Author(s)

S.M. Hashemi & A. Roach

Abstract

The free vibration analysis of coupled extension-torsion structural members is addressed. The derivation of a Dynamic Finite Element (DFE) for a uniform structural member is presented. Exploiting the uncoupled member theory, the Dynamic Trigonometric Shape Functions (DTSFs) are derived. The application of the Weighted Residual Method and DTSFs results in the element stiffness matrices. Solving the resulting global eigenproblem of the system, one can then evaluate the natural frequencies and modes of vibration of the structure. The coupled extensional-torsional free vibration of a helical spring is studied. Comparison between natural frequencies obtained from FEM and DFE revealed that for higher frequencies the DFE approach leads the significantly higher convergence rates. Therefore, the

Keywords