Size dependence of the fracture toughness of copper nanostrips under tension

This paper investigates the size dependence of the fracture toughness of single-crystal copper nanostrips. Atomistic simulations are conducted on center-cracked nanostrips under tension, and atomic interactions are described by the embedded atom method potential. Fracture toughness is measured as the critical value of the strain energy release rate, and fracture toughness based on the Griffith fracture criterion is obtained by calculating crack-surface formation energy. To verify linear elastic fracture mechanics at the nanoscale, the J integral is evaluated using the finite-element method. The results show the value of fracture toughness obtained from atomistic simulations and the finite-element method to be influenced by the width.