Dynamic Behavior of Two-Layered Beam Subjected to Mechanical Load in Thermal Environment

The research investigates a composite beam consisting of two layers with different thicknesses and materials subjected to thermal and mechanical loads. Two cases of temperature loading are considered here: uniformly distributed temperature along the whole beam and linear distributed temperature along the beam thickness. A reduced model of the problem based on the first three beam’s normal modes is formulated. Additionally, a simplified one-mode reduction model is developed and solved analytically by the harmonic balance method (HBM). A comparison between the results of the three-mode reduction and the one-mode reduction models highlights the applicability and limitations of the latter. Differences in the resonance curves produced by these models are thoroughly examined. The reduced models are validated through comparison with results obtained by FEM. The detailed bifurcation diagrams are presented for the reduced three-degree-of-freedom (3-DOF) model. The analysis reveals phenomena such as loss of stability, mode interaction, buckling, and chaotic oscillations. These findings provide deeper insights into the dynamic behavior of thin composite beams subjected to mechanical and thermal loads, considering different variations of the temperature distribution.