scholarly journals Optimum Design of a Nonlinear Vibration Absorber Coupled to a Resonant Oscillator: A Case Study

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
H. F. Abundis-Fong ◽  
J. Enríquez-Zárate ◽  
A. Cabrera-Amado ◽  
G. Silva-Navarro
Keyword(s):  
Multiple Scales ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Parametric Uncertainty ◽  
Vibration Absorber ◽  
Nonlinear Frequency ◽  
Nonlinear Absorber ◽  
Nonlinear Frequency Response ◽  
Active Vibration ◽  
Mass Spring

This paper presents the optimal design of a passive autoparametric cantilever beam vibration absorber for a linear mass-spring-damper system subject to harmonic external force. The design of the autoparametric vibration absorber is obtained by using an approximation of the nonlinear frequency response function, computed via the multiple scales method. Based on the solution given by the perturbation method mentioned above, a static optimization problem is formulated in order to determine the optimum parameters (mass and length) of the nonlinear absorber which minimizes the steady state amplitude of the primary mass under resonant conditions; then, a PZT actuator is cemented to the base of the beam, so the nonlinear absorber is made active, thus enabling the possibility of controlling the effective stiffness associated with the passive absorber and, as a consequence, the implementation of an active vibration control scheme able to preserve, as possible, the autoparametric interaction as well as to compensate varying excitation frequencies and parametric uncertainty. Finally, some simulations and experimental results are included to validate and illustrate the dynamic performance of the overall system.

Passive/Active Autoparametric Cantilever Beam Absorber With Piezoelectric Actuator for a Two-Story Building-Like Structure

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Gerardo Silva-Navarro ◽  
Hugo F. Abundis-Fong
Keyword(s):  
Cantilever Beam ◽  
Active Vibration Control ◽  
Parametric Uncertainty ◽  
Vibration Absorber ◽  
Primary System ◽  
Internal Resonances ◽  
Piezoelectric Patch ◽  
Active Vibration ◽  
Stiffness And Damping ◽  
Story Building

This work deals with the design and experimental evaluation of a passive/active cantilever beam autoparametric vibration absorber mounted on a two-story building-like structure (primary system), with two rigid floors connected by flexible columns. The autoparametric vibration absorber consists of a cantilever beam with a piezoelectric patch actuator, cemented to its base, mounted on the top of the structure and actively controlled through an acquisition system. The overall system is then a coupled nonlinear oscillator subjected to sinusoidal excitation in the neighborhood of its external and internal resonances. The addition of the piezoelectric patch actuator to the cantilever beam absorber makes active the passive vibration absorber, thus enabling the possibility to control its equivalent stiffness and damping and, as a consequence, the implementation of an active vibration control scheme able to preserve, as possible, the autoparametric interaction as well as to compensate varying excitation frequencies and parametric uncertainty.

Design of a Passive/Active Autoparametric Cantilever Beam Absorber With PZT Actuator for a Building-Like Structure

2013 ◽  
Author(s):  
H. F. Abundis-Fong ◽  
G. Silva-Navarro ◽  
B. Vazquez-Gonzalez
Keyword(s):  
Cantilever Beam ◽  
Primary Structure ◽  
Internal Resonance ◽  
Active Vibration Control ◽  
Parametric Uncertainty ◽  
Vibration Absorber ◽  
Control Scheme ◽  
Active Vibration ◽  
Stiffness And Damping ◽  
Sinusoidal Excitation

An experimental and theoretical investigation is carried out on a system consisting of a primary structure coupled with a passive/active autoparametric vibration absorber. The primary structure consists of a building-like mechanical structure with two rigid floors connected by flexible columns made from aluminium strips, while the vibration absorber consists of a cantilever beam with a PZT patch actuator cemented and actively controlled through an acquisition card installed on a PC running on a Matlab/Simulink platform. The overall system is then a coupled nonlinear oscillator subjected to sinusoidal excitation, obtained from an electromechanical shaker, in the neighborhood of its external and internal resonance. The addition of the PZT patch actuator to the cantilever beam absorber, cemented to the base of the beam, makes active the autoparametric vibration absorber, thus enabling the possibility to control the effective stiffness and damping associated to the passive absorber and, as a consequence, the implementation of an active vibration control scheme able to preserve, as possible, the autoparametric interaction as well as to compensate varying excitation frequencies and parametric uncertainty.

