scholarly journals Subordinate Oscillator Arrays: Physical Design and Effects of Error

2020 ◽  
Author(s):  
John Sterling ◽  
Sai Tej Paruchuri ◽  
Teresa Jean Ryan ◽  
Joseph Vignola ◽  
Andrew J. Kurdila
Keyword(s):  
Frequency Response ◽  
Design Strategy ◽  
Optimization Techniques ◽  
Vibration Absorbers ◽  
Classical Dynamic ◽  
Computational Optimization ◽  
Highly Sensitive ◽  
Judicious Choice ◽  
Host Structure ◽  
Oscillator Arrays

Prior work demonstrates that an attached subordinate oscillator array (SOA) can attenuate vibration of a host structure over a frequency range of interest. A judicious choice of the distribution of masses and stiffnesses of the attached oscillators can result in a relatively flat frequency response of for the host structure over a desired band. This response modification can be a significant improvement over classical dynamic vibration absorbers (DVA) that attenuate a structure's response at one target frequency while increasing the frequency response amplitude at nearby side frequencies. Performance of the SOA can be highly sensitive to the uncertainty or disorder in the mechanical properties of the system. This paper introduces a novel design strategy that can make use of either 3D-printing or piezoelectric SOAs (PSOAs). These strategies have the potential to address and ameliorate such sensitivity to error. It is important to note that the design strategy is simple and effective in that it can be carried out without computational optimization techniques by choosing simple or well-known distributions of properties.

Piezoelectric Subordinate Oscillator Arrays: Performance Recovery and Robustness to Uncertainty

2019 ◽  
Author(s):  
John Sterling ◽  
Sai Tej Paruchuri ◽  
Pablo Tarazaga ◽  
Joseph Vignola ◽  
Andrew Kurdila ◽  
...  
Keyword(s):  
Frequency Response ◽  
Design Strategy ◽  
Optimization Techniques ◽  
Vibration Absorbers ◽  
Electromechanical Properties ◽  
Classical Dynamic ◽  
Highly Sensitive ◽  
Performance Recovery ◽  
Dynamic Vibration Absorbers ◽  
Oscillator Arrays

Abstract Prior work demonstrates that an attached subordinate oscillator array (SOA) can attenuate vibration of a host structure. The distribution of masses and stiffnesses of the attached oscillators can craft a flat frequency response over a desired band. This response modification can be a significant improvement over classical dynamic vibration absorbers (DVA) that attenuate response at one target frequency while increasing the frequency response amplitude at nearby side frequencies. Performance of the SOA can be highly sensitive to the uncertainty or disorder in the mechanical properties of the system. This paper shows that use of piezolectric SOAs (PSOAs) has the potential to address and ameliorate such sensitivity to off-design situations. It is important to note that the design strategy is simple and effective: it can be carried out without optimization techniques by choosing simple or well-known distributions of electromechanical properties.

scholarly journals Proposal of optimal operation strategy applied to water distribution network with statistical approach

2020 ◽  
Vol 15 (2) ◽  
pp. 1
Author(s):  
Alex Takeo Yasumura Lima Silva ◽  
Fernando Das Graças Braga da Silva ◽  
André Carlos da Silva ◽  
José Antonio Tosta dos Reis ◽  
Claudio Lindemberg de Freitas ◽  
...  
Keyword(s):  
Genetic Algorithms ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Optimal Operation ◽  
Optimization Techniques ◽  
Experimental Techniques ◽  
Computational Optimization ◽  
Depth Analysis

 Inefficiency of sanitation companies’ operation procedures threatens the population’s future supplies. Thus, it is essential to increase water and energy efficiency in order to meet future demand. Optimization techniques are important tools for the analysis of complex problems, as in distribution networks for supply. Currently, genetic algorithms are recognized by their application in literature. In this regard, an optimization model of water distribution network is proposed, using genetic algorithms. The difference in this research is a methodology based on in-depth analysis of results, using statistics and the design of experimental tools and software. The proposed technique was applied to a theoretical network developed for the study. Preliminary simulations were accomplished using EPANET, representing the main causes of water and energy inefficiency in Brazilian sanitation companies. Some parameters were changed in applying this model, such as reservoir level, pipe diameter, pumping pressures, and valve-closing percentage. These values were established by the design of experimental techniques. As output, we obtained the equation of response surface, optimized, which resulted in values of established hydraulic parameters. From these data, the obtained parameters in computational optimization algorithms were applied, resulting in losses of 26.61%, improvement of 16.19 p.p. with regard to the network without optimization, establishing an operational strategy involving three pumps and a pressure-reducing valve.  We conclude that the association of optimization and the planning of experimental techniques constitutes an encouraging method to deal with the complexity of water-distribution network optimization.

