民机疲劳试验载荷谱简化研究与验证

在常规试验技术下,民用飞机全机疲劳试验周期过长,不仅费用高,更影响到适航取证和服役使用,开展载荷谱简化研究可有效加速疲劳试验。结合细节疲劳额定值(DFR)法和线性损伤累积理论,建立以损伤比门限值为折算依据的载荷谱等损伤折算方法。选用螺接和铆接的两种试验件进行试验验证,将原谱分别折算简化为五级谱和三级谱,折算后循环次数减少了约98%,且疲劳寿命结果符合工程要求,证明了该载荷谱折算方法的正确性和有效性。

Research and Verification on Load Spectrum Simplification of Civil Aircraft Fatigue Test

The civil aircraft full-scale fatigue test will need too long period and high cost under conventional technology,which affects the airworthiness certification and service use.Carrying out the load spectrum simplification research can effectively accelerate the fatigue test.The equivalent damage conversion method taking the threshold value of damage ratio as the conversion basis was established to simplify the load spectrum,which combining detail fatigue rating method with linear damage accumulation theory.Two kinds of bolted and riveted test pieces were selected for test verification.The original spectrum was reduced to five level spectrum and three level spectrum respectively.The number of cycles was reduced by about 98% and the fatigue life met the engineering requirements after conversion.The correctness and effectiveness of these acceleration methods are proved.