Fatigue life prediction and influencing factors analysis on taxiway bridge

ObjectiveTo predict the fatigue life of taxiway bridge and analyze its influencing factors, a new fatigue life prediction method for taxiway bridges was proposed based on the fatigue cumulative damage theory and finite element software Abaqus.MethodFirst, a solid model of taxiway bridge was established, combined with engineering cases. Errors between simulation result and measured data were within a reasonable range. It verified the validity of model. Second, the fatigue stress was calculated by using rain-flow counting method. Finally, the damage degree was calculated based on S-N curve. The fatigue life was predicted using the Miner theory. The influences of aircraft sorties growth, steel bar corrosion, stiffness degeneration and bridge panel cracking on the fatigue life of taxiway bridge were analyzed.ResultThe simulated dynamic response of taxiway bridge under aircraft loads is consistent with the measured result. An increase in aircraft sorties significantly affects the damage degree of taxiway bridge panels. Specifically, when overall aircraft sorties increase by 50%, the fatigue life of bridge panel will decrease by about one-third. The steel bar corrosion rate has a substantial influence on the fatigue life of taxiway bridge. When the steel bar corrosion rate is no more than 3%, the fatigue life shows a linear downward trend. When the corrosion rate reaches 20%, the fatigue life of bridge panel decreases by approximately 97%. Distresses, e.g., cracks occurring during the operation of taxiway bridges, will lead to a reduction in the overall structural stiffness. The stiffness degeneration of bridge panel is characterized by the crack density of taxiway. As cracking severity deepens, the fatigue life of taxiway bridge declines rapidly. When the bridge panel is severely cracked, the fatigue life of taxiway bridge decreases by 63.57%.ConclusionThis study clarifies the influence of multiple factors on the fatigue life of taxiway bridges. The findings have significance for the performance evaluation and safe operation of airport taxiway bridges.