Department of Mechanics: Seminar: Abstract Tuma 2018

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Finite strain phase-field model for martensitic transformation in shape memory alloys

Karel Tůma, Mathematical Institute, Faculty of Mathematics and Physics, Charles University.

Department meeting room (B-366), Faculty of Civil Engineering, Czech Technical University in Prague

Thursday, 6 December 2018, 11:00-12:00

The shape memory effect or pseudoelasticity observed in shape memory alloys is associated with martensitic phase transformation. The material can exist in different phases, usually called austenite (parent phase) and martensite (product phase), the latter in different variants. During the phase transformation, interfaces are created and a part of the energy is stored in them.

We present a recently developed finite strain phase-field model for evolution of the microstructure in such material. The model is based on the minimization of the total rate-potential which describes all processes in the material, namely it consists of the free energy, comprising the elastic and interfacial energy, and the dissipation potential. The interfacial energy describes the energy of diffuse interfaces of a chosen width (parameter of the model) which is a characteristic feature of phase-field modelling.

We perform several simulations of the evolution of the microstructure in a CuAlNi shape memory alloy.