Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Session Chair: Sven Klinkel, RWTH Aachen Universtity Session Chair: Alexander Düster, Hamburg University of Technology
Location:Auditorium Wolfsburg
Presentations
A total Lagrangian position-pressure mixed finite element formulation for thermo-mechanical phase change analysis of incompressible materials
Péricles Rafael Pavão Carvalho, Rodolfo André Kuche Sanches
University of São Paulo, Brazil
We present a coupled thermo-mechanical formulation for solving non-isothermal phase change problems, using a total Lagrangian description. For the mechanical problem, a mixed position-pressure Finite Element formulation is proposed to solve incompressible materials - both fluids and solids - in a unified framework. To overcome the numerical instabilities of the incompressibility circunventing Ladyzhenskaya-Babuška-Brezzi conditions, an adapted pressure stabilizing Petrov-Galerkin technique is applied. We consider the Newtonian constitutive model for fluids, a hyperelastic constitutive model for solids, and a mix of these models for the mushy phase. While fluid problems are most commonly expressed in terms of velocities, the use of velocity-based formulations on solid materials is generally limited to hypoelastic-derived constitutive models. Therefore, to account for hyperelastic solids while still applying a unified treatment of unknown variables, the fluid problem is also equationed in terms of positions. A partitioned method for thermo-mechanical coupling is employed, using a temperature-based Finite Element Method for solving the heat transfer problem, and the enthalpy method for phase change implementation. Finally, representative numerical examples are simulated to show the potentialities of the proposed formulation.
