HCF Life Research On Main Rotor Shaft Of Helicopter

Main rotor shaft is a critical part in helicopter transmission system and its reliability has a direct influence to flight safety. Fatigue test of main rotor shaft must be identified according to the type criterion because of the shaft suffer complicated loads including axis force, moment, share force and torque form rotor in real flight state. The setting boundary conditions of part in real state and influence of outer factors as material and process technical to the life of part are hard to considered and simulated, so it is difficult to get the using life only by theory analysis and compute. Combined finite element theory analysis and fatigue test by multi channels loading coordinately in this paper, get the high-cycle fatigue life of one main rotor shaft by high-cycle fatigue test of test parts and provide an effective solve method to the fatigue life of the shaft part in transmission system.Study results as follows:(1) applied the technology of composite and revolving loads in this research, achieved a full-load fatigue test of main rotor shaft and a gap to this kind test technology has been supplied;(2) the danger parts of main rotor shaft have been confirmed by finite element method, then adopted the whole rigid design method according to stress distributing, the test for main rotor shaft fatigue life research has been designed effectively and two high-cycle fatigue tests have been carried out successfully;(3) all strains of main rotor shaft have been measured accurately by combine testing method to the typical part, the test design approved to be effectively according to the contrast of test results and finite element compute results and confirmed the conclusion that main rotor shaft has a10000h life finally.