Department of Mechanics: Vacancies: UCEEB Postdocs

Announcement

The Czech Technical University in Prague - University Center for Energy Efficient Buildings (UCEEB) offers six post-doctoral positions in the field of modeling, simulation, assessment and optimization of multi-functional materials and structures.

Start date: February 2013 or later, until all positions are filled
Contract duration: 30 months (with a critical evaluation after the first year)
Deadline for applications: 31 January 2013

UCEEB in brief

Launched in October 2012, UCEEB is a newly established joint project of five faculties of the Czech Technical University in Prague. The mission of the Center is to perform high-level interdisciplinary research in the field of energy savings in buildings, utilizing a simulation- based engineering approach. The theoretical research activities will be systematically complemented with experimental validation, performed in a full-scale setting. This will provide unique data on materials, structures, and systems of intelligent control, including on their impact on the built and natural environment. Development of the Center is supported by the European Union through the Operational Program Research and Development for Innovations, project No. CZ.1.05/2.1.00/03.0091.

Project organization

The present project integrates six different topics aligned with the research activities of UCEEB. Each topic will be supervised by a mentor from the Faculty of Civil Engineering of the Czech Technical University in Prague, with long-term experience in the relevant fields of research. The project is supported by the European Union .

The mentors involved in the project include, in alphabetical order:

• Zdeněk Bittnar (full professor, Department of Mechanics, bittnar@fsv.cvut.cz)

• Milan Jirásek (full professor, Department of Mechanics, Milan.Jirasek@fsv.cvut.cz), an expert in the modeling of inelastic and time-dependent behavior of materials and structures;

• Petr Kabele (full professor, Department of Mechanics, petr.kabele@fsv.cvut.cz), his research interests include analytical and numerical modeling applied to development of high-performance cement- and lime-based composites and their structural applications, simulation of geological processes;

• Bořek Patzák (full professor, Department of Mechanics, borek.patzak@fsv.cvut.cz) with research interests in numerical methods in mechanics, particularly adaptive techniques and constitutive modeling of quasibrittle materials and in high performance computing and software development;

• Michal Šejnoha (full professor, Department of Mechanics, sejnom@fsv.cvut.cz), an expert in geometrical and constitutive modeling of ceramic, metal and polymer matrix composites with random microstructures;

• Petr Štemberk (associate professor, Department of Concrete and Masonry Structures, stemberk@fsv.cvut.cz), an expert in the design of concrete structures, experimental and numerical analysis of concrete structures and concrete technology;

• Jan Zeman (associate professor, Department of Mechanics, zemanj@cml.fsv.cvut.cz), whose expertise lies in numerical and analytical methods for random heterogeneous materials.

Research topics

Utilization of fly ash in alternative cementitious binders and concretes

Mentor: Zdeněk Bittnar (Vít Šmilauer)

Description: Fly ash is a waste material from thermally powered coal power plants. Czech republic and China have one of the highest fly ash/cement ratio. Applied research is needed to sustain increasing pressure on fly ash utilization. Coal co-combustion with organic materials is another challenging task to emerge. There is no single miracle solution for fly ash utilization but the most promising in terms of volume seems to be direct incorporation into concrete. High volume fly ash concrete has been studied for decades showing utilization potential of fly ash, ways for improvement and pitfalls. In the majority of cases, no fly ash preprocessing exists in the form of grinding or particle separation. This open new ways for research and experiments.

Experimental part needs to be supported with simulations, which quantify fly ash reactivity, depletion of capillary porosity, pozzolanic reaction, packing density, and evolution of compressive strength. Multiscale simulations provide suitable framework to address various phenomena in such multiscale concrete material. Virtual simulations should give directions of interesting areas and also to help reducing the amount of time-consuming experiments.

Specific requirements: Cement chemistry, experience with concrete, experimental background, basic programming skills (in C/C++, Python, MATLAB or similar languages), background in simulations.

Modeling of coupled cracking, creep and hygrothermal effects in construction materials

Mentor: Milan Jirásek

Description: The postdoctoral Fellow will work on a comprehensive model and simulation tool for the description of coupled thermo-hygro-mechanical effects in construction materials, in particular concrete. The model will take into account inelastic deformation processes (such as cracking or plastic yielding), viscous deformation processes, transport of moisture, and heat conduction. Particular attention will be paid to the mutual interaction between the mechanical problem and the heat and mass transfer, e.g. to the effect of temperature and humidity on creep, or to the effect of cracking on diffusivity and conductivity.

Specific requirements: Experience with nonlinear finite element analysis, good background in viscoelasticity, plasticity and continuum damage mechanics, excellent programming skills (preferably C++ or similar object-oriented languages).

