ITLApplied  Computational Mathematics Division
ACMD Seminar Series
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On the Use of Fully Three Dimensional Multifield Mixed Finite Element Scheme in Multiscale Structural and Building Energy Efficiency Simulations

Dubravka Mijuca
Faculty of Mathematics, Department of Mechanics, University of Belgrade, Serbia

Thursday, June 28, 2007 15:00-16:00,
Building 101, Lecture Room A
Thursday, June 28, 2007 13:00-14:00,
Room 4550

Abstract: The multiscale robust original fully three dimensional primal mixed finite element approach in thermo-mechanical solid mechanics, which can bridge simulations on micro, meso and nano levels, will be presented in detail. The first goal was to develop a numerical simulation procedure that enables the thermo-mechanical analysis of the megastructure, from macro to microscale and atomistic levels, in one simulation framework. The second goal was to develop a reliable procedure that will enable the highest level of interoperability between structural and energy efficiency in the civil construction sector. Contemporary hardware and mathematical resources to handle large scale computing open doors for richer FE theories in which reliability is not compromised, even if the model problem to be analyzed requires consideration through geometrical scales from continuum to micro to nanomechanics. In addition, integral energy efficiency can be approached by very fine thermal modeling of small details, for example, thermal bridges in wall systems that include metal bolts. The reliability of the present approach relies on the robustness of the underlying primal mixed finite element scheme, which is insensitive to extreme distortion of hexahedral finite elements. The essential contribution of the present approach is to enforce the continuity of the dual variables, stress and heat flux, everywhere on the body and consequently on the surfaces of material discontinuity. This enables reliability, as well as smooth behavior of the primal variable (displacement and temperature) in the vicinity of singularity. The application of this technique in industrial problems that require multiscale simulation includes composite sandwiched plates with foam in its core, fiberoptic sensors embedded in composite materials, and microcoating technology. The final example is a simulation of the building envelope, as an integral part of energy efficiency assessment in the residential sector by contemporary simulation tools, such as EnergyPlus (

Speaker Bio: Dubravka Mijuca is a Professor in the Department of Mechanics at Faculty of Mathematics University of Belgrade, Serbia, where she received her MSc and PhD in Computational Mechanics. Her research interests include the novel and reliable fully three-dimensional multifield mixed finite element procedures in thermomechanics for the isotropic, anisotropic and composite bodies with material interfaces, which can be bridged with simulations on micro and nano geometrical levels, without spurious oscillations of the results. The main goal in her research is reliable mechanical and thermal stress calculation on material interfaces, such as, interface between plies in composite, and over the interface of the coating, as well nonphysical interfaces, such as interface between boundary of the macro and nano simulation levels. In addition, her research interest, beside structural efficiency is also in simulation of the energy efficiency of buildings, influence of thermal characteristic of building envelope throughout the geometrical scales on integral energy efficiency of buildings, and interoperability of these two simulations. She is a vice president of Serbian Society of Computational Mechanics, member of general council of Serbian Society of Mechanics, member of NAFEMS and IUTAM. Professor Mijuca's publications have appeared in the journals Computational Mechanics, Computer Assisted Mechanics and Engineering Sciences, Facta Mechanics and Thermal Science. She has published a monograph entitled On Primal-Mixed formulation in Elasticity and Thermoelasticity.

Contact: G. B. McFadden

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