Analytical Responses Of Civil Airplane To Gust In Control Surface Swing

Gust load is the load of the airplane which is flying in the unstable atmosphere, and it is anadditional load which is caused by the air turbulence. Gust load is a very important parameter forairplane strength design. In this thesis, a method for analyzing the response of airplane in controlsurface swing to gust has been established, based on the CFD combined MSC.Nastran software. Astructural finite element model of the airplane was established by the MSC.Nastran for the modalanalysis of the airplane. The responses of the airplane in no control surface swing to gust werecalculated. Because the MSC.Nastran cannot calculate the gust response of airplane in control surfaceswinging, a new method has been established in this thesis. First, an aerodynamic model is establishedby CFD, and the gust loads acting on the airplane in control surface swinging are calculated by CFD.Then the gust loads are imported into the structural finite element model in the MSC.Nastran. Thetransient response in time domain of the airplane to the gust loads are calculated by the MSC.Nastran.Finally, the transient responses in time domain of the airplane to the gust are transformed into thefrequency domain. The comparisons of the results calculated by the MSC.Nastran and by the CFDcombined MSC.Nastran were in good agreement, indicating that the method established in this thesisis reasonable and feasible. By using the method established in this thesis, the gust responses of theairplane in the ailerons swinging to an angle, the ailerons oscillating swinging and spoilers swingingto an angle were calculated and the peak loads of different point stations were also calculated.