Study of the internal friction in synthetic fiber mooring ropes of floating wind turbines

Offshore wind turbines are an important component of the energy transition underway in France and around the world. IFP Energies nouvelles studies in particular the technology of floating wind turbines, which can be deployed in relative deep sea. A critical component of the floating wind turbine is the mooring line, which is often made of a chain and a synthetic fiber rope. This PhD project will be devoted to synthetic fiber rope and particularly to the splice. Splicing is a very old technique but is still the most effective solution to end a fiber rope. However, the splice is also a structurally weak point and ropes usually break at the splice, whether in monotonous traction or fatigue. Since the splice holds by friction one has to understand the friction within the rope in order to understand, and improve, the splice behaviour. This is the core of this PhD project, The PhD student will :
-    Perform friction tests on ropes with specific devices that will have to be designed and manufactured. The friction curves will be established, according to different configurations.
-    Develop a friction model adapted to synthetic ropes, based on the models available in the literature. Implement the model in a finite element code (Abaqus) and identify it on friction tests.
-    Characterize the contact surfaces, in particular the material changes and possible damage.
-    Make splices and test them in tension, exploit the tests thanks to image analysis and simulate them by finite element, with the friction law developed. Deduce the fragility points.

The doctoral student will benefit from test benches and numerical tools available at IFPEN and IRDL. She/he will work with researchers from both institutes, specialists in offshore wind turbines, synthetic fiber ropes and their maritime applications. A rope provider will be involved in the thesis. The work will take place at IFPEN Lyon.

Keywords: mechanics of materials and structures, multi-scale simulation, friction model, friction tests, synthetic fiber rope, floating wind turbine

• Academic supervisor    Prof. Yann MARCO, IRDL, ORCID : 0000-0002-0163-7279
• Doctoral School    ED648 SPIN, ENSTA Bretagne
• IFPEN supervisor    Dr Michaël MARTINEZ
• PhD location    IFPEN, Lyon, France and IRDL / ENSTA Bretagne, Brest, France  
• Duration and start date    3 years, 3 years, starting in the fourth quarter 2024 (November 4)
• Employer    IFPEN
• Academic requirements    University Master degree in Mechanical Engineering or in Mechanics of Materials
• Language requirements    English level B2 (CECR)    
• Other requirements    Programing, finite element simulation

To apply, please send your cover letter and CV to the IFPEN supervisor indicated below.