Evaluation of the Effective Fracture Toughness in a Phase-Field Model via Image Segmentation Method

• Grant number: 25/15427-7
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2025
• End date: November 30, 2026
• Field of knowledge: Engineering - Mechanical Engineering - Mechanics of Solids
• Principal Investigator: Marco Lucio Bittencourt
• Grantee: Arthur Feitosa Alves Toledo
• Host Institution: Faculdade de Engenharia Mecânica (FEM). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 23/03047-0 - Structural integrity analysis of anisotropic materials using phase field models, AP.R

Abstract

This undergraduate research project aims to calculate the effective fracture toughness in an anisotropic phase-field model. In general, phase-field models require the input of the energy needed to initiate fracture in brittle materials. One way to verify the validity of the model is to check whether the fracture toughness obtained from numerical simulations is close to the prescribed input value.To achieve this, it is necessary to calculate both the variation in fracture-related energy and the change in crack length. However, due to the diffuse nature of crack representation and the possibility of multiple cracks propagating along nonlinear paths, accurately determining the actual crack length becomes challenging.The phase-field model was implemented in C++ and computes the variation in fracture energy. Through an image segmentation process, the diffuse crack region can be reduced to a single-pixel-width line. Then, the crack length is measured based on this skeletonized version of the image.To effectively validate both the image segmentation method and the phase-field fracture model, a series of analyses involving complex crack propagation paths will be carried out. This study aims to clarify the convergence of the effective Griffith fracture energy through precise crack length measurements.