Study of plate vibrating in fluids having part-through crack at random angles and locations

2021 ◽  
pp. 095440622110127
Author(s):  
Ruqia Ikram ◽  
Asif Israr
Keyword(s):  
Frequency Response ◽  
Multiple Scales ◽  
Peak Amplitude ◽  
Nonlinear Frequency ◽  
Response Curves ◽  
Crack Location ◽  
Cracked Plate ◽  
Nonlinear Frequency Response ◽  
Angle Crack ◽  
Crack Angle

This study presents the vibration characteristics of plate with part-through crack at random angles and locations in fluid. An experimental setup was designed and a series of tests were performed for plates submerged in fluid having cracks at selected angles and locations. However, it was not possible to study these characteristics for all possible crack angles and crack locations throughout the plate dimensions at any fluid level. Therefore, an analytical study is also carried out for plate having horizontal cracks submerged in fluid by adding the influence of crack angle and crack location. The effect of crack angle is incorporated into plate equation by adding bending and twisting moments, and in-plane forces that are applied due to antisymmetric loading, while the influence of crack location is also added in terms of compliance coefficients. Galerkin’s method is applied to get time dependent modal coordinate system. The method of multiple scales is used to find the frequency response and peak amplitude of submerged cracked plate. The analytical model is validated from literature for the horizontally cracked plate submerged in fluid as according to the best of the authors’ knowledge, literature lacks in results for plate with crack at random angle and location in the presence of fluid following validation with experimental results. The combined effect of crack angle, crack location and fluid on the natural frequencies and peak amplitude are investigated in detail. Phenomenon of bending hardening or softening is also observed for different boundary conditions using nonlinear frequency response curves.

Effects of Actuators and Sensors Position on Independent Modal Control Performance

2012 ◽  
Author(s):  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Natural Frequencies ◽  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Point Of View ◽  
Control Technique ◽  
Modal Control ◽  
Sensors And Actuators ◽  
Active Vibration

Independent modal control technique allows to change the eigenvalues of a system, without changing its eigenvectors. From a mechanical point of view, it means it is possible to modify the natural frequencies and the damping of a n-DoF system, letting modal shapes unchanged. Independent modal control can be profitably used in active vibration control increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. This work demonstrates how the performance of the control depends on the number and position of sensors and actuators used besides, obviously, on the reduced model used to synthesize the control itself. Finally the paper suggests a simple optimum function to minimize the spillover effects due to unmodeled modes. Theoretical aspects are supported by numerical simulations.

Vibration Reduction in Large Flexible Systems Through Independent Modal Control

2011 ◽  
Author(s):  
Francesco Braghin ◽  
Simone Cinquemani ◽  
Ferruccio Resta
Keyword(s):  
Acoustic Noise ◽  
Dynamic Performance ◽  
Active Vibration Control ◽  
Spillover Effects ◽  
Flexible System ◽  
Damping Matrix ◽  
Modal Damping ◽  
Active Vibration ◽  
The Stability ◽  
Modal Controller

Many systems have, by their nature, a small damping and therefore they are potentially subjected to dangerous vibration phenomena. The aim of active vibration control is to contain this phenomenon, increasing the damping of the system without changing its natural frequencies and vibration modes. A control of this type can improve the dynamic performance, reduce the vibratory phenomenon (and the resulting acoustic noise) and increase the fatigue strength of the system. The paper introduces a new approach to the synthesis of a modal controller to suppress vibrations in structures: it turns from the traditional formulation of the problem showing how the performance of the designed controller can be evaluated through the analysis of the resulting modal damping matrix of the controlled system. Such analysis allows to evaluate spillover effects, due to the presence of un-modeled modes, the stability of the control and the consequent effectiveness in reducing vibration. The ability to easily manage this information allows the synthesis of an efficient modal controller. Theoretical aspects are supported by experimental applications on a large flexible system.

