The goal of this Grant Opportunity for Academic Liaison with Industry (GOALI) project is to investigate dynamic interactions in systems composed of multiple vibration absorbers that are tuned to different frequencies. Most tuned absorber devices are designed to reduce vibrations near a given frequency, typically to suppress the resonance of a troublesome vibration mode. If one uses a set of absorbers tuned to different frequencies, for example, to address multiple vibration modes, nonlinear dynamic interactions between absorbers can occur, causing a significant reduction in the effectiveness of the absorber system. Thus, optimal design of multi-frequency absorber systems requires a fundamental understanding of these interactions, so that they can be avoided. The research program is aimed at developing this knowledge base and implementing it to reduce multi-frequency automotive powertrain torsional vibrations that occur, for example, in engines that employ cylinder deactivation. The approach involves a combination of physical modeling, analysis by perturbation methods and computer simulations, experimental verification, and development of guidelines for meeting performance specifications by selection of absorber system parameters, specifically, tunings and inertias.
The results obtained will extend the knowledge base for vibration absorbers to situations with multi-frequency excitations, which will allow for improved effectiveness of absorber systems over a wide range of operating conditions. The university and industrial partners will work in close cooperation to develop absorber systems that will facilitate the implementation of fuel-saving technologies for automotive engines, by allowing them to operate in regimes with high efficiency that are otherwise plagued with vibration problems. The results of the research will be made widely accessible by technical publications and presentations. The research activity will also be described, in the general context of energy conservation technologies, by the university PIs and their graduate students in summer outreach programs geared to middle and high school students.
