Moving load response of an axially loaded Timoshenko beam on a multilayered transversely isotropic half‐space comprising different media

• Published in: International journal for numerical and analytical methods in geomechanics Vol. 44; no. 18; pp. 2501 - 2523
• Main Authors: Li, Yi‐Cheng, Feng, Shi‐Jin, Chen, Zhang‐Long
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.12.2020
• Subjects: alternate distribution; axial force; Axial forces; Deflection; Domains; Dynamic response; Fourier transforms; Isotropy; moving load; Moving loads; multilayered foundation; Permeability; Permeability coefficient; Phase velocity; Pore pressure; Pore water; Pore water pressure; Propagation modes; Shear modulus; Soil; Soil moisture; Soil permeability; Soil properties; Stiffness matrix; Thermal expansion; Timoshenko beam; Timoshenko beams; transversely isotropic; Vibrations; Wave propagation; Wavelengths
• ISSN: 0363-9061; 1096-9853
• DOI: 10.1002/nag.3155

This paper investigates the dynamic response of an axially loaded Timoshenko beam coupled with a multilayered transversely isotropic (TI) half‐space subjected to a moving load. An axial force induced by the thermal expansion is taken into account in the Timoshenko beam. The half‐space considers the alternate distribution of an arbitrary number of TI elastic and poroelastic layers to model foundation soils with different properties and moisture conditions. To solve the governing equations, Fourier transform is adopted. The stratified foundation is formulated by extending an “adapted stiffness matrix method” to a more general scenario with an arbitrary number of layers. The beam is then coupled with the foundation to derive solutions to the system in the frequency‐wavenumber domain. The final results in the time‐spatial domain are recovered by the inverse Fourier transform. After confirming the accuracy of the method in this study, the influences of the pore water existence, the transverse isotropy of different parameters, and the axial force are investigated. It can be observed that the effect of pore water existence on the maximum beam deflection can reach 22% in this study. The transverse isotropy of the elastic and shear moduli influences the critical speed of the beam deflection by altering the phase velocity of the first wave propagation mode of the beam‐foundation system. The vertical permeability coefficient is more important than the horizontal one in determining the excess pore pressure. The rise of the beam temperature (axial force) decreases the critical speed and magnifies the vibrations.