Propagation and localization of wave in multi‐span Timoshenko beams on elastic foundations under moving harmonic loads

• Published in: International journal for numerical and analytical methods in geomechanics 2017-12, Vol.41 (17), p.1687-1710
• Main Authors: Ding, L., Wu, L., Zhu, H.‐P.
• Format: Article
• Language: English
• Subjects: Beams (structural); Constants; Coordinate systems; Critical velocity; Deformation; disorder; Finite element method; Loads (forces); Localization; moving harmonic load; multi‐span beam; Periodicity; Propagation; Timoshenko beams; Velocity; wave localization; Wave propagation
• ISSN: 0363-9061; 1096-9853
• DOI: 10.1002/nag.2693

Summary Wave propagation and localization in ordered and disordered multi‐span beams on elastic foundations due to moving harmonic loads are investigated by using the transfer matrix methodology. The transfer matrix, as a function of the frequency and velocity of the moving harmonic load, of the periodic beam is formulated in a coordinate system moving with the load. The expressions of critical velocities, cut‐off frequency of an associated uniform beam without discrete spaced supports, are determined through the analysis of the wavenumbers, and the dynamic responses of the beam are also examined. For the ordered and disordered case, the propagation constants and localization factors are respectively employed to identify the velocity and frequency pass bands and stop bands in order to examine whether the perturbation can propagate along the structure or not. The effects of the periodicity, disorder level, excitation frequency, and moving velocity are studied in detail. The validity of the obtained results is confirmed by evaluating the transverse deformation of the beams through the finite element simulations. Copyright © 2017 John Wiley & Sons, Ltd.