Modeling the large-strain constitutive behavior of polycarbonate under isothermal and anisothermal conditions

✍ Scribed by J. Sweeney; P. Caton-Rose; P. D. Coates

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 265 KB
• Volume: 96
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/app.21681

✦ Synopsis

The tensile behavior of polycarbonate was studied at large strains below the glass-transition temperature. Experiments were carried out at a series of constant temperatures and also under conditions of falling temperatures. The specimens necked with a natural draw ratio of approximately 2, and the study was mainly focused on the necked material. Isothermal experiments revealed an elastic mechanism that initiated beyond the natural draw ratio. A model consisting of an Eyring process and two Gaussian elastic mechanisms was found to be applicable to both the isothermal and anisothermal stress-relaxation and stressstrain results. The same model also produced reasonable estimates of the stresses generated during the necking process. In addition, a simple relationship between the isothermal and anisothermal stress relaxation was demonstrated.