Glass-ceramics are comprised of an inorganic, amorphous matrix with crystalline ceramic inhomogeneities.  This microstructure arises from subjecting an initial inorganic base glass to a thermal profile referred to as “ceramming” to nucleate and grown the crystalline phases.  As a result of this process, glass-ceramics exhibit interesting behaviors arising from multiple inelastic phases.  In addition to the viscoelastic matrix, the inhomogeneities can be silica polymorphs that undergo reversible solid-to-solid phase transformations exhibiting inelastic strains.  The combination of inelastic mechanisms produces a complex thermomechanical response that has led to interest in a variety of applications ranging including glass-ceramic to metal seals.  However, to-date limited efforts have been undertaken to model this material and its unique phenomenology.  The current work seeks to address this issue via the development of a continuum scale phenomenological formulation utilizing a continuum thermodynamics based internal state variable theory.  Specifically, a novel formulation combining elements viscoelastic and transformation mechanisms is pursued.  With respect to the former, a hereditary integral approach based on established theory is used to describe rate-dependent behaviors.  Established shape memory alloy theory is used as a basis to capture the behaviors of the transforming polymorphs.  Both are coupled in a fashion allowing for simultaneous evolution of both mechanisms while introducing simple descriptions for introducing the effect of complex microstructure.  The resulting model is implemented in a finite element code in a three-dimensional fashion.  A fully implicit integration scheme is derived coupling the two responses and using a viscoelastic prediction-inelastic corrector approach.  To solve the implicit equations, a line-search augmented Newton-Raphson scheme is adopted.  The verified numerical implementation of the model is then used to investigate a variety of responses and examine the behavior and performance at both the constitutive and structural levels.  First, validation exercises are examined by comparing model predictions to existing experiments like thermal cycling with varying temperature profiles.  Good agreement is noted between the model and experimental results.  Second, the performance of the model in structural cases is examined by considering a simple glass-ceramic to metal seal example and the performance of the new model versus existing benchmarks is examined.  The impact of different mechanisms and model features is then examined and discussed.  

 

Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA0003525.


Glass-Ceramic Material Modeling: Theory, Implementation, and Application

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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