- Amorphous solid (glassy) polymers are widely utilized e.g. in engineering components of vehicular and aeronautic systems. - Applications are due to high chemical resistance, good reforming properties, and a preeminent combination of toughness and strength under cyclic and impact loadings. - Failures of structures under cyclic long-term loadings have been assessed to be the most significant cause of huge financial losses. - Owing to purely elastic or hyperelastic initial response, state-of-the-art models for glassy polymers cannot predict cyclic deformation behavior well when - a model capable to predict real deformation behavior of glassy polymers and to simulate time-consuming and costly testings needs to be developed.