On Monday 26 June 2023 at 2.00 p.m, Ms Gamze ÇAKIR(KABAKCI) will be supporting his thesis work at ISAE-Supméca entitled : " Toughening Mechanism Analysis of Recycled Rubber Based Composites Reinforced with Glass Bubbles and Alumina Fibers" and directed by Monsieur Emin BAYRAKTAR

Abstract :

In this thesis, low cost devulcanized recycled rubber-based composites designed with micro glass bubble (GB) which provide excellent weight reduction with high strength-to-density ratio and alumina fiber reinforcements are investigated in detail by means of toughening mechanisms, mechanical and physical properties as well as microstructural and fracture surface analysis. Mechanical properties of the composites are extensively investigated to obtain the data for basic material parameters. After determination of the inclusions in matrix by volume and weight percent, the effort is concentrated on the effects of recycled rubbers and the reinforcements on toughening mechanisms and various reinforcements including glass bubble microspheres and alumina fibers are employed to provide multifunctionality to the composites. After the general characterizations of the composites, certain additional tests and measurements are carried out. The test results are reproduced numerically by finite element analysis (FEA) using ABAQUS/Standard. Simulations are run for different randomization of the inclusions for different sized macrostructures to verify the reproducibility of the numerical results. Furthermore, representative volume elements (RVEs) containing randomly distributed spherical inclusions are considered for homogenization. Periodic boundary conditions (PBCs) are applied to the RVE to replace the heterogeneous composite with an equivalent homogeneous material. To describe the stress-strain response of the random heterogeneous composite, the average stress and strain tensors over integration volume elements are evaluated. The numerical results are compared with the experimental results which confirm the acceptable accuracy of the performed numerical analysis.

Key words : Toughening mechanism, recycled rubber composite, glass bubbles, homogenization,representative volume element, periodic boundary conditions

Thesis defence : monday 26 june 2023 
Composition of the jury : 

Mr Mohamed HABOUSSI, Rapporteur, Université Paris 13 Nord

Mr Dimitar DONTCHEV, Rapporteur, University of Chemical Technology and Metallurgy 

Mr Emin BAYRAKTAR, Thesis supervisor, ISAE-Supméca - Institut Supérieur de Mécanique de Paris

Mr Ozgur ASLAN, Thesis co-director, Atilim University

Ms Olga KLINKOVA, Examinatrice, ISAE-Supméca - Institut Supérieur de Mécanique de Paris

Mr Philippe VIDAL, Examinateur, Université Paris Nanterre

Mr Georges ZAMBELIS, Examinateur, SAFRAN GROUP, Innovative Composite Research Centre

Ms Sophie CANTIN, Examinatrice, CY Cergy Paris Université

Ms Ivelina IVANOVA, Guest, Université de Reims Champagne-Ardenne