Application deadline is January 15, 2020.

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Application deadline is over.

Applications are invited for 14 PhD positions (”Early Stage Researchers“) to be funded by the Marie Skłodowska-Curie Innovative Training Network ”Joint Training on Numerical Modelling of Highly Flexible Structures for Industrial Applications [THREAD]“ within the Horizon 2020 Programme of the European Commission.

THREAD is a consortium of 12 high-profile universities, research institutions and companies located in Austria, Belgium, Croatia, France, Germany, Norway, Slovenia and Spain, and addresses the mechanical modelling, mathematical formulations and numerical methods for highly flexible slender structures like yarns, cables, hoses or ropes that are essential parts of high performance engineering systems. The project brings mechanical engineers and mathematicians together around major challenges in industrial applications and open-source simulation software development. It establishes an innovative modelling chain starting from detailed 3D modelling and experimental work to build validated 1D nonlinear rod models, which are then brought to a system level simulation thanks to the outstanding numerical properties of the developed algorithms. This holistic approach combines advanced concepts in experimental and theoretical structural mechanics, non-smooth dynamics, computational geometry, discretisation methods and geometric numerical integration.

  • Research work on your own research project within a thematic network with the aim to obtain a doctoral degree.
  • Further education through a well-defined training programme including basic and advanced scientific training modules, secondments/internships, transferable skills training, workshops, conferences, and networking events.
  • Researchers are employed on fixed-term, full-time employment contracts. Therefore, they are entitled to pension contributions, paid holidays, and other benefits as governed by the employers. The salary is paid in accordance with the Marie Skłodowska-Curie Programme regulations for Early Stage Researchers. The net salary depends on local tax and social security regulations as well as the country correction coefficient in the host country and comprises a living, a mobility and – if applicable – a family allowance.
  • Funding for 36 months employment is available.

Applicants need to fulfil three basic eligibility criteria:

  1. You qualify as Early Stage Researcher (ESR): An ESR must, at the date of recruitment by the host, be in the first four years (full-time equivalent research experience) of their research careers and have not been awarded a doctoral degree. Full-Time Equivalent Research Experience is measured from the date when the researcher obtained the first degree entitling him/her to embark on a doctorate (either in the country in which the degree was obtained or in the country in which the researcher is recruited), even if a doctorate was never started or envisaged.
  2. You qualify with respect to the Mobility Rule: ESRs must not have resided or carried out their main activity (work, studies, etc.) in the country of the recruiting host for more than 12 months in the 3 years immediately before the recruitment date. (Compulsory national service, short stays such as holidays, and time spent as part of a procedure for obtaining refugee status under the Geneva Convention are not taken into account.)
  3. English language: ESRs must demonstrate that their ability to understand and express themselves in both written and spoken English is sufficiently high for them to derive the full benefit from the network training.

Further specific requirements are described below at Individual Projects and Requirements.

The applications have to be submitted via the THREAD Application Form (see below).

Application deadline is January 15, 2020.

In the Application Form you have to confirm that you comply with the eligibility criteria and to provide the following documents in pdf format:

  • letter of motivation including contact details of 1 to 3 scientific references
  • CV in English (preferred in Europass format, see Template)
  • copy of highest academic degree

It is possible to apply for a maximum of 5 ESR projects, please indicate your order of preference in the Application Form. In your letter of motivation explain why you have selected the project(s).

The Project Coordinator receives, collects and forwards the applications to the respective supervisors. They select three candidates to be discussed in the Supervisory Board. The selected candidates will be invited to interviews with the beneficiaries interested (online or face to face) where the final choice will be made following the local procedures.

THREAD’s recruitment strategy aims at an appropriate gender balance and therefore women are strongly encouraged to apply.

For more information please also see the Information package for Marie Skłodowska-Curie fellows.

Please note: To meet the eligibility criteria as outlined above is mandatory. All requirements will be evaluated prior to appointment.

Objectives

The ESR develops numerically stable and structure preserving coarse‐grid discretisations in space and time for Cosserat rod models including internal and external constraints resulting, e.g. from inextensibility or contact conditions.

