Experimental and theoretical investigation of a polymer subjected to cyclic loading conditions

There are many machine components made of polymeric materials, such as gears, which are subjected to cyclic loading conditions. To design such components, it is necessary to arrive at a suitable mathematical model that can describe the mechanical response of polymeric materials. In this paper, we derive a mathematical model for rate-type solids using thermodynamical framework developed by Rajagopal and Srinivasa (K.R. Rajagopal, A.R. Srinivasa, A thermodynamic frame work for rate type fluid model, Journal of Non-Newtonian Fluid Mechanics 88 (2000) 207–227) (also see Section 5 of Kannan and Rajagopal (K. Kannan, K.R. Rajagopal, A thermomechanical framework for the transition of a viscoelastic liquid to a viscoelastic solid, Mathematics and Mechanics of Solids 9 (2004) 37–59)), which was used by Rajagopal and Srinivasa to derive a mathematical model for isotropic, rate-type liquids. Uniaxial cyclic loading and stress relaxation experiments were conducted. The predictions of the model agreed well with the experimental data.