Phase-field analysis for brittle fracture in ferroelectric materials with flexoelectric effect

TL;DR

This paper develops an extended phase-field model to analyze brittle fracture in ferroelectric materials, incorporating flexoelectric effects, revealing how initial polarization influences crack propagation and providing insights into electromechanical failure.

Contribution

Introduces a novel phase-field model that includes flexoelectric effects and multiple order parameters to study fracture and domain evolution in ferroelectric materials.

Findings

Flexoelectric effect influences crack path and extension rate.

Initial polarization direction affects fracture behavior.

Model can be applied to complex ferroelectric structures.

Abstract

Understanding the nature of brittle failure in ferroelectric materials is essential, but difficult due to the complex interaction between mechanical and electrical concentrated fields near the crack tip. In this work, an extended phase-field model incorporating multiple order parameters is constructed to analyze the coupled evolution of fracture and domain behavior in ferroelectric materials. The strain gradient is incorporated into the governing equations to evaluate the impact of the flexoelectric effect during the crack propagation process. Our advanced phase-field model demonstrated that, with the consideration of the flexoelectric effect, both the crack extension rate and crack path are related to the initial polarization direction. This phenomenon is associated with the eigenstrain induced by the flexoelectric effect. This study provides in-depth insight into the fracture behavior of ferroelectric materials. The developed model framework can also be employed to investigate electromechanical coupling failures in more complex ferroelectric structures.