关键词: 直升机, 桨叶, 扬起下坠, 碰撞, 响应

Abstract: In order to investigate the dynamic characteristics of blade impact to droop stop, a moderate deflection beam model is adopted to deal with the elastic deformations, and the finite rotation is introduced to take account of the rigid motions around hinges. Dynamic equations of blade droop stop impact are derived by Hamilton principle. Implicit-Newmark method is used to compute the dynamic response when blade is released with an initial flap hinge angle. Comparison of computation with test shows that the fixed step method results in time delay with test data and the computation time is much longer. To solve this problem, impact buffer area is inserted just before the impacting occurs. When jumping over this area, computation must go through this area by alterable steps. This method can solve the delay problem and computation time is reduced a lot. The results are in good agreement with the test data.

Key words: helicopter, blade, droop stop, impact, response