Effects of weak nonlinearity on the dispersion relation and frequency band-gaps of a periodic Bernoulli-Euler beam.
The paper deals with analytically predicting the effects of weak nonlinearity on the dispersion relation and frequency band-gaps of a periodic Bernoulli-Euler beam performing bending oscillations. Two cases are considered: (i) large transverse deflections, where nonlinear (true) curvature, nonlinear material and nonlinear inertia owing to longitudinal motions of the beam are taken into account, and (ii) mid-plane stretching nonlinearity. A novel approach is employed, the method of varying amplitudes. As a result, the isolated as well as combined effects of the considered sources of nonlinearities are revealed. It is shown that nonlinear inertia has the most substantial impact on the dispersion relation of a non-uniform beam by removing all frequency band-gaps. Explanations of the revealed effects are suggested, and validated by experiments and numerical simulation.
Department of Mechanical Engineering, Technical University of Denmark, Nils Koppels Allé, Building 404, 2800 Kongens Lyngby, Denmark; Institute of Problems in Mechanical Engineering RAS, V.O., Bolshoj pr. 61, St Petersburg 199178, Russia.
Vladislav S
0000-0003-4457-7066
VS
Sorokin
Department of Mechanical Engineering , Technical University of Denmark , Nils Koppels Allé, Building 404, 2800 Kongens Lyngby, Denmark.
Jon Juel
JJ
Thomsen
dispersion relation; elastic wave propagation; frequency band-gaps; method of varying amplitudes; periodic Bernoulli–Euler beam; weak nonlinearity