Bending–torsional coupled dynamic response of axially loaded composite Timosenko thin-walled beam with closed cross-section

Abstract

An analytical method is presented to determine the bending–torsion materially coupled dynamic responses of axially loaded composite thin-walled beam with solid or thin-walled closed cross-section subjected to various kinds of concentrated and distributed time-dependent loads. The effects of axial force, shear deformation and rotary inertia are included in the present study. The bending–torsion material coupling of practical interest is also considered in the formulations. First, the general governing differential equations of motion of axially loaded composite Timoshenko beam are developed and the free vibration analysis is performed. Once the natural frequencies and mode shapes of the composite beam are obtained, normal mode method is used to compute the bending–torsion coupled dynamic response of axially loaded composite Timoshenko beam. Finally, the proposed method is illustrated by its application to a particular example to investigate the effects of bending–torsion coupling, axial force, shear deformation and rotary inertia on the dynamic behavior of composite beam.