Surface profile topography of trimmed and drilled carbon/epoxy composite

The surface finish of Fiber Reinforced Plastic (FRP) laminate is challenging to characterize, due to the heterogeneous structure of the composite. Profile roughness parameters are highly impacted by the different layer properties, and their distributions are relatively spread out. In this paper, the surface topography of a 24-ply quasi-isotropic Carbon FRP (CFRP) is observed through primary profiles and the roughness parameter Ra in the transverse direction on trimmed and drilled CFRP surfaces. The surface characterization using the Ra parameter is found inadequate in providing useful information as to the machined surface quality.