A Finite‐Strain Phase‐Field‐Regularized Elastoplastic Damage Model for Polypropylene

ABSTRACT A rotation‐free finite‐strain phase‐field‐regularized elastoplastic damage formulation is presented for the tensile failure simulation of polypropylene (PP). The bulk response is represented by a hyperelastic–isotropic–plastic material branch formulated in a corotated intermediate configuration. Damage evolution is regularized by a cohesive‐like phase‐field formulation. The fracture‐active driving energy consists of the recoverable tensile hyperelastic energy and the stored isotropic hardening energy. A critical energy density enters the degradation calibration and controls the energetic scale for damage initiation. Irreversibility of the phase field is imposed by a variational inequality, which avoids the introduction of a history maximum field. A dog‐bone tensile specimen is used for calibration. The simulated global tensile response is compared with an experimental tensile curve, and the corresponding deformed damage state shows the abrupt localization‐induced loss of load‐carrying capacity.