Research

It’s Dr.-Ing. Ethiraj for you! Here’s the presentation:
Computational Modeling of Ferromagnetics and Magnetorheological Elastomers [PDF] 

Micromagnetics or micro-magneto-elasticity  crystal-easy-directions  A Geometrically Consistent Incremental Variational Formulation for Phase Field Models in Micromagnetics. The focus of the paper was on variational-based FE solution of the coupled problem that takes into account the geometric constraint on the magnetisation in a consistent manner.

anim
Evolution of magnetic domains in Permalloy

I supervised a student, Vasantha Venkataraman for her master thesis, to use an operator split with a normalisation step which is easier to implement thus making the 3D case more accessible. The complete work with a comparative study will either be published in a journal or directly in my dissertation.

Master Thesis: “Theory and Numerical Aspects of Constitutive Modeling in Finite Deformation Magnetomechanics”    mre-thesis My master thesis on finite deformation modelling of magnetorheological elastomers dealt with constructing free-energy (-enthalpy) functions in terms of tensorial invariants. The particular form of the functions were motivated by experimental results and other existing phenomenological models. Three different free energy enthalpies were reported in the work. [Download PDF here]

Internship: “Implementation of a Parameter Identification Algorithm for Finite Magnetostriction Models” (Advisors: B. Kiefer and Prof. C. Miehe)

intern-paramid

My internship report deals with parameter identification that uses gradient-based optimisation algorithms of sequential quadratic programming using active set strategies for inequality constraints. The objective was to have a method that enables us to find the best set of material parameters by comparing output from simulations with experiment. It is a minor extension of already existing work by C. Miehe, A. Rieger and G. Scheday. [Download PDF here]

Finite Deformation Modelling of Magnetorheological Elastomers (Elasticity and Viscoelasticity): Not yet declassified…

Useful, but hard to find papers:
Some papers that I found hard to find (perhaps there’s someone else out there looking for these papers)
1. Piezomagnetism in the Antiferromagnetic Fluorides of Cobalt and Manganese, Borovik-Romanov [Download PDF: borovik-romanov60]
2. Magnetic Symmetry of Crystals, Tavger and Zaitsev [Download PDF: tavger+zaitsev56]
3.  The Problem of Piezomagnetism, Dzialoshinskii (or Dzyaloshinsky) [Download PDF: dzialoshinskii58]
4. A Thermodynamic Theory of “Weak” Ferromagnetism of Antiferromagnetics, Dzialoshinskii (or Dzyaloshinsky) [Download PDF: pic_2014-08-06_133605]

Leave a Reply

Your email address will not be published. Required fields are marked *