Nonlinear Frequency Response Analysis of a Multistage Clutch Damper With Multiple Nonlinearities

2014 ◽  
Vol 9 (3) ◽  
Author(s):  
Jong-Yun Yoon ◽  
Hwan-Sik Yoon
Keyword(s):  
Frequency Response ◽  
Harmonic Balance ◽  
Piecewise Linear ◽  
Dynamic Performance ◽  
Harmonic Balance Method ◽  
Balance Method ◽  
Response Analysis ◽  
Nonlinear Frequency ◽  
System Equation ◽  
Nonlinear Frequency Response

This paper presents the nonlinear frequency response of a multistage clutch damper system in the framework of the harmonic balance method. For the numerical analysis, a multistage clutch damper with multiple nonlinearities is modeled as a single degree-of-freedom torsional system subjected to sinusoidal excitations. The nonlinearities include piecewise-linear stiffness, hysteresis, and preload all with asymmetric transition angles. Then, the nonlinear frequency response of the system is numerically obtained by applying the Newton–Raphson method to a system equation formulated by using the harmonic balance method. The resulting nonlinear frequency response is then compared with that obtained by direct numerical simulation of the system in the time domain. Using the simulation results, the stability characteristics and existence of quasi-harmonic response of the system are investigated. Also, the effect of stiffness values on the dynamic performance of the system is examined.

Dielectric Elastomer Actuators as Elements of Active Vibration Control Systems

2008 ◽  
Vol 61 ◽  
pp. 103-111 ◽  
Author(s):  
Fotis G. Papaspiridis ◽  
I.A. Antoniadis
Keyword(s):  
Vibration Control ◽  
Control Systems ◽  
Active Vibration Control ◽  
Dielectric Elastomer ◽  
Large Strains ◽  
New Class ◽  
Dielectric Elastomer Actuators ◽  
Active Vibration ◽  
Spring System ◽  
Mass Spring

Dielectric elastomer actuators (DEA) are a new class of actuators, exhibiting electric field-induced strains. Upon electrical stimulation they can provide large strains and consequently electrical forces. These abilities along with their high compliance make them candidates for active vibration control. This parer presents a general framework for the usage of DEA as elements of active vibration control systems. The electrical and mechanical model of the DEA and a basic control law, for varying the voltage, is reviewed. The basic idea is to reduce the acceleration of the vibrating equipment when the system approaches its equilibrium. The application of the actuator in a single-dof-mass-spring system is modeled. The results with and without control are presented and show the large capabilities of the actuator to suppress the vibrations induced by an external force. DEA has viscoelastic properties, which can further increase the damping capabilities of the vibration absorber but on the other hand produce a time delay, which must be taken into account. Furthermore, the technological issues arisen -structure of the actuator, power and equipment needs, effect of prestrain and frequency, distributed actuation- are discussed.

Nonlinear vibration of magnetoelectroelastic nanoscale shells embedded in elastic media in thermoelectromagnetic fields

2019 ◽  
Vol 30 (15) ◽  
pp. 2331-2347 ◽  
Author(s):  
Yan Qing Wang ◽  
Yun Fei Liu ◽  
Jean W Zu
Keyword(s):  
Nonlinear Vibration ◽  
Multiple Scales ◽  
Nonlocal Parameter ◽  
Nonlocal Elasticity Theory ◽  
Nonlinear Ordinary Differential Equation ◽  
Elastic Media ◽  
Nonlinear Frequency ◽  
Governing Equations ◽  
Nonlinear Frequency Response ◽  
The Galerkin Method

This study investigates the nonlinear vibration of magnetoelectroelastic composite cylindrical nanoshells embedded in elastic media for the first time. The small-size effect and thermoelectromagnetic loadings are considered. Based on the nonlocal elasticity theory and Donnell’s nonlinear shell theory, the nonlinear governing equations and the corresponding boundary conditions are derived using Hamilton’s principle. Then, the Galerkin method is utilized to transform the governing equations into a nonlinear ordinary differential equation and subsequently the method of multiple scales is employed to obtain an approximate analytical solution to nonlinear frequency response. The present results are verified by the comparison with the published ones in the literature. Finally, an extensive parametric study is conducted to examine the effects of the nonlocal parameter, the external magnetic potential, the external electric potential, the temperature change, and the elastic media on the nonlinear vibration characteristics of magnetoelectroelastic composite nanoshells.

Sign in / Sign up

Export Citation Format

Share Document