Life Analysis of 2A12-T4 Aeronautical Aluminum Alloy Under Alternating Mode of Corrosion Fatigue with Load Interaction
Based on the alternate mode of"ground corrosion and air fatigue"damage during aircraft service,this paper consid-ers the interaction between loads to study the fatigue life degradation and damage accumulation of aviation aluminum alloy 2A12-T4 under alternate modes of pre-corrosion and"corrosion + fatigue"law.Under the same level of loading conditions,it is proposed to use the corrosion fatigue coupling damage index and the hysteresis load to describe the alternate corrosion fatigue damage mode.The interaction between the fatigue damage at various levels and the coupling effect of corrosion damage and fa-tigue damage during service work are used to describe the mutual promotion and accelerated deterioration of corrosion and fa-tigue.Based on damage mechanics and non-linear accumulation theory,the traditional Miner linear accumulation damage theory is modified by considering the corrosion fatigue coupling index and hysteresis load.The life calculation model of aircraft structural materials is established,and the calculation results of the model are compared with the test results.The corrosion cou-pling damage is determined in the corrosion experiment,and a uniformly distributed hysteretic load is obtained by using the theory of low-load exercise effect.The calculation results show that the results of the life calculation model proposed in this paper are more consistent with the test results.