We are pleased to announce the seminar of  

Tokannou-Willy-Rodrigue AMOUSSOU, on "Development of new processes and composite materials adopted for the hybridization of structural parts in the automotive field."

On  8/02/2024 at 13h15  via Teams. 

Abstract : 

The objective of this thesis is to develop innovative composites and a new process that are applicable especially to the hybridization of a door box type part (skin + structure) and in general to body-in-white parts and thus allowing lightening mass-produced vehicles. As a result, for the duration of this one, we conducted a study on composite materials, in order to replace stamped steel sheets or to develop hybrid parts (steel and composites).

At first, we conceived a method of production by thermoforming using the Joule heating effect induced by the resistivity of carbon fibre. We have, then, conducted a mechanical study of a composite made of carbon fibre and polyamide 66 (nylon-66). Made of three plies, with a thickness of 0.2 mm each, the taffeta woven composite has shown excellent mechanical properties, far superior from steel. Afterward, we have carried out a vibration study to make sure it was respecting the specification imposed. The door box has shown (in the three configurations : free, opened, and closed) a frequency mode close to 33 Hz. Later, a crack growth study revealed that fibre with an angle at 45° to the crack growth direction, oppose a great resistance to the propagation of the crack.

At the second, we carried out a reconceive of the door box in carbon and nylon-66. This study allowed us to realize that the part cannot be entirely made of composite material. Therefore, we proposed to make it in hybrid materials combining DX57D steel and PA 66 carbon composite. We then conducted FEM simulations (for different load cases) and damage to the defined composite material. This study allowed us to validate the feasibility of the door box in hybrid materials. We also considered the type of assembly to adopt for its mass production.

Finally, a validation study of composite made of carbon fibre and PA66 was carried out, which allowed us to quantify the mass gain, to evaluate its environmental impact and cost, and to realize that the production of the composite can be performed without depending on the petrochemical industry and has excellent recycling capabilities.