Quantitative study on the damage of pores to pure aluminum during fatigue process at nanometer scale

Aluminum alloys are widely used in critical structures but suffer from fatigue life reduction due to manufacturing-induced pores. Molecular dynamics simulations reveal pores induce stress concentration and cyclic softening, with sharp crack initiation sites forming during deformation. Shear bands between multiple pores accelerate crack coalescence. Tensile tests show strength decreases from 7.5GPa (perfect) to 2.3GPa (multi-pore). A static toughness-based damage model quantifies 5.7× and 7.6× faster damage accumulation in single- and multi-pore models versus perfect. This study provides theoretical guidance for aluminum alloy anti-fatigue design.