Experimental and Numerical Analysis of Triply Coupled Vibration of Thin-Walled Beam with Arbitrary Closed Cross-Section

In this paper, a numerical experimental study about coupled vibration and natural frequency of thin-walled beams with an arbitrary closed cross-section is presented. A new thin-walled beam dynamic transfer matrix method, named TDTMM, is presented in the frequency domain for the thin-walled beam, which expands the advantages of the general dynamic transfer matrix method (GDTMM). The theory takes into account the influence of warping effect, that is, both the bimoment B and the rate of twist phi(x) of the beam are considered, and the TDTMM is derived by solving the governing differential equations of motion for coupled bending and torsional vibration of the thin-walled beam. Finally, two numerical examples and one experimental example are given and compared with the GDTMM and the finite element method (FEM) results to validate the developed theory.