The Nonlinear Dynamics Research About The Rotor System Which Contains Blade Crack Of The Turbo-machine

The rotor system is the core part of the fan, it shoulders the important task which change the electrical energy into the mechanical energy. When the rotor works, the condition of the stress is complex, also the condition of runner working is bad in practical, these stabilize and unstable factor brings dissolute-exciting force and metabolic change centrifugal force, which will make the blade libration, the long time vibrancy causes the machine constructure's endurance failure, because of it the dynamic stress comes out ,which become the important reason the blade having crack.In this article, the blade root (blade and axis's joint) appears crack, so that the blade and the axletree create un-conventional vibration and other unusual phenomena, launches the research work. To found the nonlinear dynamic control equation of the plate-axis rotor system which to have the viscoelasticity bearing in the general situation, then analyzed its stability. It founded the linearity spring model of the rotor system that has the cracked blade, then educed the partial flexibility coefficient of the cracked blade. Also with the finite element software, to analyze the rotor axletree's displacement, the distribution and size of equivalent stress,which bearing the cracked blade unbalanced force ,besides present the corresponding relational graph. After accounted the stress distributing and the axial displacement of certain type blade, through the analysis stress - function of time curve of the blade, obtained the conclusion that concentration of stress to speed up the expansion of the crack . At the same time, analyzed the many kinds of factors of the blade breaking and crack , then proposed some correlation suggestions to avoid appear similar phenomenon.