블록카운팅 기법을 적용한 항공기 구성품 수명 예측

Abstract

Although safety regulations for aircraft have strengthened over several decades, aviation accidents originating from fatigue fracture are still frequently reported. Thus, the importance of damage tolerance design increased to enhance the durability of aircraft components. In general, the lifetime of aircraft component is estimated by conducting simulation work, and the simulation results are compared with the fatigue crack growth rate. Since the comparison between theoretical and experimental fatigue growth rate is important for adjusting the theoretical analysis parameters, it is essential to accurately check the crack propagation behavior during component testing. Thus, in this work, fatigue crack growth in the aircraft component was measured by conducting a block counting method. The high tensile loading points in each block can be correlated with the strong striation marks, and the spacing between two blocks can be defined as a crack growth per each block. The present strategy revealed that crack initiation occurs before the 32nd block and propagates to 4.71 mm (for right side) / 5.91 mm (for left side) until the 36th block, which is the final testing block.