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Active Local Volume Displacement Cancellation Of A Vibrating Baffled Beam, Marcellin Zahui

Dissertations

An active noise control apparatus is developed. The device reduces the sound radiated from a vibrating clamped beam. The attenuation of the sound field is obtained through minimization of local volume displacements of the vibrating beam. Two single-input/single-output cancellation devices are used. Each device employs a motion sensor and an acoustic actuator. The actuator is a loudspeaker equipped with a pressure sensor to detect its volume displacement. The motion sensor signal is related to the local volume displacement of the structure which is then reduced by a loudspeaker driven with an equal but opposing volume displacement. The volume displacement sensors …

Investigation Of Thermal Contact Resistance At A Plastic-Metal Interface In Injection Molding, Lakshminarayanan Sridhar

Dissertations

Thermal contact resistance (TCR) at the plastic-metal interface is one of the parameters required for the simulation of plastic processing techniques such as injection molding. However, the available data is both unreliable and insufficient due to the difficulties involved in measuring this parameter. The effects of thermal contact resistance on the heat transfer in plastics processing with particular reference to injection molding of thermoplastics is investigated using combined experimental measurement techniques, parametric studies and numerical analysis.

TCR under steady state conditions has been determined experimentally at typical thermoplastic-mold metal interfaces for an amorphous and a semi-crystalline polymer using a one-dimensional …