Surface Effects on the Elastic Stress Field at Blunt Crack‐Tip in Mode I

ABSTRACT This study revisits the criteria of linear elastic fracture mechanics (LEFM), such as S‐criterion, within the framework of surface elasticity theory. The main objective is to establish the counterpart of stress intensity factor (SIF) of LEFM at micrometer or even nanometer scale, thereby extending fracture mechanics concepts within the framework of surface elasticity theory. To achieve this, a calibration methodology is proposed for determining a large set of real constants of Cauchy stress field that has been established in the literature. The stress field is transformed into a linear algebraic system. Next, the surface elasticity theory is implemented in COMSOL finite element code. The accuracy of the simulation results is validated against benchmark data from the literature. The calibrated Cauchy stress field should then be employed to revisit S‐criterion at the micrometer or nanometer scale. Finally, fracture toughness is analyzed within the framework of surface elasticity theory.