Dear FEAP Admin,
When simulating wave propagation in viscoelastic material, I found somewhat strange phenomenon.
In the 2D plane strain plate, a square wave (5Mhz, 100cycle) is generated by exerting nodal force on the middle position of the top side of the plate.
And then, I compared elastic model and viscoelastic (mu1 = 0.5, tau1 = 1e-6) model.
However, as the Poisson's ratio closes to 0.5, the difference between elastic model and viscoelastic model disappears.
I compared displacements in the y direction of 2 cases (nu=0.49, nu=0.4999996).
In the first case of nu=0.49, viscoelastic model shows larger displacement compared to elastic model.
However, in the second case of nu=0.4999996, any difference was not observed.
All the models have the same P-wave speed (1500m/s) and geometry condition, by changing Poisson's ratio (nu=0.49, nu=0.4999996) and Young's modulus (E=131471000, E=5400).
Aim to change Young's modulus is to set the wave speed in each case to the same value.
In summary, I have some trouble understanding the reason that the displacement in the first case is different while in the second one there is no different.
Input files are attached.
Could you please let me fix the problem?
Best regards,
Jae-Wook Jung.
