Dynamic analysis of helicoidal bars with non-circular cross-sections via mixed FEM

Eratlı N., Yılmaz M., Darılmaz K., OMURTAG M. H.

Structural Engineering and Mechanics, vol.57, no.2, pp.221-238, 2016 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 57 Issue: 2
  • Publication Date: 2016
  • Doi Number: 10.12989/sem.2016.57.2.221
  • Journal Name: Structural Engineering and Mechanics
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.221-238
  • Keywords: Mixed finite element, Non-circular cross-sections, Non-cylindrical helix, Poisson's equation, Torsional moment of inertia
  • Istanbul Medipol University Affiliated: Yes


One of the objectives of this study is to implement the direct calculation of the torsional moment of inertia for non-circular cross-sections, which is based on the St. Venant torsion formulation and the finite element method. Recently the proposed method provides a unique calculation of the torsional rigidity of simply and multiply connected cross-sections. Next, free vibration analyses of cylindrical and non-cylindrical helices with non-circular cross-sections are solved by a curved two-nodded mixed finite element based on the Timoshenko beam theory. Some thin-thick closed or open sections are handled and the natural frequencies of cylindrical and non-cylindrical helices are compared with the literature and the commercial finite element program SAP2000.