By a News Reporter-Staff News Editor at Journal of Technology -- Investigators publish new report on Solids Research. According to news reporting originating from Essen, Germany, by VerticalNews correspondents, research stated, "This paper introduces an electro-mechanically coupled phase field model for ferroelectric domain evolution based on an invariant formulation for transversely isotropic piezoelectric material behavior. The thermodynamic framework rests upon Gurtin's notion of a micro-force system in conjunction with an associated micro-force balance."
Our news editors obtained a quote from the research from the University of Duisburg-Essen, "This leads to a formulation of the second law, from which a generalized Ginzburg-Landau evolution equation is derived. The invariant formulation of the thermodynamic potential provides a consistent way to obtain the order parameter dependent elastic stiffness, piezoelectric, and dielectric tensor. The model is reduced to 2d and implemented into a finite element framework. The material constants used in the simulations are adapted to meet the thermodynamic condition of a vanishing micro-force. It is found that the thermodynamic potential taken from the literature has to be extended in order to avoid a loss of positive definiteness of the stiffness and the dielectric tensor. The small-signal response is investigated in the presence and in the absence of the additional regularizing terms in the potential. The simulations show the pathological behavior of the model in case these terms are not taken into account."
According to the news editors, the research concluded: "The paper closes with microstructure simulations concerning a ferroelectric nanodot subjected to an electric field, a cracked single crystal, and a ferroelectric bi-crystal."
For more information on this research see: An invariant formulation for phase field models in ferroelectrics. International Journal of Solids and Structures, 2014;51(11-12):2144-2156. International Journal of Solids and Structures can be contacted at: Pergamon-Elsevier Science Ltd, The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, England. (Elsevier - www.elsevier.com; International Journal of Solids and Structures - www.elsevier.com/wps/product/cws_home/297)
The news editors report that additional information may be obtained by contacting D. Schrade, University of Duisburg Essen, Inst Mech, D-45141 Essen, Germany. Additional authors for this research include R. Muller, D. Gross, M.A. Keip, H. Thai and J. Schroder.
Keywords for this news article include: Essen, Europe, Germany, Solids Research
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