Dynamic response of an axially loaded bending-torsion coupled beam

Abstract

A method is presented to predict the response of an axially loaded beam coupled in bending and torsion to deterministic and random loads. The beam is uniform and is assumed to carry a constant axial load. It is subjected to time-dependent bending and/or torsional load, which can be either deterministic or random. Both concentrated and distributed loads are considered. The deterministic load is assumed to vary harmonically, whereas the random load is assumed to be Gaussian, having both stationary and ergodic properties. The theory developed is applied to a cantilever wind turbine blade for which there is substantial coupling between the bending and torsional modes of deformation. Numerical results are presented and the effect of axial load on dynamic flexural and torsional displacements is discussed.