축-원판-블레이드 연성 계의 고유진동수 수렴특성 연구

Abstract

Shaft-disk-blade coupled systems are widely used in rotating machinery such as helicopters, windturbines, and steam turbines. In this study, an analytical model of a shaft-disk-blade coupled system isdeveloped by considering the coupling effects in shaft bending, shaft torsion, shaft shear, and bladebending. Next, the natural frequencies of the system are obtained using the assumed mode method thatemploys three types of mode functions (simple beam functions, beam functions considering the effectof lumped end-mass, and beam functions considering the effects of lumped end-mass and moment ofinertia). The results obtained by the three mode function sets are compared to those obtained using acommercial FE program, and the natural frequency convergence characteristics are discussed. It wasfound that only one of the mode function sets guaranteed accurate natural frequency convergence.