Expected Results

The proposed methods are analysed theoretically following the variational integration framework and implemented practically in an open‐source, error‐controlled variable step size Lie group integrator for flexible mechanical systems. This solver will allow to combine advanced modelling features like nonlinearities, complex constitutive laws or contact conditions with a reliable, robust and efficient system simulation.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mathematics, Computer Science, Computational physics, Computational engineering or related fields is preferred (all backgrounds are welcome to apply).
  • Experience in numerical software development is highly desirable.
  • Experience in mathematical modelling with differential equations is desirable.
  • High standard of spoken and written English.
Host
Primary Supervisor
Martin Arnold (Institute of Mathematics)
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Objectives

Development and analysis of local frame methods for the simulation of textile manufacturing processes: modelling of continuous 1D yarn and cable structures with geometric nonlinearities, representation of contact conditions based on the non-smooth contact dynamics approach, numerical discretisation methods in space and time using Lie group interpolation and efficient solution algorithms for non-smooth flexible multibody systems on Lie groups.

Expected Results

ESR2 will establish a finite element formulation for cables and rods with contact based on the local frame approach. Besides theoretical investigations, the method will be implemented in the finite element simulation code Oofelie jointly developed by ULG and GDTECH and will be applied to model the textile braiding process. The simulation should allow to predict the influence of some key parameters of the braiding machine on the final product layout. ESR2 will also benefit from close interactions with ESR3 for the development of the modelling and simulation tool.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mechanical Engineering, Aerospace Engineering, Computational Engineering, Computational Physics or related fields is preferred (all backgrounds are welcome to apply).
  • Experience in numerical software development is highly desirable.
  • Experience in modelling methods in mechanics and dynamics is desirable.
  • High standard of spoken and written English.
Host
Primary Supervisor
Olivier Brüls (Department of Aerospace and Mechanical Engineering)
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Objectives

The ESR will develop models of wire bundles based on non-smooth contact dynamics with applications to wiring harnesses which are compound, multi-wired rod-like structures. The simulation tool will combine an open-source advanced contact solver developed by INRIA in a project on hair simulation with an open-source rod formulation to be developed by ESR3. The ESR will conduct a comparison of these two approaches in terms of robustness and efficiency. The final aim of ESR3 is to develop a simulation code for mesoscopic structure models to perform virtual experiments able to reproduce and predict the outcome of the experiments performed by ESR11 in hardware.

Expected Results

Virtual experiments with mesoscopic models developed by ESR3 yield a powerful tool to analyse and interpret the outcome of the experiments performed by ESR11, provide an independent approach, complementary to the one developed by ESR6, to study harness-like structures, and thus enables a mutual validation of these methods.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mechanical Engineering, Aerospace Engineering, Computational Engineering, Computational Physics or related fields is preferred (all backgrounds are welcome to apply).
  • Experience in numerical software development is highly desirable.
  • Experience in modelling methods in mechanics and dynamics is desirable.
  • High standard of spoken and written English.
Host
Primary Supervisor
Olivier Brüls (Department of Aerospace and Mechanical Engineering)
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Objectives

Incorporate available data information in models for slender structures (e.g. oil reisers). Usage: 1) validation of existing physical models; 2) new, fully data driven models; 3) models being partly data driven, partly obtained by Cosserat theory; 4) studies of structural fatigue, validation by measurements, analysis of material properties and physical characteristics.

Expected Results

Improved models for cable simulation (discretised and implemented in a code). The designed models will be analysed using techniques based on shape analysis on Lie groups where the motion of the cables is considered as a space-time dependent curve on the Lie group SE(3) (in collaboration with ESR5). The deformation and motion of the cable can be seen as the geodesic curve in an infinite dimensional manifold. The features of this deformation can be determined by optimal control problems or alternatively, using machine learning and deep neural networks. ESR4 benefits from data generated in virtual experiments (ESR3, ESR6) and real experiments (ESR11).

