Creep analysis of visco-hyperelastic non-uniform rotating disks

This research investigates the creep phenomenon of a polymeric rotating disk using the generalized Maxwell’s visco-hyperelastic model. After extracting the Lagrangian partial differential equation of equilibrium governing the problem, the rotating disk was analyzed by scripting in FlexPDE. The disk modelling in ANSYS with coding in the APDL environment showed that the radial displacement and Von-Mises stress are in excellent agreement with the FlexPDE results. The advantages of FlexPDE over ANSYS include one-dimensional analysis of axisymmetric plane stress instead of two-dimensional analysis, reduction of computational cost, possibility of defining variable thickness (without additional coding) and need for fewer elements in the radial direction to achieve acceptable accuracy (necessity of using 20 elements in FlexPDE compared to 100 elements in ANSYS). It was shown that with the passage of time and the increase in angular velocity, the radial displacement and Von- Mises stress of the rotating disk due to the creep phenomenon increase. It was shown that by increasing the angular velocity and decreasing the power in the thickness profile n_h, the displacement and Von-Mises stress at a specific time increase, but the change in angular velocity (as the applied load) and the change in parameter n_h (as a geometric characteristic) do not have much effect on the relaxation time of the rotating disk.