Modelling nonlinear viscoelasticity and damage in amorphous glassy polymers

✍ Scribed by A.D. Drozdov

• Publisher: Elsevier Science
• Year: 2001
• Tongue: English
• Weight: 731 KB
• Volume: 33
• Category: Article
• ISSN: 0895-7177
• DOI: 10.1016/s0895-7177(00)00287-9

✦ Synopsis

Abstract+onstitutive

equations are derived for the nonlinear viscoelsstic behavior of amorphous glassy polymers in the subyield region, A polymer is thought of as an ensemble of cooperatively rearranged regions trapped in cages. In the phase space, a cage is modeled ss a potential well, where a flow unit hops ss it is thermally activated at random times. The viscoelastic response ls treated as rearrangement of flow units. A rearrangement event occurs when a region reaches some liquidlike state in a hop. Damage of a polymer is modeled as breakage of van der Waals forces between monomeric units. It happens when the nominal strain in a relaxing region exceeds some threshold level. Stress-strain relations for a glassy polymer and a governing equation for the damage evolution are develo,ped and verified by comparison with experimental data. Fair agreement is demonstrated between results of numerical simulation and observations for polycarbonate.