Experimental and numerical investigation on the mode I and mode II interlaminar fracture toughness of nitrogen-doped reduced graphene oxide reinforced composites

Soyugüzel T., Mecitoğlu Z., Kaftelen-Odabaşı H.

Theoretical and Applied Fracture Mechanics, vol.128, 2023 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 128
  • Publication Date: 2023
  • Doi Number: 10.1016/j.tafmec.2023.104103
  • Journal Name: Theoretical and Applied Fracture Mechanics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Aquatic Science & Fisheries Abstracts (ASFA), Communication Abstracts, Compendex, INSPEC, Metadex, DIALNET, Civil Engineering Abstracts
  • Keywords: Carbon fiber reinforced polymers, Cohesive zone model, Delamination, Fracture toughness, Reduced graphene-oxide
  • Istanbul Technical University Affiliated: Yes


An experimental and computational study is carried out to investigate the toughening effect of nitrogen-doped reduced graphene-oxide particles (ND-RGOP) in mode I and mode II delamination of carbon fiber/epoxy laminates. For mode I, both delamination initiation and propagation toughness are enhanced by 126.3% and 119.3% with 0.8 ND-RGOP addition. In addition to mode I toughness enhancement, ND-RGOP reinforcement also increases mode II toughness. The highest mode II delamination toughness value was obtained in 0.4ND-RGOP laminates with an increase of 45.6% compared to neat laminates. However, as seen in the bending tests, the maximum force of the end notch bending (ENF) specimens with 0.8 ND-RGOP added is not lower than that of neat laminates. The interlaminar fracture toughness is high due to the rough path of delamination with ND-RGOP addition, which is also observed by FESEM images of the delamination surfaces. In addition to the experiments, a cohesive zone model with parametric traction stress value was prepared in ABAQUS/CAE to obtain the critical traction stresses in the delamination of laminates. The critical normal traction stress of double cantilever beam (DCB) specimens is increased by over 20% with the addition of ND-RGOP. Besides, the critical interlaminar shear stress in mode II delamination for ENF samples is significantly improved.