A phase-field thermomechanical framework for modeling failure and crack evolution in glass panes under fire

Abstract

This paper presents a novel phase-field thermomechanical modeling framework for predicting complicated behaviors of thermal cracking in glass panes under fire. The main idea is to incorporate the proposed mathematical model, which calculates the exact deformation of the mesh elements, into the variational phase-field model to simulate the thermal fracture behavior in glass panes in an effective manner. The developed model improves upon previous attempts to predict thermal cracking in the following ways: (1) in a major departure from the classical phase-field simulation of thermomechanical fracture, crack evolution can be predicted using only temperature distributions; the phase-field formulations are kept fixed to overcome mesh dependency and convergency; (2) the new modeling framework directly transforms temperature variations into thermal strains (rate of loading) using fewer mesh elements and a larger time step, thus substantially reducing the computational effort; and (3) the proposed model can simultaneously predict multiple cracks distributed in any arbitrary space in the glass panes more realistically than the previous numerical models, regardless of glass pane type and size, fixation method, and thermal loading variation. The proposed coupling model is validated through comparisons against experimental observations and ANSYS simulations. Moreover, the validated model is used to examine for the first time the effect of real engineering influential conditions, namely the heating rate, glass pane size ratio under non-uniform thermal loading, and glass pane fixation with a frame on three sides, on thermal cracking behavior.