Design of Pendulum Absorbers for Transverse Vibration Attenuation of Rotating Beams

1997 ◽  
Author(s):  
Yenkai Wang ◽  
Steven W. Shaw ◽  
Chang-Po Chao
Keyword(s):  
Transverse Vibration ◽  
Design Strategy ◽  
Simplified Model ◽  
Vibration Absorbers ◽  
Rotating Beam ◽  
External Excitation ◽  
Rotating Beams ◽  
Transverse Vibrations ◽  
Vibration Attenuation ◽  
Centrifugal Pendulum Vibration Absorbers

Abstract This paper considers the placement, sizing and tuning of centrifugal pendulum vibration absorbers for the reduction of transverse vibrations in rotating beams. A simplified model describing the linearized dynamics of a rotating beam with external excitation and attached absorbers is used for the analysis. A design strategy is offered wherein individual absorbers are designed to reduce vibration amplitudes and stress levels caused by troublesome resonances. It is shown that this procedure offers significant reduction in vibratory stresses, even in the case of excitations composed of multiple harmonics.

scholarly journals Multiple Hysteresis Jump Resonance in a Class of Forced Nonlinear Circuits and Systems

2020 ◽  
Vol 30 (15) ◽  
pp. 2050258
Author(s):  
Maide Bucolo ◽  
Arturo Buscarino ◽  
Luigi Fortuna ◽  
Mattia Frasca
Keyword(s):  
Frequency Response ◽  
Design Strategy ◽  
Nonlinear Circuits ◽  
Resonance Phenomenon ◽  
New Class ◽  
Resonance Behavior ◽  
Type Of Behavior

In this paper, a new class of systems with nonclassical jump resonance behavior is presented. Although jump resonance has been widely studied in the literature, this contribution refers to systems presenting a multiple hysteresis jump resonance phenomenon, meaning that the frequency response of the system presents more hysteresis windows nested within the same range of frequency. The analytical conditions for observing this type of behavior are derived and a design strategy to obtain multiple hysteresis jump resonance in circuits and systems presented.

Design of a turning cutting tool with large length–diameter ratio based on three-element type vibration absorber

2020 ◽  
Vol 234 (6-7) ◽  
pp. 1032-1043
Author(s):  
Yiqing Yang ◽  
Haoyang Gao ◽  
Wenshuo Ma ◽  
Qiang Liu
Keyword(s):  
Frequency Response ◽  
Cutting Tool ◽  
Vibration Suppression ◽  
Diameter Ratio ◽  
Vibration Absorber ◽  
Vibration Absorbers ◽  
Target Mode ◽  
Large Length ◽  
Element Type ◽  
Structural Parts

The vibration absorber has been effective in vibration control. From the demand of manufacturing structural parts with a deep hole, the design of a turning cutting tool with large length–diameter ratio is presented. An analytical approach of acquiring frequency response of primary structure equipped with typical single-degree-of-freedom vibration absorbers is formulated, and background modes are incorporated with the purpose of achieving an accurate tuning of vibration absorber. Specifically, the three-element type is investigated as the damping element of the vibration absorber embedded in the cutting tool contributes to the stiffness, although it demonstrates medium performance of vibration suppression according to non-dimensional analysis. The experimentally tuned frequency response function of the turning cutting tool with three-element vibration absorber achieves 87.1% reduction on the amplitude of the target mode. Finally, several configurations of internal turning operations are carried out to validate the design of the vibration absorber.

In Search of Suitable Control Methods for Semi-Active Tuned Vibration Absorbers

2004 ◽  
Vol 10 (2) ◽  
pp. 163-174 ◽  
Author(s):  
Jeong-Hoi Koo ◽  
Mehdi Ahmadian ◽  
Mehdi Setareh ◽  
Thomas Murray
Keyword(s):  
Control Method ◽  
Optimization Techniques ◽  
Structural Vibration ◽  
Design Parameters ◽  
Vibration Absorbers ◽  
Baseline Model ◽  
Control Policies ◽  
Tuned Vibration Absorbers ◽  
Active Peak ◽  
Displacement Based

The main purpose of this study is to identify a suitable control method for semi-active tuned vibration absorbers (TVAs) in structural vibration applications. Four control policies are considered. The semi-active control schemes include the following: velocity-based, on-off groundhook control (on-off VBG); velocity-based, continuous groundhook control (continuous VBG); displacement-based, on-off groundhook control (on-off DBG); and displacement-based, continuous groundhook control (continuous DBG). A force-excited model that can be representative of many structural systems is adapted as the baseline model for our analysis. Each of the control policies is applied to the baseline model coupled with a TVA. In order to equally evaluate the control policies, the TVA parameters are optimized according to each policy using numerical optimization techniques. The optimal design parameters are obtained based on minimization of peak transmissibility. The performances of each of the optimized cases are then compared along with the equivalent passive model using the peak transmissibility criteria. The results indicate that all of the semi-active peak transmissibilities are lower than those of the passive, implying that the semi-active TVAs are more effective in reducing vibration levels. The results further indicate that on-off DBG performs the best among the considered control polices.

