Targeted Energy Transfer and Modal Energy Redistribution in Automotive Drivetrains

The new generations of compact high output power-to-weight ratio internal combustion engines generate broadband torsional oscillations, transmitted to lightly damped drivetrain systems. A novel approach to mitigate these untoward vibrations can be the use of nonlinear absorbers. These act as Nonlinear Energy Sinks (NESs). The NES is coupled to the primary (drivetrain) structure, inducing passive irreversible targeted energy transfer (TET) from the drivetrain system to the NES. During this process, the vibration energy is directed from the lower-frequency modes of the structure to the higher ones. Thereafter, vibrations can be either dissipated through structural damping or consumed by the NES. This paper uses a lumped parameter model of an automotive driveline to simulate the effect of TET and the assumed modal energy redistribution. Significant redistribution of vibratory energy is observed through TET. Furthermore, the integrated optimization process highlights the most effective configuration and parametric evaluation for use of NES

APPROXIMATION OF THE FREQUENCY-ENERGY DEPENDENCE IN THE NONLINEAR DYNAMICAL SYSTEMS

ABSTRACT In this work, a method is introduced for extracting the approximate backbone branches of the frequency-energy plot INTRODUCTION The nonlinear dynamical oscillators have been extensively studied in the literature where several methods and techniques have been applied to approximate their periodic solutions and nonlinear frequencies. Most of the publications in this field have focused on the nonlinear oscillators of odd-power stiffness component

Data for: New Backward Whirl Phenomena in Intact and Cracked Rotor Systems

The folder includes Matlab codes and data which are related to some results in the manuscriptTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

IMECE 2008-66555 USE OF NONLINEAR VIBRATION FREQUENCIES AND ELECTRICAL CONDUCTIVITY MEASUREMENTS IN THE SEPARATION OF INTERNAL AND BOUNDARY DAMAGE IN STRUCTURES

ABSTRACT The paper addresses one of the key problems in structural health monitoring -how to separate defects, both microscopic and macroscopic, accumulated in structural members from damage in the joints and boundaries. It is suggested to use a simultaneous set of measurements -nonlinear vibration frequencies and electrical conductivities -to distinguish between three distinct types of defects. Nonlinearities occur as a result of breathing internal cracks and slapping in damaged joints. The use of proper orthogonal decomposition and a local equivalent linear stiffness method allows for model updating to account for the damage. The theory is presented for full threedimensional elastic solids and illustrated via the problem of a beam damaged both internally as well as at the boundaries