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mathematics, Computer Science, Computational physics, Computational engineering or related fields is preferred (all backgrounds are welcome to apply).
  • The admission to PhD education at NTNU requires an average grade of A or B within a scale of A-E for passing grades (A best) for the last two years of the MSc, and C or higher for the BSc.
  • Applicants must also satisfy the requirement for entering the PhD programme at NTNU; please see https://www.ntnu.edu/ie/research/phd for more information.
  • Experience in programming numerical methods is highly desirable, in particular knowledge and experience with programming languages such as Matlab or Python.
  • Experience in mathematical modelling with differential equations is desirable.
  • Applicants who do not master a Scandinavian language must document a thorough knowledge of English (equivalent to a TOEFL score of 600 or more).
  • The appointment is to be made in accordance with the regulations in force concerning State Employees and Civil Servants and national guidelines for appointment as PhD, post doctor and research assistant.
Primary Supervisor
Elena Celledoni (Department of Mathematical Sciences)
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Objectives

Study implementation issues for Lie group integrators and invariant preserving integrators. Results will include: 1) Variable step size Lie group integrators with error control; 2) Invariant preserving schemes for mechanical systems evolving on Riemannian manifolds; 3) Model reduction applied to large dynamical systems on Lie groups and manifolds.

Expected Results

New software generation for Lie group integration to be used for concrete applications from THREAD. For Lie group integrators with stepwise updated local coordinates standard error control from integrators on linear spaces can be applied. There is no such direct reference to coordinate charts for composition based Lie group integrators making them more tricky to work with (order conditions for non-commutative spaces). As for integral preserving schemes the use of retractions will be essential, in particular efficient maps based on geodesics. For large dynamical systems on manifolds the methodology for reducing the dimension will follow ideas from shape analysis, collaboration with ESR4 is natural.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mathematics, Computer Science, Computational physics, Computational engineering or related fields is preferred (all backgrounds are welcome to apply).
  • The admission to PhD education at NTNU requires an average grade of A or B within a scale of A-E for passing grades (A best) for the last two years of the MSc, and C or higher for the BSc.
  • Applicants must also satisfy the requirement for entering the PhD programme at NTNU; please see https://www.ntnu.edu/ie/research/phd for more information.
  • Experience in programming numerical methods is highly desirable, in particular knowledge and experience with programming languages such as Matlab or Python.
  • Experience in mathematical modelling with differential equations is desirable.
  • Applicants who do not master a Scandinavian language must document a thorough knowledge of English (equivalent to a TOEFL score of 600 or more).
  • The appointment is to be made in accordance with the regulations in force concerning State Employees and Civil Servants and national guidelines for appointment as PhD, post doctor and research assistant.
Primary Supervisor
Brynjulf Owren (Department of Mathematical Sciences)
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Objectives

Taking into account frictional contact interactions between wires by means of a dedicated finite element simulation approach, the ESR will characterise the complex constitutive behaviour of multi-wire cables.

Expected Results

The study is aimed at determining nonlinear relationships between resultant quantities which are governed by internal mechanisms within cables. The nonlinear couplings between loadings in different directions due to internal frictional interactions will be explored and enlightened. Hysteretic effects within multi-wire cables are expected to be characterised by this approach. The characterisation of these dissipative effects is of first importance for the prediction of damage occurrence in cables used in various industrial applications.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Computational Mechanics, Mechanical Engineering or related fields is preferred.
  • Experience in solid mechanics, mechanical modelling and finite element analysis is desirable.
  • Experience in numerical simulation and software development is desirable.
  • High standard of spoken and written English.
Host
Centrale Supélec, Paris (France)
Primary Supervisor
Damien Durville (MSSMat Laboratory)
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Objectives

Development of a general flexible multibody formulation for physically meaningful automatic modelling and real-time simulation of reeving systems as a set of rigid bodies connected with wire ropes or belts using sheaves or reels. The dynamics of many industrial machines (e.g. cranes, printers, elevators, deployable structures, … ) fit to this definition.

Expected Results

A computational code for the automatic generation and numerical solution of the equations of motion of reeving systems based on a systematic and well-structured set of input data. The model must show the overall dynamic of the system for common operation condition of industrial machines based on the knowledge of commonly used parameters associated to the wire ropes, sheaves, reels and drive motors.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mechanical Engnieering, Aerospace Engineering, Computational Engineering or related fields is preferred (all backgrounds are welcome to apply).
  • Knowledge of multibody system dynamics is desirable.
  • Knowledge of the finite element method is desirable.
  • Experience in numerical software development is desirable.
  • Programing with Matlab, C++ and Python is desirable.
  • High standard of spoken and written English.
  • Working language will be English, however, some knowledge of Spanish is very convenient.
Host
Primary Supervisor
José Escalona (Department of Mechanical and Manufacturing Engineering)
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Objectives

The ESR develops efficient models for simulating mass points transported along ropes and cables taking into account the 3D contact with sheave batteries. The arbitrary Lagrangian-Eulerian (ALE) formulation shall be embedded into finite element formulations. Efficient computer implementations shall be realized in open source codes using Python and/or C++. The section properties of ropes and cables will be developed in cooperation with ESRs of work package 1.

