Effect of Stress Interactions on the Closure of Elliptical and Nonelliptical Cracks

Previous studies have shown that stress interactions affect crack closure, yet no work has so far quantified such effects for different crack types. This study introduces an analytical solution for the deformation of elliptical and nonelliptical cracks, excluding stress interactions. A comparison with numerical simulations incorporating stress interactions enables the quantification of deviations attributable to them. Results indicate that stress amplification accelerates crack closure, whereas shielding slows it. The elliptical model is more sensitive to stress interactions than the nonelliptical one, with its closure behavior more strongly affected by crack interactions. In randomly distributed cracked models, nonelliptical cracks exhibit progressive closure due to cooperative major- and minor-axis deformation, leading to greater distance between the cracks and thus effectively attenuating local stress interactions. Therefore, their numerical results agree markedly better with the single-crack analytical solution. For cracks with small aspect ratios (<0.001), both elliptical and nonelliptical cracked models undergo rapid closure, yielding a narrow window for stress interactions and thus a close convergence between actual results and the single-crack reference model.