Thermodynamic model for strain-induced crystallization in rubber - Eccomas

Natural rubber (NR) is known to crystallize under strain (SIC) so that NR samples subjected to loading-unloading cycles exhibit hysteresis. A brief review of the numerous experiments conducted on this material is given. Detailed information on the microstructure is therefore available, particularly simultaneous measurements of stress versus elongation and

crystallinity versus elongation. Introducing an internal variable associated to crystallinity, a solution to the evolution of this variable can be found, that is thermodynamically consistent. This variable enable us to obtain good laws for both stress-strain and crystallinity-strain curves. This model is assessed by uniaxial tensil tests under cyclic loadings.