Yutaka Iwahori

Thermomechanical Properties and Microcracking Behaviors of CFRP Laminates Using CSCNT-Dispersed Epoxy

Ply-level microscopic damage behaviors (i.e. microcracking) were investigated using cross-ply laminates of the CFRP using cup-stacked carbon nanotubes (CSCNTs) dispersed epoxy in tension tests. The dispersion ratios of CSCNTs to epoxy resin were 0, 5, and 12 % in weight. The basic thermomechanical properties of CSCNT-dispersed unidirectional CFRP were measured, and the accumulation behaviors of matrix cracks in 90 o plies of CSCNTdispersed CFRP laminates were observed as a function of the applied strain using soft X-ray radiography. It was demonstrated that the dispersion of CSCNT resulted in an increase in interlaminar fracture toughness and retardation of microcracking onset and accumulation. The effects of CSCNT dispersion on the fracture resistance characteristics are examined by observation of fracture surfaces. An increase in fracture surface due to crack deflection in CSCNT-dispersed CFRP is considered to be the main contribution to the improvement of fracture resistance.