Modelling of the adhesion of bio sourced composites as a function of surface parameters of the bonded interface (pourvu)

Internship Master Project in joint supervision 

Supméca-Institut supérieur de mécanique de Paris/University of Ferrara 

 

Topic : Modelling of the adhesion of bio sourced composites as a function of surface parameters of the bonded interface. 

Public : Civil and Mechanical Engineering students. 

Time : 6 months. 

Context : Since 1956, as a public post-secondary education institution, Supméca (located in Saint-Ouen, very close to Paris) trains mechanical engineers with a strong scientific and technical culture, renowned for their competency and skills in numerical engineering, design and manufacturing. 

All research activities carried out at Supméca have been integrated into the Quartz Laboratory (no. EA 7393) since 2015. They revolve around five key themes : 

  • Tribology & Materials. 

  • Static & Dynamic Study of Mechanical Systems. 

  • Vibroacoustics & Structures. 

  • Sustainable Systems. 

  • Engineering of Mechatronic and Multi-physical Systems. 

The internship candidate will integrate the “Tribology & Materials” (TriboMat) team. 

 

Description : In the last decade, natural fiber-reinforced composite materials have gained popularity for structural applications in many engineering fields such as automotive, civil and biomedical, due to sustainable development requirements and cost-effectiveness. Despite of the massive usage, the mechanical performances of this type of materials requires further studies to be improved. Bio sourced flax/epoxy composite material will be used in this study as a structural bonded assembly. Different mechanical treatments of the composite surface will be done in order to modify the surface roughness to improve the bonding resistance. This work will involve both an experimental and a numerical part. 

The experimental part will include the following main steps : 

  • Composite fabrication (out of autoclave process, using prepreg flax/epoxy ply). 

  • Mechanical surface treatment using the sandblasting process with optimal sandblasting parameters determined during a recent PhD thesis by A. Bechikh [1] for this bio-composite. 

  • Roughness determination of treated composite surface using SurfoScan 2D and 3D measuring machine [2]. 

  • Bonding processus 

  • Tensile tests of a composite/composite bonded assembly [2]. 

All the experimental devices required for this project are available at the Quartz Laboratory. 

The numerical part of this project will mainly concern the simulations of the tensile test of composite/composite bonded assembly taking into account the surface roughness. The simulations will be carried out on Abaqus Finite Element software. 

Two modelling approaches for the surfaces roughness of the composite could be used : 

  • A realistic approach : including the 2D and 3D roughness profiles obtained by SurfoScan measuring machine, directly in the finite element model. 

  • An approximated approach : using an interface law of nonlinear spring-like type [3]. 

Ideally, the two approaches will be compared. The numerical models will be feed with experimental data to achieve the main goal of this work, which is the determination of a range of optimal values of the surface roughness parameters (e.g. Ra, Sm) which maximize the adhesion resistance of such an assembly. 

 

This work could lead to a 3-years PhD thesis in joint supervision between Supméca (Quartz Laboratory) and the University of Ferrara. 

 

Provisional planning :  

Facilities : 

  • Salary for 6 months : 600 €/month. 

  • Restaurant card with student rate (3.90 €/meal) 

  • Portable PC (with Abaqus and Matlab software) for the internship period. 

References : 

[1] Bechikh, A. (2020). Traitement de surface et caractérisation de l’adhérence dans les assemblages métal-biocomposite. PhD thesis, Université Cergy Pontoise. 

[2] Bechikh, A., Klinkova, O., Maalej, Y., Tawfiq, I., & Nasri, R. (2020). Sandblasting parameter variation effect on galvanized steel surface chemical composition, roughness and free energy. International Journal of Adhesion and Adhesives, 102653. 

[3] Raffa, M. L., Lebon, F., & Vairo, G. (2016). Normal and tangential stiffnesses of rough surfaces in contact via an imperfect interface model. International Journal of Solids and Structures, 87, 245-253. 

 

Contacts :  

Olga KLINKOVA, e-mail : olga.klinkova@isae-supmeca.fr (Supméca, Quartz Laboratory) 

Maria Letizia RAFFA, e-mail : maria-letizia.raffa@isae-supmeca.fr (Supméca, Quartz Laboratory) 

Raffaella RIZZONI, e-mail : raffaella.rizzoni@unife.it (University of Ferrara)