Study on fatigue life dispersion of aluminum alloy structures with different damage sizes

Abstract

Fatigue life scatter factor of damaged aircraft structures is an important parameter to analyze their fatigue life dispersion degree. The fatigue test of prefabricated damage test pieces is carried out for aluminum alloy materials commonly used in aircraft manufacturing. The distribution type of residual fatigue life of damaged structures is determined by correlation coefficient comparison method. The relationship between damage and fatigue life and the dispersion of residual fatigue life of damaged structures are analyzed through fracture observation and statistical data processing. The results show that the residual fatigue life of damaged structures is more subject to Weibull distribution. The fatigue life of structures with preset damage decreases significantly than that of structures without preset damage. With the increase of preset damage size, the residual fatigue life of structures gradually decreases, and the residual fatigue life dispersion increases. The fatigue life dispersion difference of structures with different initial damage is great. The present work provides a reference for establishing fatigue life scatter factor models of aluminum alloy structures with different damage sizes.

Keywords

• damage
• fatigue test
• residual fatigue life
• weibull distribution
• dispersion