PhD positions - AALBORG University
At the Faculties of Engineering, Science and Medicine, Department of Mechanical Engineering a position as
Ph.D. fellow (position no. 562/06-15-29137) is open for appointment from 1.8.2009.
Job description:
Modelling of the Non-linear Response of Polymer Foam Cored Sandwich Structures subjected to Combined Mechanical and Thermal Loadings
The PhD stipend is available within the general study programme “Mechanical Engineering”.
The stipend is affiliated with the research project “Thermal degradation effects in polymeric foam cored sandwich structures” financed by the Danish Research Council for Technology and Production Sciences (FTP).
The project will be carried out in close collaboration with the University of Southampton, School of Engineering Sciences, UK. The project includes a placement of the PhD student of up to 9 months of the 3 year project period in Southampton with the School of Engineering Sciences, UK. The purpose is to participate in the UK part of the project where the focus will be on the development of advanced experimental facilities for full scale testing of composite and sandwich materials and structures.
The project also involves the industrial partners DIAB AB, Sweden (DIAB is one of the worlds largest manufacturers of high performance foam core materials based on PVC and PET), LM Glasfiber A/S, Denmark (LM is the worlds largest manufacturer of wind turbine blades), and finally E.ON, UK (E.ON is one of largest power and gas companies in the world, and is operating and investing in wind turbine power plants worldwide. E.ON is currently engaged in a number of research projects concerning structural integrity and health monitoring of wind turbine blades).
Polymer foam cored sandwich structures are often subjected to aggressive service conditions which may include elevated temperatures. The mechanical properties of polymer foam cores degrade significantly with elevated temperatures, and significant changes in the properties may occur well within the operating range of temperatures. When mechanical and thermal loads act simultaneously, nonlinear interaction effects may occur and subsequently lead to a complete loss of structural integrity. Recent theoretical/numerical models have been used to investigate and quantify these thermal degradation effects, which are important for e.g. composite sandwich wind turbine blades, boat/ship structures as well as for applications in the transportation and aerospace sectors.
The purpose of overall FTP project is to provide a detailed experimental validation of the available models, as well as to further develop and refine the modelling capabilities with a special focus on their adaptation for engineering design purposes. The experimental results will be used to inform the models, and thereby accurately define the load/temperature limits that mark the degradation on-set. The experimental work will also provide a detailed characterisation of polymer foam core materials to determine the effect of thermal degradation on the sandwich structure performance.
In particular, this PhD project will include the thermo-mechanical modelling of general sandwich plate and shell structures. The sandwich plate/shell modelling will include buckling and post-buckling, interactions between thermal and mechanical loads and also the vibration response.
The research will encompass the following:
- Development of high-order plate and shell formulations which include the core transverse flexibility, geometric nonlinearity and temperature dependent material properties (core and face sheets).
- Correlation and comparison between test data and predictions of the developed high-order models. Based on this, improvements of the developed models will be proposed and implemented.
- Conduction of extensive numerical and parametric studies of the load response of foam sandwich plate/shell structures with temperature dependent material properties. Focus will be placed on the study of thermal buckling and post-buckling, as well as the general nonlinear response characteristics when thermal and mechanical loads are acting simultaneously.
- Development of nonlinear finite element analysis procedures in general purpose finite element analysis (FEA) packages.
- Comparison of experimental sandwich panel test results obtained in parallel with PhD predictions of the non-linear FEA modelling. This includes studies of the influence of boundary conditions and thermal gradients across the sandwich panel/plate thickness (combined mechanical and thermal loading) will be conducted.
- Design studies supported and validated by experimental results.
Applicants for the PhD position should hold a Masters Degree in preferably Mechanical or Civil Engineering with a strong background in mechanics and materials engineering. A good command of oral and written English is also required.
Qualification requirements:
PhD stipends are allocated to individuals who hold a Masters degree. PhD stipends are normally for a period of 3 years. It is a prerequisite for allocation of the stipend that the candidate will be enrolled as a PhD student at the Doctoral School of the Faculties of Engineering, Science and Medicine, in accordance with the regulations of Ministerial Order No. 18 of January 14, 2008 on the PhD Programme at the Universities. According to the Ministerial Order, the progress of the PhD student shall be assessed every six months. It is a prerequisite for continuation of salary payment that the previous progress is approved at the time of the evaluation.
The qualifications of the applicant will be assessed by an assessment committee. On the basis of the recommendation of the assessment committee, the Dean of the Faculties of Engineering, Science and Medicine will make a decision for allocating the stipend.
Appointment and salary acc. to the Ministry of Finance Circular of January 11, 2006 on the Collective Agreement for Academics in Denmark, Appendix 5, regarding PhD fellows, and with the Ministry of Finance Circular of June 13, 2007 on the employment structure at Danish Universities.
For further information about stipends and salary contact Ms. Tine Lützhøft, The Faculties of Engineering, Science and Medicine, email:
tl@adm.aau.dk, phone: +45 9940 7380.
The PhD application form can be downloaded from the following address:
http://www.phd.ins.aau.dk/get-a-phd/3591832
The faculty has a research school, The Doctoral School of Engineering, Science and Medicine:
http://www.phd.ins.aau.dk and a Network for all PhD students:
http://pau.aau.dk
You may obtain further information from Professor Ole Thybo Thomsen, phone: +45 9940 9319, email:
ott@me.aau.dk concerning the technical aspects of the stipend.
Application marked the PhD stipend No. 562/06-15-29137, should include in four copies: the PhD application form, the Masters diploma including grades, publications, Curriculum Vitae and any other material, as well as a list of submitted material. Due to legal constraints electronic applications will not be accepted.
The application must arrive at Aalborg University with the morning post by the 2.6.2009.
Application is to be forwarded to :
Aalborg Universitet
De Ingeniør-, Natur- og Sundhedsvidenskabelige Fakulteter
Niels Jernes Vej 10
DK-9220 Aalborg Øst