民用飞机弹性结构水上迫降试验载荷研究

Research on Civil Aircraft Elastic Structure Ditching Test Load

刚体模型和弹性体模型的载荷传递方式不同,为了研究刚体模型和弹性结构模型对飞机水上迫降载荷的影响,根据动力相似性原理设计制造了刚体模型,并根据强度相似性原理设计制造了弹性结构部件,通过气囊加载试验系统验证了弹性结构部件满足强度相似设计要求。通过水上迫降模型试验测得加速度-时间历程曲线,使用傅里叶变换处理试验数据得到加速度峰值。根据刚体模型的试验数据分析,飞机以初始俯仰角12°、襟翼为着陆构型、较小的下沉速度和中重心状态入水时,飞机在水上迫降过程中受到的载荷较小。研究表明:带弹性结构模型和刚体模型所得到的飞机载荷有明显的不同,带弹性结构模型得到的垂向加速度峰值明显低于刚体模型。这种现象主要是由于机体着水底部弹性结构变形吸收了大量的能量。

Load transfer is different between rigid model and elastic structure model. In order to research the impact of rigid model and an elastic structure model on ditching loads, a rigid model is designed and manufactured, based on the principle of dynamic similarity and the elastic structural part is designed and manufactured based on the principle of strength similarity, which is validated by an airbag loading test system. Through the ditching model tests acceleration-time history curves are obtained and peak acceleration value is obtained by processing the experimental data with Fourier transform. According to the rigid model experimental data analysis, the aircraft is subjected to a relatively small load in ditching with the following parameters： pitch 12°, flaps in landing configuration for minimum speed and middle center of gravity. The results indicate that the load is obviously different on the model with an elastic structural part and on the rigid model. The peak value of verti- cal acceleration of the model with elastic structure part is obviously smaller than that of the rigid model. This phenomenon is mainly due to energy absorption by the bottom elastic structure of fuselage.