Pearl Sullivan
PEng, CEng

BEng, MASc (TUNS), PhD (British Columbia)

Professor and Chair, Department of Mechanical and Mechatronics Engineering 

Laboratories:

Research  Interests:

Advanced Polymers and Composites, Micro-Engineering, Adhesive Bonding, Smart Structures

(i) Polymers and their Composites

Although polymers and their composites are increasingly becoming the mainstream materials in engineering design, their long-term stability under combined thermo-mechanical loads is still not well characterized. This is because the response of these materials evolve over time for two reasons: (i) their inherent molecular structure leads to mechanical properties that are viscoelastic, i.e. time- and temperature-sensitive; and (ii) the release of residual stresses formed during high volume manufacturing, such as injection molding, resulting in dimensional changes. Both effects can profoundly affect the integrity and performance of the part. More important, with the growing trend towards miniaturization in advanced technologies, polymeric products are increasingly smaller with thinner walls. Innate volumetric changes in these small parts pose problems especially in tight-tolerance applications as they lead to part warpage.

This research program involves the characterization and modeling of the thermo-mechanical behaviour of a wide spectrum of polymer-based materials ranging from structural adhesives used in building high performance aircraft to thermoplastic welds in optoelectronics packaging. The developed constitutive models are then implemented into a commercial finite element analysis (FEA) package to enable the designer to predict part performance. An emerging area from this core research capability is related to micro-engineering which aims to model the divergence of thermo-mechanical properties from their bulk values as dimensions are reduced.

(ii) Adhesive bonding of dissimilar joints

One of the major technical challenges in using different materials to fabricate engineering structures is how to join them. This research specifically addresses the emerging problem in aerospace, automotive and electronics applications where lightweight, high-stiffness and strong polymeric composites are increasingly being used to replace metals. Recent projects include the repair of aging aircraft that involves designing a process for adhesively bonding a carbon-fibre composite component onto the metallic parent structure. There is interest in extending this technology for the development of lightweight wind turbines.

(iii) Development of smart structures

The smart structures program is strongly coupled with both the composites and adhesive bonding programs. The concept of applying in-situ health monitoring technology within engineering structures is very attractive from a maintenance standpoint. Recent work has embedded a distributed fiber optic sensor within laminated composite materials for cure monitoring as a first step for developing a passive smart structure. Future work will extend this embedded sensing capability for damage detection within the structure when subjected to external loading as well as evaluate the capabilities of new film sensors.

Journal Publications

 

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Last updated:  November 1, 2004.