Rate‐dependent stress‐strain behavior of polymeric materials

Abstract

The investigation characterizes the rate-dependent uniaxial stress–strain behavior of several polymeric materials. The characterization is done using both a mechanical model with rate-dependent elements and a general nonlinear theory of viscoelasticity. Experimental data were gathered on a Laminac polyester resin, and further data on polycarbonate and PMMA were collected from the work of Brinson. The mechanical model could be called a modified Bingham type, while the nonlinear viscoelastic theory was the single integral constitutive model proposed by Bernstein, Kearsley, and Zapas. Results from the mechanical model gave good agreement with the experimental data, the maximum difference being about 10%. The BKZ theory predictions modeled the data to within 5–12% average error.