Nonlinear modeling and vibration mitigation of combined vortex-induced and base vibrations through energy harvesting absorbers

This study derives a nonlinear reduced-order model in order to evaluate the efficacy of an energy harvesting absorber at controlling base excitations, vortex-induced vibrations, and simultaneous base excitations and vortex-induced vibrations. Vibration absorbers are secondary systems that couple with a primary structure to dissipate the mechanical energy of vibrations. An energy harvesting absorber turns a portion of that dissipated energy into useful electrical energy which can be used to power small systems. The effects of various design parameters of the energy harvesting absorber on the behavior of the system is examined under different excitations. Next, an investigation of increasing the stiffness of the absorber is carried out with a goal of increasing the range in which meaningful energy can be harvested. Designs for the energy harvesting absorber are compared for their control of the system and their energy output when the system is subjected to concurrent base excitations and vortex-induced vibrations. Using an energy harvesting absorber tuned for vortex-induced vibrations provides the greatest reduction in amplitude and the most even power output over the range of wind speeds and base excitations. (C) 2020 Elsevier B.V. All rights reserved.