3 dagen geleden - Radboud Universiteit (RU) - Nijmegen
Postdoc Durability of Steel-Composite Bonded Connections in Offshore Environment
Challenge: Predict bonding strength between steel and FRP compositeNovelty: Method to predict the influence of water and temperature on bonding and composite materialBreakthrough: Long-term fatigue-resistant hybrid bonded connection for offshore and more
- Mekelweg, Delft, Zuid-Holland
- Tijdelijk contract / Tijdelijke opdracht
- Uren per week:
- 36 - 40 uur
- € 2790 - € 4402 per maand
With the increasing size of turbines and the deeper location of wind farms, the monopile foundations of offshore wind turbines increase in size, weight, and costs. Jackets can be an attractive alternative because multi-membered circular hollow section (CHS) support structures are lighter than monopiles. However, the complex welds result in reduced fatigue resistance of structural joints of circular hollow sections, thus higher costs and longer production routes for jackets than for monopiles.
In the project WrapNode-I, TU Delft will lead research with 9 industrial partners that will enable implementation of the innovative, bonded, wrapped composite joint in jackets for offshore wind turbines. We are forming a team of researchers to characterise and understand full-scale and multi-axial behaviour and the influence of the offshore environment on the durability of the joints. The team is led by Dr. Marko Pavlovic, assistant professor of Steel and Composite Structures.
The concept of an innovative bonded joining technology by wrapping composite material (a.k.a. Fibre Reinforced Polymer - FRP) around steel tubes is introduced as an alternative to traditional welded connections. Compared to complex welds, the load is transferred through a dedicated composite wrap and not through the small area of the weld. Fatigue resistance of joints is increased; thus, the tube wall thicknesses of the legs (chords) and brace members can be significantly reduced, resulting in up to 50% lighter jacket structures. In addition, the production time of the jacket is considerably shortened due to the possibility of prefabrication. Compared to monopiles, jackets manufactured with Wrapped Composite Joints offer a potential cost reduction of 25% to 50% for the supporting structures and reduction of CO2 footprint by 30% to 70%.
Your role in the project/team will be to develop characterisation and understanding of the durability of wrapped composite joins in the offshore environment through material/interface level and small-scale joints experiments and modelling. The research will rely on:
- Composite material and bonded interface testing under monotonic and cyclic loading (tensile, ILSS, CT, DCB, ENF, etc.)
- FE modelling of failure of composite material and bonded connection at mesoscale (laminate/ply) level
- Experiments/modelling of performance of composite materials under the influence of water and temperature
- Accelerated ageing of material, connection, joint specimens
The project is realised with the support of the Dutch government, GROW consortium and industrial partners: Shell, Tree Composites bv, Siemens Gamesa Renewable Energy bv, HSM bv, Smulders Projects International bv, Enersea bv, AOC Nederland bv, BÜFA composites Benelux bv and Salzgitter Mannesmann Renewables GmbH.
Visit the project's website here.
You will gain scientific experience by working in a dedicated international team of 4-5 PhD and PostDoc researchers at TU Delft. You will develop professional experience by collaborating with a team of engineers from leading industrial partners who will support the project by developing reference full-scale jacket design, design and production of materials and wrapped composite joints specimens.
Background in terms of MSc and PhD in field of (combinations possible):
- Civil/Structural Engineering (e.g. static and fatigue behaviour of steel and composite/FRP materials and bonding)
- Mechanical engineering (e.g. materials fatigue/ageing behaviour, composite materials for wind turbine blades)
- Aerospace Engineering (e.g. composites, fatigue and structural integrity)
- Planning and design of material (coupon) level experiments
- Conducting and control of material level experiments using UTMs and climate chambers
- Post-processing and analysis of monotonic and cyclic load experiments
- FEA validation and constitutive modelling of elastic and failure/fracture (composite) material behaviour
- Writing and publishing scientific papers in top journals
- Fatigue characterisation of materials/connections
- Accelerated ageing of materials/connections
- Measurement techniques using DIC, LVDTs and strain gauges
- Teaching in BSc/MSc courses related to steel/composite structures
- Supervising theses of MSc students
Duration of contract: 2 years
Salary and benefits are in accordance with the Collective Labour Agreement for Dutch Universities. The TU Delft offers a customisable compensation package, a discount on health insurance and sport memberships, and a monthly work costs contribution. Flexible work schedules can be arranged.
For international applicants we offer the Coming to Delft Service and Partner Career Advice to assist you with your relocation. An International Children's Centre offers childcare and there is an international primary school.
More information about the project can be found here.