Abstract
The viscoelastic response of amorphous polymers with mechanically induced relaxation spectra is analyzed numerically using new constitutive equations. The model combines the theory of temporary networks (in the version of a concept of adaptive links) with the Eyring concept of absolute reaction rates. Thermodynamic potentials are proposed for an incompressible viscoelastic medium at finite strains. Stress-strain relations are derived based on the laws of thermodynamics. Adjustable parameters in the constitutive equations are found by fitting experimental data for polyisobutylene in a tensile relaxation test. The model is characterized by two dimensionless parameters. One of them describes the nonlinearity in the elastic response of individual links, and the other determines the effect of the mechanical energy of crosslinks and entanglements on their breakage. The influence of these parameters on stresses in tensile loading-unloading tests and in simple shear are analyzed numerically.
| Original language | English |
|---|---|
| Pages (from-to) | 150-161 |
| Number of pages | 12 |
| Journal | Computer Modeling and Simulation in Engineering |
| Volume | 4 |
| Issue number | 2 |
| State | Published - 1 Jan 1999 |
| Externally published | Yes |
Keywords
- Amorphous polymers
- Glass transition
- Temporary networks
- Viscoelasticity
ASJC Scopus subject areas
- Modeling and Simulation
- Ocean Engineering