阵风载荷谱的损伤分散性研究

Load spectrum variation matters to fatigue reliability service life of a fleet. For transport aircraft, gust load is one of the critical damage sources. To study the damage variation of gust load spectra, two parts have been investigated. In the first process, gust velocity exceedance measured in service of several transport aircraft are statistically analyzed based on discrete-gust model. It is assumed that incremental exceedance of specific gust velocity follows lognormal distribution, and a model of gust velocity exceedance variation is built. In the second process, the damage variation of gust load spectra is studied. With the help of Monte Carlo simulation, gust velocity exceedance curves of aircraft in a fleet are acquired, after which damage of gust load spectra can be calculated. To examine the validity of the methodology, numerical examples are calculated, in which flight profiles of 3 specific transport aircraft are used. The results show that damage variation of gust load spectra of transport aircraft follows lognormal distribution and the values of scatter factor are relevant to flight profiles.