University Affiliates

Current research interests range from the molecular dynamics of mechanical relaxation of polymers to the high-speed, low-cost manufacturing of fiber composite structures and includes fracture processes in polymers and composites and failure analysis. Related to mechanical relaxation is the physical aging of polymer glasses. The nature of molecular motion in polymer glasses and the parameters that control the kinetics of physical aging are being studied. The goal is to be able to predict aging rates at normal service temperatures where experimental measurements would take too long. Current study of fracture processes ranges from fundamental studies of the mechanisms of crack propagation in brittle materials to the use of fracture in fiber composite structures for crash energy absorption. Research into high-speed, low-cost fiber composite structure manufacturing involves several problems of the "liquid molding" process, in which liquid resin is injected into a closed mold containing a fiber preform. The problems being studied are the design and manufacture of the fiber preform and the displacement of air and the wetting of the fibers by the injected resin. A related problem being studied is the repair of such composite structures after damage