Nonlinear dynamics of a tubular beam considering distortion of the cross sections and internal resonances

Abstract The nonlinear dynamics of a thin tube under the action harmonic external load is addressed in paper. Use made beam-like model which extends Timoshenko beam with further kinematic descriptors, related to change shape cross section. applied half cap pipe, directly triggering both bending axis-line and flattening sections. equations motion are projected on reduced basis constituted by first three linear modes, then solutions sought via multiple scale method, for two different resonance conditions. Internal resonances among modes considered as well. outcomes, compared pure numerical solutions, highlight possible energy exchange between local i.e., those describing warping sections, global rotation section pipe.