Abstract：Based on the theory of saturated porous media, a mathematical model for dynamics of the transversely isotropic saturated poroelastic Timoshenko beam is established with assumption that fluid in pores moves only in the axial direction of the beam. Under some limiting cases, this mathematical model can be degenerated into Euler-Bernoulli Model, Rayleigh Model and Shear Model of the poroelastic beam respectively. With the mathematical model presented, the natural frequencies and attenuations for free vibration and the dynamical behavior of the simply-supported poroelastic Timoshenko beam, with two ends permeable and subjected to the step load are investigated. The variations of the deflections, bending moments of the poroelastic beam and the equivalent couples of the pore fluid pressure are shown in figures and are compared with the results of the simply-supported poroelastic Euler-Bernoulli beam. The influences of the interaction coefficient between the solid skeleton and the slenderness ratio of the beam are discussed. It is shown that the interaction coefficient plays a role as viscidity. The amplitudes of deflection attenuate more rapidly with the increasing of the interaction coefficient, and the deflection approaches to that of the static response. Furthermore, the deflection amplitude and period of the poroelastic Euler-Bernoulli beam are smaller than those of the poroelastic Timoshenko beam, and the limit values of the bending moments are the same for the poroelastic Euler-Bernoulli beam and Timoshenko beam.
2010, Vol. 31 
