Martine Dubé
Professor
Department of Mechanical Engineering
Martine Dubé
Composite Materials
Composite materials are increasingly being used in various sectors of industry due to their high specific properties and the possibility of components integration. By combining reinforcements and matrices, a set of physical and mechanical properties is obtained, which would be impossible by taking the components separately. The composite materials that I study are made of fibre reinforcement (carbon, glass or natural fibre) and polymeric matrices. My research is focused on joining and repairing of high performance composites as well as bio-composites.

Welding of Thermoplastic Composites
Thermoplastic polymers offer some advantages over thermosetting polymers. Among these advantages, are their shorter processing cycle, better resistance to environment and the possibility to process the polymers more than one time. The latter allows for joining of thermoplastic composites by welding (as opposed to mechanical fastening or adhesive bonding). The welding method that I investigated in the past is resistance welding. This method consists in applying a heating element between two adherends to be welded. The heating element must be an electrical conductor and it must also be porous. The ends of the heating element are connected to a power supply and electrical current is introduced to the heating element. As the current passes in the heating element, temperature increases and the adjoining polymer matrix melts and flows. When a pre-determined temperature is reached, the current is stopped and the polymer solidifies, under the application of pressure, resulting in a welded joint. My Ph.D. thesis at McGill University under the supervision of Professor Pascal Hubert presents the work that I have done on this subject. My present research focuses on resistance and induction welding.
 
Repair of Thermoplastic Composites
Composite materials being used in aerospace structural applications, repair methods must be developed for these materials, with the objective of restoring the initial mechanical properties of the structure. Repair methods were developed for thermosetting composites, in whcih the damaged plies are removed and replaced by new pre-impregnated plies. The new plies are then cured under the application of heat and pressure. My research on this subject focuses on the development of repair methods for thermoplastic composites, taking into account the possibility of welding.


Contact info

Office: A-1918
Phone: 514 396-8487
Fax: 514 396-8530

martine.dube@etsmtl.ca