Authors: Vebil YILDIRIM, Nilgün İNCE
Abstract: The free vibration problem of non-cylindrical helical springs such as hyperboloidal, barrel and conical is studied by the stiffness method considering the effects of rotary inertias, axial and shear deformations. The cylindrical helical element stiffness matrices with twelve degrees of freedom, which are obtained numerically by the transfer matrix method, are employed in the formulation. The consistent element mass matrices of spatial straight element are also implicated in the analysis. The general eigenvalue problem is solved by the subspace iteration and Jacobi's methods. After verifying the results obtained, effects of the number of active coils, the helix pitch angle, the ratio of diameters of minimum cylinder to maximum cylinder, the ratio of diameters of w we to maximum cylinder, and circular and rectangular sections on the free vibration frequencies are investigated.
Keywords: Helical Spring, Vibrational Parameters, Natural Frequency, Free Vibration, Non-Cylindrical