基于实测数据的飞机结构疲劳强度评估研究

Study on fatigue strength evaluation of aircraft structure based on measured data

以提升飞机疲劳强度评估精度为目标,提出了基于实测数据的飞机结构疲劳强度评估方法。选取有限长单位冲激响应(FIR)数字滤波器预处理飞机疲劳强度实测数据,利用损伤容限额定值评定方法依据完成滤波的实测数据评价机队中含孔结构裂纹以及各种检查方法的裂纹扩展曲线,依据裂纹扩展曲线生成检查周期-损伤容限额定值(DTR)曲线,所生成曲线可直观展示不同检查周期的DTR,实现飞机结构疲劳强度评估。实验结果表明,所提方法可实现飞机结构疲劳强度精准评估,且白噪声干扰下评估精度很高。

In order to improve the accuracy of aircraft fatigue strength assessment,an aircraft structural fatigue strength assessment method based on measured data is proposed.The finite impulse response(FIR)digital filter is selected to preprocess the measured data of aircraft fatigue strength.The crack propagation curves of the structure with holes in the aircraft fleet and various inspection methods are evaluated according to the filtered measured data by using the damage tolerance rating method.The inspection cycle-damage tolerance rating(DTR)curve is generated according to the crack propagation curve.The generated curve can visually display DTR values of different inspection cycles,thus realize the fatigue strength evaluation of aircraft structures.The experimental results show that this method can accurately evaluate the fatigue strength of aircraft structure,and the evaluation accuracy is very high under the interference of white noise.