EFFECT OF STEP LOADING ON THE LINEAR AND NON-LINEAR VISCOELASTIC BEHAVIOR OF SOLID POLYMERS USING FEM

Problems of step loading in one and two dimensions were investigated using FEM. 2D FE program was modified to study the linear and non-linear viscoelastic strain using non-linear viscoelastic model “Schapery’s model” as constitutive low along with spectrum of material properties. A very carefully selected four case studies covering an important part of viscoelastic behavior were solved for two types of solid polymers, Polyurethane and Poly (vinyl chloride). An excellent fit was obtained when comparing the predicted results with those obtained experimentally.