Letter to the editor
Résumé
Comment on the paper: A. M. Yu,Y. Hao, Improved Riccati transfer matrix method for free vibration of non-cylindrical helical springs including warping, Shock and Vibration, Volume 19, number 6, 2012, pp. 1167–1180, DOI 10.3233/SAV-2012-0677 I would like to point out that this paper contains an error in the parametrization of the helix. It is easy to understand why the authors made this mistake as the parametrization and examples used in this work appear in previously published articles that mostly suffer from the same deficiencies.