Load interaction effects on fatigue crack propagation in 2024-T3 aluminum alloy

摘要: Abstract Variable amplitude fatigue studies have been conducted within a linear-elastic fracture mechanics framework in order to systematically examine the effect of complex loading on crack retardation 2024-T3 aluminum alloy. Complex conditions were simulated by introducing second tensile or compressive peak load after had extended various distances, a' , into region affected previously applied high excursion. Maximum interaction between single overloads resulted when two cycles separated small distance, min where propagation rate resulting from overload reached minimum. This behavior was attributed part interference displacements produced during first cycle which verified fractographic observations. Crack growth related also development favorable residual stress at tip. Peak loads found act as completely isolated events only they distance approximately three times plastic zone size overload. Comparable findings 10 block employed place excursions. When followed cycle, decrease minimum; however, sequence reversed, less damaging. In addition, positive and negative increased, number delay quickly approached that associated with