R Bakhtiari - Department of Mechanical Engineering, Sahand University of Technology
N Choupani - Department of Mechanical Engineering, Sahand University of Technology
A Sharifi - Department of Mechanical Engineering, Islamic Azad University, Karaj branch, Iran
M Heidari, - Department of Mechanical Engineering, Islamic Azad University, Karaj branch, Iran.

This paper investigates mixed-mode interlaminar fracture behavior in UD carbon/epoxy composite material based on numerical and experimental analyses. A modified version of Arcan specimen was employed to conduct a mixed-mode fracture test using a special loading device. A full range of mixedmode loading conditions including pure mode-I and pure mode-II loading were created and tested. Using the two-dimensional finite-element results, correction factors were applied to the UD carbon/epoxy fracture specimens. Moreover, the correction factors were determined via two- and threedimensional analysis and the results were compared. By employing experimentally measured critical loads and the aid of the finite-element method, mixed-mode interlaminar fracture toughness for the composite under consideration determined. Results indicated that the interlaminar cracked specimen is tougher in shear loading condition and weaker in tensile loading condition.

Delamination; Finite Element Analysis; Fracture toughness