Semi-empirical model for a hydraulic servo-solenoid valve

2002 ◽  
Vol 216 (3) ◽  
pp. 237-248 ◽  
Author(s):  
J A Ferreira ◽  
F Gomes de Almeida ◽  
M R Quintas
Keyword(s):  
Frequency Response ◽  
High Performance ◽  
Closed Loop ◽  
Optimization Techniques ◽  
Order System ◽  
Model Parameters ◽  
Empirical Modelling ◽  
Non Linear ◽  
Spool Valves ◽  
Semi Empirical

High-performance proportional valves, also called servo-solenoid valves, can be used today in closed-loop applications that previously were only possible with servo-valves. The valve spool motion is controlled in a closed loop with a dedicated hardware controller that enhances the valve frequency response and minimizes some non-linear effects. Owing to their lower cost and maintenance requirements as well as increasing performance they can compete with servo-valves in a large number of applications. This paper describes a new semi-empirical modelling approach for hydraulic proportional spool valves to be used in hardware-in-the-loop simulation experiments. The developed models use either data sheet or experimental values to fit the model parameters in order to reproduce both static (pressure gain, leakage flowrate and flow gain) and dynamic (frequency response) valve characteristics. Valve behaviour is divided into two parts: the static behaviour and the dynamic behaviour. A parameter decoupled model, with a variable equation structure, and a flexible model, with a fixed equation structure, are proposed for the static part. Spool dynamics are modelled by a non-linear second-order system, with limited velocity and acceleration, the parameters being adjusted using optimization techniques.

scholarly journals A Design Strategy Based on Topology Optimization Techniques for an Additive Manufactured High Performance Engine Piston

2017 ◽  
Vol 11 ◽  
pp. 641-649 ◽  
Author(s):  
Saverio Giulio Barbieri ◽  
Matteo Giacopini ◽  
Valerio Mangeruga ◽  
Sara Mantovani
Keyword(s):  
Topology Optimization ◽  
High Performance ◽  
Design Strategy ◽  
Optimization Techniques ◽  
Engine Piston

Dynamic Response Characteristics of a Nonviscously Damped Oscillator

2008 ◽  
Vol 75 (1) ◽  
Author(s):  
S. Adhikari
Keyword(s):  
Dynamic Response ◽  
Frequency Response ◽  
Response Function ◽  
Frequency Response Function ◽  
Past History ◽  
Maximum Amplitude ◽  
Damping Factor ◽  
Classical Dynamic ◽  
Damped Oscillators ◽  
Damped Oscillator

The characteristics of the frequency response function of a nonviscously damped linear oscillator are considered in this paper. It is assumed that the nonviscous damping force depends on the past history of velocity via a convolution integral over an exponentially decaying kernel function. The classical dynamic response properties, known for viscously damped oscillators, have been generalized to such nonviscously damped oscillators. The following questions of fundamental interest have been addressed: (a) Under what conditions can the amplitude of the frequency response function reach a maximum value?, (b) At what frequency will it occur?, and (c) What will be the value of the maximum amplitude of the frequency response function? Introducing two nondimensional factors, namely, the viscous damping factor and the nonviscous damping factor, we have provided exact answers to these questions. Wherever possible, attempts have been made to relate the new results with equivalent classical results for a viscously damped oscillator. It is shown that the classical concepts based on viscously damped systems can be extended to a nonviscously damped system only under certain conditions.

Computer-Aided Design of Compact Helical Gear Sets

1989 ◽  
Vol 111 (2) ◽  
pp. 285-289 ◽  
Author(s):  
C. S. Jog ◽  
S. S. Pande
Keyword(s):  
Computer Aided Design ◽  
Design Strategy ◽  
Helix Angle ◽  
Helical Gear ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Gear Design ◽  
Computer Aided ◽  
Bending Stresses ◽  
Aided Design

This paper presents the design strategy for the Computer-Aided Design (CAD) of compact helical gear sets. Using optimization techniques, fundamental gear design parameters such as the number of teeth on the pinion, helix angle, and diametral pitch (or module) are selected subject to constraints on bending stresses, contact stresses, and involute interference limits for both standard and nonstandard gearing. The CAD procedure is illustrated with the help of a design example.

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