Measurement and modelling of torsional warping free vibrations of beams with rectangular hollow cross-sections

• Published in: Engineering structures Vol. 136; pp. 68 - 76
• Main Authors: Murin, Justin, Goga, Vladimir, Aminbaghai, Mehdi, Hrabovsky, Juraj, Sedlar, Tibor, Mang, Herbert A.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.04.2017; Elsevier BV
• Subjects: Beam theory (structures); Cross-sections; Deformation; Deformation effects; Finite element analysis; Finite element method; Free vibration; Mathematical models; Measurement of torsional warping eigenfrequencies; Modelling; Non-uniform torsion; Resonant frequencies; Shear stress; Structural engineering; Studies; Torsion; Vibrations; Warping; Warping eigenshapes; Warping torsional eigenfrequencies; Warping torsional eigenvibrations; Warping torsional eigenfrequencies; Measurement of torsional warping eigenfrequencies; Non-uniform torsion; Warping eigenshapes; Warping torsional eigenvibrations
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2016.12.037

•Torsional modes of the rectangular hollow cross-section beam are studied.•Measurement of torsional warping eigenfrequencies is done.•Semi-analytical and numerical modal analyses are performed.•Experimental and calculated results are compared and evaluated. This contribution contains the results of experimental measurements and modelling of torsional warping free vibrations of beams with rectangular hollow cross-sections. The experimental results are compared with results from a semi-analytical method, proposed by the authors, and from Finite Element (FE) computations by means of a standard commercial code. In these calculations, beam, solid, and shell elements are used. The semi-analytical calculations are based on the analogy between second-order beam theory, including consideration of the shear force deformation effect, and non-uniform torsion, considering the Secondary Torsion Moment Deformation Effect (STMDE). The influence of warping and of the STMDE on the torsional eigenfrequencies and eigenforms is evaluated. The difference between the measured and calculated eigenfrequencies is investigated and quantified.