Hi,
I am aiming to predict Permanent deformation and/ relevant parameters for multilayer pavement systems.
using step type:visco, loading: Cyclic tire pressure (0.8 MPa) applied via a periodic Haversine amplitude (40 km/h simulation).
 Asphalt layer: Power Law Creep (TIME) with A=1.5e-08, n=1.9 and m=-0.18. Elastic Modulus \\\$E=1800 (tried 1000 as well MPa). All other layers are modelled as purely elastic.Interactions (TIE) .Boundary Conditions: Symmetry on sides, Encastre at the bottom.
The Question is:
 Why is my pavement creep model failing to accumulate permanent deformation (rutting)? (U2) results show only elastic oscillation (approx. 0.3mm). The displacement returns almost to the baseline in every cycle, and I am seeing no accumulation of permanent strain (rutting) over time.The CEEQ values are small with no significant growth.
Is the elastic base layers below the asphalt layer preventing creep accumulation?.
Please advise..?