Numerical modeling of time- and temperature-dependent strain-induced crystallization in rubber

Besides the numerical representation of elastic properties of elastomers, a thermo-mechanical finite element model to capture strain-induced crystallization (SIC) in elastomers under static and dynamic loading is proposed in this contribution. The reinforcement effect resulting from SIC is assumed to be strain-, time- and temperature-dependent and is modeled on the microscale. Due to the orientation of crystallized domains along the principal stretch directions, anisotropy in the material's mechanical and thermal response is captured by the proposed model. Model parameters for the SIC process and its kinetics are identified based on previously published wide-angle X-ray diffraction (WAXD) results. Numerical studies and comparisons to experimental data reveal the features of the numerical model for SIC. Within a structural example, the material model for strain-crystallizable elastomers is employed to reveal SIC in steady state rolling tires modeled within the finite element framework via a micro-meso-macro transition of the deformation and temperature field involved.