Abstract: “In this study, the effects of viscous bulk compressibility on the dynamic viscoelastic response of noncylindrical helicoidal rods are examined. For this aim, a viscoelastic model is proposed that takes standard type of distortional behavior and Kelvin type of bulk compressibility. Based on Timoshenko beam theory, two-nodded curvilinear elements are in Laplace space. The viscoelastic material properties are implemented into the formulation through the use of the correspondence principle (elastic-viscoelastic analogy). The analysis is carried out in the Laplace space and the results are transformed back to time space numerically by using the modified Durbin's algorithm. As sample problems, the noncylindrical helicoidal rods fixed from both ends which are subjected to dynamic step type of distributed loading are considered. Three different helicoidal rods that have different helical geometries are analyzed and their dynamic responses are compared. The effects of viscous bulk compressibili”

Keywords: viscoelasticity, noncylindrical helicoidal rod, mixed finite element method, Laplace space