民用飞机客舱窗对机身扭转刚度的影响

The Effect of Window on the Torsion Stiffness of Fuselage in Civil Aviation

在民用飞机的设计阶段,需要对整机进行模态分析,而如何准确地得到机身、机翼等主要结构部件的刚度数据就显得尤为重要。工程上一般采用闭室结构的刚度计算方法计算各截面刚度,并在此基础上对某些特殊截面的刚度进行修正。为了能让修正后的结果更加接近实际情况,有必要对客舱窗、登机门以及货舱门等局部开口对截面刚度的影响进行研究。本文借助有限元软件PATRAN/NASTRAN,对机身有限元模型进行加载,根据变形结果反推截面的扭转刚度,并将此得到的扭转刚度与闭室结构的计算结果进行比较。通过比较发现,客舱窗对机身扭转刚度有较明显的影响,为工程计算中的修正提供了参考。

At the designing stage of civil aviation, the mode analysis of the airplane is necessary. As a re- sult, the accurate stiffness data of the main structures such as the fuselage and the wings become really important. In the engineering field, a close-structure method is often adopted to calculate the stiffness of each section. The stiffness of a special section is modified if necessary. In order to make the modified data close to the practical situation, it is essential to study the effect of local gap such as window, passenger door and cargo door on the stiffness of each section. A finite element （FE） analysis was carried out by PATRAN/NASTRAN. The FE model of the fuselage was loaded, and the torsion stiffness was calculated according to the deformation of the fuselage. The calculated torsion stiffness was compared with the stiff- ness obtained by the close-structure method. It was found that the window had obvious influence on the torsion stiffness of the fuselage.