[cid:image005.png@01CB8FBC.5FE94DA0] Mechanical Engineering Graduate Seminar [cid:image006.jpg@01CB8FBC.5FE94DA0] Thursday, December 2, 2010, ME 161 4:30 p.m. Torsional Vibration Absorbers for Rotating Machinery - from Symmetric Bifurcations to Advanced Engine Technologies Steven W. Shaw Department of Mechanical Engineering Michigan State University East Lansing, MI 48824 Abstract In this seminar I will describe results from our research on centrifugal pendulum vibration absorbers, which are used to attenuate engine-order torsional vibrations in rotating machines. These absorbers are well suited for reducing automotive powertrain vibrations, which are particularly troublesome during low-speed high-torque operation. One can improve fuel economy by attenuating these vibrations, for example, by enhancing low-speed torque converter lockup, or expanding operating ranges for cylinder deactivation in variable displacement engines. This presentation will explain the basic operation of pendulum absorbers, provide an overview of their rich nonlinear behavior (which includes symmetry related dynamic instabilities), and demonstrate how one can use our fundamental understanding of their dynamic response to help design effective absorber systems. I will outline our contributions to both basic and applied research, which includes predictive analysis, computer simulations, controlled experiments, and successful tests on automotive engines. Acknowledgements: This work is carried out jointly with MSU Professors Alan Haddow and Brian Feeny, MSU graduate students Ryan Monroe and Brendan Vidmar, and Dr. Bruce Geist of Chrysler Group LLC. The work is currently funded by an NSF GOALI project and Chrysler Challenge Funds. Short Bio Steven W. Shaw is a Professor in the Department of Mechanical Engineering at Michigan State University. He received an A.B. in Physics (1978) and an M.S. in Applied Mechanics (1979) from the University of Michigan and a Ph.D. in Theoretical and Applied Mechanics (1983) from Cornell University. He has held visiting appointments at Cornell, the University of Michigan, Caltech, the University of Minnesota, the University of California-Santa Barbara, and McGill University. His interests are in dynamical systems and mechanical vibrations, with applications to vibration absorbers, micro- and nano-scale resonators, and structural vibrations. Steve currently serves in editorial capacities for the ASME Journal of Vibration and Acoustics and Nonlinear Dynamics. He is a Fellow of ASME and recipient of the ASME Henry Hess Award (1986), the SAE Arch T. Colwell Merit Award (1997), and the MSU Distinguished Faculty Award (2008). Refreshments will be served at 4:00 p.m. in Room 254