Professor Steven W. Shaw Steven W. Shaw is Professor of Mechanical Engineering at Florida Institute of Technology.  He is also Adjunct Professor of Physics and Astronomy and University Distinguished Professor Emeritus of Mechanical Engineering at Michigan State University.  He received an AB in Physics (1978) and an MSE in Applied Mechanics (1979) from the University of Michigan and a PhD in Theoretical and Applied Mechanics (1983) from Cornell University. His current research interests include vibration absorbers and micro/nano-scale resonators, with an emphasis on nonlinear and noisy behavior and applications to timekeeping, sensing, and torsional vibrations.  He has held visiting appointments at Cornell University, the University of Michigan, Caltech, the University of Minnesota, the University of California-Santa Barbara, and McGill University.  Steve is a Fellow of ASME (1995) and recipient of the Henry Ford Customer Satisfaction Award (1986), the ASME Henry Hess Award (1986), the SAE Arch T. Colwell Merit Award (1997), the ASME N. O. Myklestad Award (2013), the ASME T. K. Caughey Dynamics Award (2019), and the ASME J. P. Den Hartog Award (2023).

Reducing Torsional Vibration Using Order Tuned Absorbers – Theory and Applications

Centrifugal pendulum vibration absorbers consist of masses that are movably suspended to a rotor in a manner such that their response under the action of the rotor dynamics reduces engine-order torsional vibrations.  These devices have been in wide use in light aircraft engines since the 1930’s and recently have seen extensive application in automotive powertrain components where they are used to improve fuel economy and enhance passenger comfort.  There is a long history of investigations of these absorbers that includes detailed analyses of the paths along which the absorbers travel relative to the host rotor.  This path dictates linear and nonlinear pendulum tuning and plays an essential role in absorber effectiveness.  Theoretical and experimental studies have solidified our understanding of these systems and provided approaches for designing paths to optimize performance.  In this presentation I will review this history and discuss some recent developments that have enhanced the use of pendulum absorbers.  These include: (i) the dynamics of absorbers immersed in fluid, such as those used in automotive torque converters, and (ii) the design of absorbers that rotate relative to the host rotor to enhance their effective inertia.  Absorber tuning strategies that account for these effects will be presented.  Finally, difficulties associated with implementing these absorbers for other applications, such as the gear systems used in electric vehicles, will also be briefly discussed.