experimental investigation into minimizing the aforementioned defects for hybrid fibre reinforced polymer composites. Experimental results reveal that the kerf ratio was mainly influenced by the stand-off distance and traverse rate. Both sides of delamination were influenced by abrasive flow rate, traverse rate, and hydraulic pressure. Minimum kerf ratio and delamination damage can be achieved by increasing the kinetic energy of abrasive waterjet stream when impinging under a lower cutting speed. Response surface methodology (RSM) was employed for establishing empirical relationships between experimental outputs and controlled parameters. Confirmation tests have a variance of within 5% for both outputs via comparison between experimental values and the regression models.