The dynamic aspect of crack propagation is a topic of deep interest in material science. The phase field fracture modeling has shown encouraging results in a dynamic framework but remains challenging in terms of the time discretization resolution. Though the implicit time integration methods are mainly used in the literature, they become limiting in nonlinear problems due to the resolution of the system of equations required. Thus, explicit time integration schemes are an alternative to avoid these massive matrix operations. This paper presents the approaches set up to adapt the coupled formulation to a full explicit time integration for both equations.
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Themes: Phase-Field Models of Fracture
A PHASE FIELD FATIGUE MODEL FOR COMPLEX LOADING SITUATIONS [Keynote]
The phase field method for fracture mechanics has drawn a lot of attention in the past decade because of its simple formulation and easy implementation. Recently, the phase field model is also applied for fatigue fracture for a uniform loading. However, there is still a lack of studies on how to consider complex loading cases in the phase field fatigue model. In this work, we extend the phase field model for non-uniform loading situations by combing it with the rainflow counting algorithm.
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NUMERICAL ASSESSMENT OF PHASE-FIELD APPROACH IN WESTERGAARD’S PROBLEM UNDER MIXED MODE LOADING
Assessment of phase-field numerical errors to classical Griffith’s theory is essential to obtain feasible solutions which do not require an excessive computational cost. This work analyses the phase-field fracture approach to Westergaard’s problem in terms of crack growth initiation under mode I and mixed mode I+II loading conditions.
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A PHASE FIELD MODEL FOR DAMAGE NUCLEATION IN GEOPOLYMER COMPOSITES
Multi-scale models have been greatly appreciated due to their ability to precisely correlate the microstructure properties with the macroscopic properties of materials. With an aim to verify the structural integrity of geopolymer composites, the microscopic cracks nucleating from the matrix and preexisting pores and the effect on their macroscopic fracture toughness are studied using a computational framework of phase field (PF) in the finite element (FE) context. To assess the effect of random distribution of voids, the representative volume element (RVE) of the composite microstructure is generated using a take and place algorithm. The elastic properties of the composites are obtained by Mori-Tanaka and Self-consistent homogenization schemes. The RVE is then used to simulate a plate under tension to study the damage initiation and propagation in geopolymer composites. The PF model investigates the crack nucleation and branching from the already-existing voids in the composites. A qualitative validation of the approach by means of crack patterns is also presented.
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