where Aij^4x is a function only of the modal response parameter Sqj. This equation can also be written 

 in the form 



Y^MAxM/D = AMAxiSG.i)I~'\'i'iix)\ (D19) 



where Axiax 'S the maximum response amplitude for a rigid, spring-mounted cylinder (t//, = 1, xjj i^\ = 



0) having a cross-section similar to the elastic cylinder. Here the notation for the multiplicative factor 



/,,„ is simplified to /,. The parameters F,, G,, //, in equations can be obtained from equations (D9) 



when the modal response parameter Sq , = C JfJ^ a is known. Then not only the amplitude response but 



also such system features as the lift response and phase between the lift force and structural motion can 



be obtained from equations (D16), as demonstrated in detail elsewhere (DIO). Additional discussion 



of the wake-oscillator approach can be found in a recent textbook on wind engineering by Simiu and 



Scanlan (Dll), the proceedings of a recent international conference on wind engineering (D12), and in 



the discussions of a recent colloquium on vortex shedding from bluff bodies (D13). 



References 



Dl. R.E.D. Bishop and A.Y. Hassan, "The Lift and Drag Forces on a Circular Cylinder in a Flowing 

 Fluid," Proceedings of the Royal Society of London, Series A, Vol. 277, pp. 31-75, 1964. 



D2. R.T. Hartlen, W.D. Baines and I.G. Currie, "Vortex-Excited Oscillations of a Circular Cylinder," 

 University of Toronto Technical Report 6809, 1968. 



D3. R.A. Skop and O.M. Griffin, "On a Theory for the Vortex-Excited Oscillations of a Flexible 

 Cylindrical Structure," Journal of Sound and Vibration, Vol. 41, pp. 263-274, 1975. 



D4. O.M. Griffin and R.A. Skop, "The Vortex-Induced Oscillations of Structures," Journal of Sound 

 and Vibration, Vol. 44, pp. 303-305, 1976. 



D5. W.D. Iwan and R.D. Blevins, "A Model for the Vortex-Induced Oscillation of Structures," Tran- 

 sactions of ASME, Journal of Applied Mechanics, Vol. 41, pp. 581-585, 1974. 



158 



