Calibration and Validation of a Phase-Field Model of Brittle Fracture within the Damage Mechanics Challenge

TL;DR

This paper validates a phase-field model for brittle fracture by calibrating it with experimental data and testing its predictive accuracy on a 3D printed gypsum specimen under complex loading conditions.

Contribution

It introduces a calibration procedure for a phase-field fracture model and demonstrates its effectiveness in predicting fracture behavior in a challenging experimental setup.

Findings

Model accurately predicts load-displacement behavior.

Crack paths closely match experimental observations.

Calibration method proves reliable for complex materials.

Abstract

In the context of the Damage Mechanics Challenge, we adopt a phase-field model of brittle fracture to blindly predict the behavior up to failure of a notched three-point-bending specimen loaded under mixed-mode conditions. The beam is additively manufactured using a geo-architected gypsum based on the combination of bassanite and a water-based binder. The calibration of the material parameters involved in the model is based on a set of available independent experimental tests and on a two-stage procedure. In the first stage an estimate of most of the elastic parameters is obtained, whereas the remaining parameters are optimized in the second stage so as to minimize the discrepancy between the numerical predictions and a set of experimental results on notched three-point-bending beams. The good agreement between numerical predictions and experimental results in terms of load-displacement curves and crack paths demonstrates the predictive ability of the model and the reliability of the calibration procedure.