Computational modeling of fracture in polymer nano‐composites undergoing large deformations via the graded‐interphase‐enhanced phase‐field fracture approach

Abstract

The phenomenon of fracture in polymer composites, polymer nano‐composites in particular, entails a multitude of intricate mechanisms including branching and merging of several cracks along with particle debonding and subsequent plastic void growth. This work involves an extension of the standard phase‐field fracture approach by means of the graded interphase concept in order to facilitate the modeling of a wide‐spectrum of fracture responses, which can be observed in experimental studies concerning the fracture behavior of polymer nano‐composites. Herein, motivated by the microstructure morphology of polymer nano‐composites, a continuous grading of the elastic and fracture properties is considered within a finite thickness interphase region around the filler particles. Appropriate tuning of the graded‐interphase model parameters enables to capture a variety of fracture responses, including cohesive failure between the filler particle and the matrix, as demonstrated via the presented numerical examples, which focus on polymer nano‐composites undergoing large deformations prior to fracture.