Expected Results

The stationary treatment of the system with periodic excitation by the mass points shall lead to a better understanding of resonances and instabilities in transportation systems with highly flexible structures.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mechanical Engineering, Mechatronics, Mathematics, Computational engineering, Computer Science or related fields is preferred.
  • Experience in mechanical modelling, multibody dynamics or finite elements is highly desirable.
  • Experience in numerical simulation and software development is desirable.
  • High standard of spoken and written English.
Host
Primary Supervisor
Johannes Gerstmayr (Department of Mechatronics)
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Objectives

The ESR will work on mechanical analysis of satellite aerials during the rocket-launch phase, when they are exposed to extreme inertial loading and high-frequency vibration and impacts in a compact confinement within a rocket. The design requirement is that the satellite should occupy as little space within the rocket as possible, yet still be able to allow the aerials to deploy without permanent deformation or damage upon satellite ejection from the rocket into the orbit. The simulation will be performed using 1D Cosserat continuum (geometrically exact beam theory) and non-linear finite-element analysis in both statics and dynamics within which various interpolation options will be investigated for accuracy and robustness. In addition, a number of time-stepping schemes will be devised, which shall respect geometry of the problem configuration space and preserve mechanical constants of motion. The work will be supported by an industrial partner in space technologies.

Expected Results

The project is expected to result in higher-order spatial interpolation of displacements and rotations parametrised to provide objective solutions on the non-linear problem manifold. Conservative time-integration techniques devised on different non-linear manifolds will be assessed and generalised to account for unilateral constraints. A test rig will be designed and employed to provide experimental validation.

Project specific requirements (additional to the Eligibility Criteria)
  • Master Degree in Engineering, Mathematics, Physics or related fields.
  • Minimum average grade on the previous study level of 3.0 on the national scale between 1 (lowest) and 5 (highest), equivalent to 67.5% (transcript of records required).
  • Experience in finite-element design and analysis is highly desirable.
  • Experience in numerical simulation in dynamics and software development is desirable.
  • High standard of spoken and written English.
Primary Supervisor
Gordan Jelenić (Chair of Engineering Mechanics)
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Objectives

The ESR faces the challenging research question of the development of a variational formulation of the interaction of beam with a layered cross-section structure with a surrounding that strongly limits its deformation. Based on multi-material cross-section models, the structure is to be optimised with respect to its mechanical properties. A structure preserving space time discretisation guarantees a realistic simulation respecting the geometrical properties of the system.

Expected Results

The proposed methods (including adaptivity techniques) enable an efficient and structure preserving simulation of beams in cases relevant for medical device operation. Effective cross-section properties are obtained from multi-material layered models and also characterised experimentally. Application in the simulation of medical device operation leads to a deepened understanding and eventually to an optimisation of the device and the process.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc. / Dipl. (Univ.) in Mathematics, Computer Science, Computational Physics, Computational Engineering or related fields is preferred (all backgrounds are welcome to apply).
  • Experience in numerical software development is highly desirable.
  • Experience in mathematical modelling with differential equations is desirable.
  • High standard of spoken and written English.
Primary Supervisor
Sigrid Leyendecker (Chair of Applied Dynamics)
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Objectives

The ESR will develop more complex, inelastic – i.e. viscoplastic, or frequency dependent viscoelastic – constitutive models, formulated on the level of sectional quantities and thus improve the state of the art in Cosserat rod theory in industrial applications. On the basis of properly devised experiments, such models will be formulated and parameters will be identified. The interpretation of the results of experiments conducted by ESR11 in the lab at ITWM is complemented by virtual experiments, utilising the codes developed by ESRs of work package 1. The ESR will investigate the numerical aspects related to the necessary extension of the discrete Cosserat rod model and its efficient implementation in close cooperation with ESR1.

