Akademik Veri Yönetim Sistemi
MECHANICS OF COMPOSITE MATERIALS AND STRUCTURES, cilt.8, sa.3, ss.205-217, 2001 (SCI-Expanded)
The first six resonance frequencies of unidirectional composite noncylindrical helical springs (barrel and hyperboloidal types) made of carbon-epoxy (T300/N5208) material are determined theoretically based on the transfer matrix method The rotary inertia, shear, and axial deformation effects are considered with the first-order shear deformation theory. The overall transfer matrix is obtained by integrating the 12 scalar ordinary differential equations with variable coefficients governing the free-vibration behavior of noncylindrical helical springs made of an anisotropic material. Numerical results are verified with the reported values for isotropic noncylindrical helices. A parametric study is performed to investigate the effects of the number of active coils (n = 5-10), the helix pitch angle (alpha = 5 degrees and 25 degrees), the ratio of the minimum to maximum cylinder radii (Rmin/Rmax = 0.1 and 0.9), and the ratio of the maximum cylinder diameter to the wire diameter (D-max/d = 5 and 15) on the free-vibration frequencies of constant-pitch composite barrel and hyperboloidal helical springs with circular sections and fixed-fixed ends.