Rotary Nonlinear Energy Sinks for Beam Vibration Passive Suppression

• Grant number: 24/08286-5
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: October 18, 2024
• End date: April 17, 2025
• Field of knowledge: Engineering - Mechanical Engineering
• Principal Investigator: Flávio Donizeti Marques
• Grantee: Gabriel Placeres Araujo
• Supervisor: Walter Lacarbonara
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Institution abroad: Università degli Studi di Roma La Sapienza, Italy
• Associated to the scholarship: 23/15207-1 - Multiple Degree of Freedom Nonlinear Energy Sink for Flutter Passive Control, BP.MS

Abstract

Structural dynamics is an important topic in several engineering fields once dynamic loading becomes a reality in most applications, which can lead to instability or fatigue in components, compromising their operability. Several active and passive methods for controlling unwanted vibrations have been developed over the years. Among them, passive control is promising because it does not depend on external electric sorce.In this sense, Nonlinear Energy Sinks devices have been extensively reported in recent literature as passive control techniques. These devices consist of a vibration absorber in which a secondary mass is nonlinearly attached to the main structure. Their suppression mechanism is based on Targeted Energy Transfer, in which energy is pumped from structural vibration to the secondary mass for fast and irreversible dissipation. Their main advantage is that they are able to resonate at any excitation frequency, thus maintaining performance at broader operation ranges compared to linear tuned absorbers.A particular device configuration is the rotary Nonlinear Energy Sink, which is based on a horizontal pendulum attached to the structure, freely able to rotate and absorb energy. This design allows a purely nonlinear inertial coupling to the host structure, being of simple design and concept, although of complex dynamics. A viscous angular damping is considered on its axis in order to model the energy dissipation and allow the TET phenomenon to passively suppress structural vibration. This device does not consider potential energy in the model, with a pure nonlinear transference of structural energy in the form of kinetic energy on the secondary mass. Rotary Nonlinear Energy Sinks have been proposed for the control of Fluid-Induced Vibrations, such as vortex-induced vibrations and flutter, as well as seismic attenuation and multiple degree of freedom structures.Vibration control of beam structures poses an interesting subject since beam elements are fundamental components of numerous structures, from civil and mechanical backgrounds to aeronautical structures. The attachment of Nonlinear Energy Sinks for beam vibration suppression is largely reported and with crescent interest due to metastructure applications. Yet, mostly polynomial and vibro-impact nonlinearities have been explored. To the best of the authors knowledge, the attachment of a purely inertial rotary Nonlinear Energy Sink for beam passive suppression still hasn't been explored, and poses an interesting subject due to its relatively simple design.This Research Internship Abroad project proposes the study of the attachment of rotary Nonlinear Energy Sinks for beam vibration passive suppression. A linear beam model will be developed based on a finite element approach and dissipative devices will be placed on element nodes. The study will be carried out through numeric simulations of the mathematical model for one or multiple absorber configurations, comprising an analysis of suppression performance and a design parametric analysis. Depending on the development of the project, analytical or numeric continuation methods might be explored to characterize the complex nonlinear dynamics of the system.