Análise Dinâmica da Fuselagem Posterior de uma aeronave de asa rotativa

Abstract

A problem that a long time worries the Brazil Navy maintenance personnel is the wrinklement of the tail boom of helicopters UH-12 (single turbine) and UH-13 (double turbine). This problem occurs mainly due to dark landing, accidental crash or during the maintenance service. The repair of a damage characteristic of wrinkle is done by maintenance hangar personnel, but, there isn’t a technical support that establishes a limit to repair dimensions to be done, so that to preserve the frequencies and modes of vibration of tail boom and not reduce its structural stiffness. This work has the purpose to determine the structural stiffness and the mains frequencies of vibration of the tail boom, from these helicopters, using the finite element method. For to reach this purpose, a tail boom structural model has been processed (the two helicopters have the same structural tail boom), using Nastran Software. Two kinds of common damage have been simulated in structural model, similar of true damage. The structural repair impact on modes and frequencies of vibration of this tail boom helicopters has been analyzed, taking into consideration, the variation on centre of gravity and the mass of structure. This work has the purpose of to help in technical support to repair done by Sao Pedro D’Aldeia Air Naval Base Maintenance Division.