The only parameters the values of which are not known from nature are those governing the elastic (v) and damping properties of the body tissues (McMillen et al., 2008).
A mean tissue modulus for each vertebral body was then back-calculated from the experimental stiffness using a 12 μm resolution, homogeneous, linear elastic (v = 0.3) finite element model of the same loading scenario.
The choice of model-based C is explained by the fact that it is linked to elastic properties (V p and V s) through rock physics model of Han et al. (1986).
Fig. 3 Stress vs strain for S30C specimen Fig. 4 Ratio of change in propagation velocity of elastic wave vs stress for S30C L long specimen, S:short specimen.
c The internal fluid is replaced by an elastic body V in consisting of the same elastic material as the external medium.
In this case, we replace the material inside the cavity with an elastic body V in with surface Σ in that has the same mechanical properties as the surrounding elastic body and the same shape as the cavity.
The corresponding displacement on Σ in is ({u_{i}^{I}}), which is different from the actual displacement on Σ. d The internal fluid is replaced by an elastic body V in consisting of the same elastic material as the external medium.
First, we replace the material inside the cavity with an elastic body V in with surface Σ in that has the same mechanical properties as the surrounding elastic body and the same shape as the cavity.
V2 variation of the potential energy of the drill string as a result of elastic deformation: V 2 = E A 2 · ∫ 0 L ∂ u ∂ z 2 d z = k 2 · ( x - y + f ) 2 (8).
Following Watada (2009), we define the transfer function as, where ω is the angular frequency, p the pressure perturbation, ρ the density of the elastic media, V s the shear wave velocity of the elastic media, and the vertical ground velocity.
According to the equation E = ρV2 (E = Elastic modulus, V = Shear velocity, ρ = mass density), the stiffer the tissue is, the faster the wave can pass through it.
