Christian Mathew, a visionary student at Virginia Tech, has propelled the field of computational science and mechanics into a new era with his development of the multiphysics phase field model.
This innovative model, developed in collaboration with the finite element-based MOOSE framework, promises to revolutionize our understanding of alloy crack initiation in both isotropic and anisotropic elastoplastic materials.
In the realms of aerospace, biomedical, and marine applications, structural components navigate the intricate challenges of mechanical loading and corrosive environments.
Matthew’s research not only comprehensively elucidates crack initiation and growth mechanisms but also sheds light on the complex processes involving local metallic dissolution, rupture of protective passive films, and the uptake of harmful species such as hydrogen during the corrosion process.
Mathew’s work transcends traditional phase field models by embracing a multiphysics approach. By concurrently considering the effects of electrochemical and mechanical factors, the model achieves a higher level of accuracy in representing real-world scenarios.
The incorporation of both isotropic and anisotropic materials, articulated through J2 plasticity and crystal plasticity, elevates the model’s predictive capabilities to unprecedented levels.
The dynamic nature of Mathew’s phase field model, driven by the reduced total free energy, establishes a thermodynamically consistent framework.
Building on recent advancements in phase field-based methods, the research extends these techniques to address the nuanced transition from corrosion pits to initial cracks.
Modifying the Allen-Cahn equation, Mathew captures the nonlinear dependence on the thermodynamic driving force of the interface kinetics.
This modification enables the modelling of Butler-Volmer kinetics, providing a more accurate representation of electrode-electrolyte interface migration. The incorporation of the film dissolution mechanism factors in mechanical effects on corrosion kinetics provides valuable insights into the pit-to-crack transition.
The model’s versatility is further underscored by its ability to describe anisotropic mechanical behaviour through the crystal plasticity model.
The study’s robustness is highlighted through compelling two- and three-dimensional examples, showcasing the computational framework’s applicability across diverse conditions.
The consistent observation of the pit-to-crack transition emphasizes the model’s proficiency in predicting crack initiation and growth, even when deviating from the perpendicular to the applied loading direction in materials with anisotropic mechanical behaviours.
As an introduction to this transformative model, the study tests limited parameters, paving the way for future investigations involving more complex structural geometries and loading conditions. Matthew’s team envisions exploring inhomogeneous or gradient material properties, coupled with ongoing efforts to enhance the model by incorporating diffusion-controlled interface kinetics.
Christian Mathew expresses gratitude to the National Science Foundation and the Office of Naval Research for their pivotal financial support. Special thanks are extended to Advanced Research Computing at Virginia Tech for providing indispensable computational resources and technical support.
In conclusion, Mathew’s pioneering work represents a quantum leap in our ability to predict and mitigate alloy crack initiation. This multiphysics phase field model, with its unique features and demonstrated capabilities, not only promises to reshape our approach to materials science challenges but also holds far-reaching implications for various industries.
