Investigating the impact of internal fatigue crack propagation in aluminum alloy plates repaired with a composite patch

The application of the Factor of Intensity of Constraint (FIC) criteria becomes instrumental in quantifying effectiveness by measuring the reduction in mechanical energy at the fracture tip, thereby extending the structural life. The robust mechanical properties offered by bonded composite patch repair technology, including enhanced fatigue resistance, mass gain, adaptability to complex sections, and corrosion resistance, play a pivotal role in fortifying damaged structures. Our findings highlight the interdependence of geometric and mechanical properties among the composite patch, adhesive, and damaged structure. Our investigation centers on M(T) aluminum alloy 6061 T6 centrally fissured samples from the 6000 series. We present a comprehensive examination of the effect of composite patch repairs on fatigue deterioration in aeronautical structures. Significantly, our study introduces novel insights by examining the effects of both constant and varying amplitude loads, emphasizing the contribution to comprehensive exploration that highlights the practical implications and benefits of composite patch repairs in enhancing fatigue resistance and longevity in aeronautical structures. Additionally, a detailed exploration is conducted to understand the effects of various parameter settings and service terms. This study contributes significant insights into the field, shedding light on the practical implications of composite patch repairs in enhancing the fatigue resistance and longevity of aeronautical structures.