Coupled multiphysics modeling of historical masonry

Mentor: Petr Kabele

Description: The research will include the development and implementation in FEM of a coupled numerical model for thermo-hygro-carbo-mechanical phenomena in masonry with lime-based mortars. The modeling will be accompanied by experiments necessary to acquire the material parameters of the individual components (mortar, stone/bricks) as well as to validate the model. Ultimately, the numerical tool should serve such goals as the prediction of overall thermal/hygral transport and accumulation properties of massive historical masonry walls or the assessment of restoration performed with new high-performance mortars.

Specific requirements: Good background in numerical methods, programming skills (C++), ability to design and perform experiments.

Development of advanced simulation tools

Mentor: Bořek Patzák

Description: Development of new algorithms which would enable efficient collaboration with architects and engineers during the conceptual design phase, based on an isogeometric approach, with attention paid to modular, object-oriented implementation, computational aspects (boundary conditions, coupling with regular FEM, multiphysics modeling, contacts), and scalable parallelization (multicore and GPU computing). Development of robust optimization tools to assist engineers in the selection of an optimal design.

Specific requirements: Good background in numerical methods and finite element method, programming skills (C/C++, Python).

Numerical modeling of hydro-thermo-mechanical response of wood structures

Mentor: Michal Šejnoha

Description: The objective is to study the transport of vapor in timber frame constructions (e.g. walls, floors or roof elements). One particular concern is the occurrence of internal condensation and the ability of the construction to dry afterwards. Coupling the transport processes with the mechanical aspect will allow us to address the impact of moisture on wood durability, strength and stiffness. The dimensional stability of the construction part can also be predicted. As it is affected by the wood structural configuration, the concept of multi-scale modeling and homogenization will also be exploited in the numerical analysis. The random nature of wood properties will also be taken into account in the simulations.

Specific requirements: Basic programming skills (in C/C++, MATLAB or similar languages)

Numerical and experimental analysis of concrete performance in irradiated environment

Mentor: Petr Štemberk

Description: The primary aim of this topic is to assess the effect of concrete composition on its long-term shielding performance when exposed to various types of radiation. Specifically, the following issues will be targeted: the effect of nanoparticles in composition, the possibility of release of nanoparticles from concrete, the activity of released nanoparticles, the possible reduction of thickness of shielding walls, the minimization of crack during construction technology. The results will be applicable for nuclear facilities and hospitals.

Specific requirements: Reasonable knowledge in the field. Basic programming skills in MATLAB.

Micromechanical modeling of thermal and acoustic insulation materials

Mentor: Jan Zeman

Description: The aim of this topic is to develop inexpensive analytical models to quantify thermal and acoustic properties of highly porous building materials utilized in energy-efficient buildings by exploring the available tools of continuum micromechanics. To this purpose, the Fellow will develop models of micro- and nano-structure of such materials, investigate the relevant structure-property relationships and utilize these results to validate the model against available data and experiments performed at UCEEB (not necessarily by the Fellow). Attention will be paid to a consistent incorporation of surface effects, so that the developed models will also be applicable to nanocomposites.

Specific requirements: Previous experience with analytical or computational homogenization theories is a strong plus. The candidate is also expected to verify the developed (analytical) models against detailed numerical simulations. Therefore, good working knowledge of numerical simulation tools and basic proficiency in computer programming is welcome.

General requirements

We are looking for candidates who

• hold a Ph.D. degree (or equivalent) in the research area related to the selected topic,
• have an ability to perform independent research with a strong emphasis on publications in refereed journals,
• possess excellent communication skills and written/verbal knowledge of the English language.

We offer

• the possibility to work in a newly established dynamic and ambitious research center with the state-of-the art equipment,
• a 30 month contract with a critical evaluation after the first year,
• a gross salary of 58,000 CZK per month (approximately 2,300 Euro or 2,900 USD),
• a partial coverage of the mandatory social and medical insurance by the employer (the employee has to contribute 6.5% of the gross salary to pension insurance, 4.5% to health insurance and, according to the currently valid legislation, approximately 16.5% is deduced as income tax),
• the coverage of travel expenses of up to 55,000 CZK per year,
• the coverage of operating of costs up to 40,000 CZK per year.

Application

For more information, please contact the mentor using the e-mail address specified above.

Interested candidates are invited to send their applications directly to the relevant mentor no later than 31 January 2013. The application must contain

• a Curriculum Vitae (one page),
• a motivation letter (two pages), stating personal goals and research interests,
• a detailed list of publications,
• two letters of recommendation sent by the referees directly to the mentor (with detailed contact information: email, telephone number and address), one of them written by the previous supervisor,
• a certificate of proficiency in English (CAE, TOEFL or equivalent) or an electronic copy of the candidate’s Ph.D. thesis written in English.

Both national and international applications to this advertisement are appreciated. Review of applications will begin immediately and continue until all the positions are filled. Promising candidates will be contacted by e-mail, and will be invited for an interview at the Czech Technical University in Prague (with reasonable travel costs covered by the project).