THE ANALYSIS OF LAMINATE LAY-UP EFFECT ON THE FLUTTER SPEED OF COMPOSITE STABILIZERS

摘要

This paper presents an analytical study onthe effect of laminate lay-up of composite missilestabilizer structure for achieving a maximumflutter speed without strength penalty.The flexible stabilizer structure in high–velocity flow may experience flutter, anaeroelastic phenomena where vibrations of thestructure become unstable and can cause stabilityloss and flight vehicle failure. Flutter in missilesis mainly affected by the aerodynamic andstructural properties of the stabilizers whereasflight vehicle body has a minor role.In the present paper the effect of laminatelay-up on flutter speed of composite missilestabilizers is investigated. Two degrees of freedom(plunge and twist) analytical model of typical finstabilizer airfoil section is presented. Based onthis model the critical flutter speed for thecomposite missile stabilizer is derived forsubsonic flight conditions. It was found thatnatural stabilizer frequencies (in bending andtwisting) highly influence the maximum flutterspeed. Natural fin frequencies (in bending andtwisting) are calculated using finite elementapproach based on Lanczos method offrequencies extraction. Several modal frequencymodels are investigated and results are discussed,since the accurate prediction of naturalfrequencies plays significant role in overall flutterspeed (VF) determination. For the trapezoidalstabilizer shape different laminate lay-upsequences are investigated, flutter speedscalculated and results compared in order todetermine maximum flutter speed. The material ofinterest in this study was carbon based AS/4 -3501-6..