Expected Results

(a) Test rig experiments and virtual experiments will provide the basis for the development of a model based identification of effective constitutive properties of cables and hoses. (b) The resulting effective constitutive models, formulated on the level of sectional quantities, will be utilized for an enhancement of the discrete Cosserat rod model developed at ITWM. (c) The enhanced rod model will be applied for further simulation based investigations of inelastic effects appearing in practically relevant use case examples, which will be supplied by the supporting partners fleXstructures GmbH and Industrial Path Solutions Sweden AB of THREAD.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Mathematics, Theoretical or Computational Physics, Computational Engineering or related fields is preferred.
  • Experience in mathematical or physical modelling including programming skills are desirable.
  • High standard of spoken and written English.
Host
Fraunhofer ITWM, Kaiserslautern (Germany)
Primary Supervisor
Joachim Linn (Mathematics for the Digital Factory (MDF))
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Objectives

ESR will focus on nonlinear material models and their implementation in nonlinear dynamics within numerical analyses of deployable beam structures for space applications. The ESR will be trained to apply modern techniques for automatic differentiation in development of constitutive material models using symbolic approach that allows to derive accurate and efficient finite element (FE) routines including sensitivities with respect to the wide range of model parameters.

Expected Results

The results will have an impact on a wide variety of advanced space missions utilising deployable precision pointing antennas, solar sails, slender mechanisms for space debris removal and other deployable structures which must be compactly packaged for the limited size of launch vehicles and then expanded automatically in orbit. An optimal design of deployable structures is obtained from appropriate numerical models that assess the dynamic responses to vibrational loads during launch as well as their mechanical behaviour in space and the large geometric transformations.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Physics, Engineering, Computational physics, Computational engineering or related fields is preferred (all backgrounds are welcome to apply).
  • Experience in finite element method is highly desirable.
  • Experience in symbolic algebraic systems (Wolfram Mathematica, etc…) is preferred.
  • Computer programming skills are favored.
  • High standard of spoken and written English.
Primary Supervisor
Tomaž Šuštar (C3M d.o.o.)
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Objectives

The ESR will investigate the nonlinear dynamics of slender beams in large rotation nonlinear dynamics. New modelling strategies will be based on the coupling of quaternions (for rotation parametrisation) / finite elements (for discretisation) / asymptotic numerical method (for continuation) and the harmonic balance method (to get periodic solutions). Then, reduced order modelling (nonlinear normal mode concept) will be used to reduce the dynamics and obtain accurate numerical solutions. Targeted industrial applications will be nonlinear vibration absorbers, for which the stiffness of the absorber will be realised by prestressed beams. The numerical part of the work will be implemented in an open source software package based on the MANLAB solver.

Expected Results

Firstly, original and efficient numerical strategies for the nonlinear dynamics of beams in the frequency domain will be available at the end of the ESR PhD. Secondly, the special concept of nonlinear modes will be applied for the first time to those problems and tested to reduce the dynamics and also give physical insights in the phenomena

Project specific requirements (additional to the Eligibility Criteria)
  • A master of science level or an engineering degree in structural mechanics and dynamics, with a good appetite for numerical methods.
  • Programing skills with the software Matlab will be appreciated.
  • High standard of spoken and written English.
Primary Supervisor
Olivier Thomas (Laboratoire d'Ingénierie des Systèmes Physiques et Numériques)
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Objectives

The ESR will work on numerical modelling of flexible beam-like structures with a special focus on strain localization. In damaged materials, strain localisation often occurs, resulting in discontinuity of strains in structural models and local loss of uniqueness of the solution. This makes the problem challenging and special solution methods need to be designed to be capable of dealing with such phenomena. We are looking for stable, reliable and numerically efficient methods for frame-like structures.

Expected Results

A novel family of finite beam elements taking into account geometrical and material non-linearity that will be able to describe strain localisation will be proposed. Open-source software capable of efficiently solving spatial frame-like structures with strain localization is expected to be developed.

Project specific requirements (additional to the Eligibility Criteria)
  • MSc in Engineering, Mathematics, Computational Mechanics or related fields is preferred.
  • Programming skills are highly desirable, in particular experiences with Matlab or Python.
  • Experience in solid mechanics and numerical mathematics is desirable.
  • High standard of spoken and written English.
Host
Primary Supervisor
Dejan Zupan (Chair of Mechanics)
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