Vibrations of Pre-Twisted Cantilever Blading

摘要: This paper reports a study of the vibrations pre-wisted cantilever blading. The blading is pre-twisted linearly about centroid its cross-section up to an angle π/2 rad and considered be mounted encastre at root. Accurate prediction frequencies vibration such considerable practical importance.Two theoretical approaches problem are discussed. first one, involving direct solution equations motion, not made use of, although characteristic derived in appendix for reference. second approach based on application Rayleigh's principle. For blades uniform rectangular cross-section, frequency fundamental mode lateral motion all modes torsional motion. Similar types equation shown apply aerofoil cross- section since coupling effects between bending torsion, being extremely small, can neglected.Vibration tests were conducted ...