scholarly journals Dynamical Analysis Applied to Passive Control of Vibrations in a Structural Model Incorporating SMA-SE Coil Springs

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Yuri J. O. Moraes ◽  
Antonio A. Silva ◽  
Marcelo C. Rodrigues ◽  
Antonio G. B. de Lima ◽  
Rômulo P. B. dos Reis ◽  
...  
Keyword(s):  
Smart Materials ◽  
Passive Control ◽  
Structural Model ◽  
Physical World ◽  
Forced Vibrations ◽  
Dynamical Analysis ◽  
Modal Shape ◽  
Irreversible Damage ◽  
Second Mode ◽  
Structure Configuration

Mechanical vibrations are severe phenomena of the physical world. These oscillations may become undesirable and may cause temporary and even irreversible damage to the system. There are several techniques to minimizing these vibration effects ranging from passive methods to the use of controllers with smart materials. In this sense, this study aims to analyze a passive vibration control system installed in a structure that simulates two-floor buildings. This system based on the incorporation of one SMA-SE (Superelastic Shape Memory Alloys) coil springs configuration for energy dissipation and the addition of damping. Modal analysis was performed using analytical, numerical, and experimental methods. In an experimental basis, response amplitudes were analyzed for free and forced vibrations in different configurations. As compared with the structure configuration with steel spring, the forced vibrations FRF (Frequency Response Function) analysis showed a reduction in displacement transmissibility of up to 51% for the first modal shape and 73% for the second mode in the SMA-SE coil spring configuration. As for damping, there was a considerable increase in the order of 59% in the first mode and 119% in the second, for the SMA-SE springs configuration.

Control of Full-Size Frame Structures via Optimum Tuned Mass Dampers

2021 ◽  
Vol 10 (1) ◽  
pp. 47-61
Author(s):  
Apaer Mubuli ◽  
Sinan Melih Nigdeli ◽  
Gebrail Bekdaş
Keyword(s):  
Control Systems ◽  
Structural Control ◽  
Passive Control ◽  
Structural Model ◽  
Frame Structures ◽  
Tuned Mass Dampers ◽  
Element Analysis ◽  
Quarter Century ◽  
Full Size ◽  
Stiffness Properties

Structural control techniques are widely used to reduce the maximum values of the vibrations caused by strong earthquakes and winds and to rapidly dampen them. Among them, passive control systems have been used effectively to protect structural and non-structural elements from the destructive effects of earthquakes in the past quarter-century. Tuned mass dampers (TMD) that are part of passive control systems have been widely used in civil structures with their alternative benefits. In this study, the optimal adjustment of the parameters of a passive TMD placed on the top floor of the 10-story symmetrical structure was performed by a metaheuristic method called Jaya algorithm. The structural model was modeled in the SAP2000 finite element analysis software to obtain mass and stiffness properties. The results of the numerical analysis showed that the optimization of the TMD parameters is highly effective in reducing the total shear forces of the base of the full-size frame structures and reducing displacement in the event of seismic loads.

Control of Sound Radiation of an Active Constrained Layer Damping Plate/Cavity System Using the Structural Intensity Approach

2002 ◽  
Vol 8 (6) ◽  
pp. 903-918 ◽  
Author(s):  
Mohamed S. Azzouz ◽  
J. Ro
Keyword(s):  
Smart Materials ◽  
Passive Control ◽  
Sound Radiation ◽  
Constrained Layer Damping ◽  
Acoustic Cavity ◽  
Structural Intensity ◽  
Vibrating Plates ◽  
Active Constrained Layer Damping ◽  
Cavity System ◽  
Active Constrained Layer

Considerable attention has been devoted to actively and passively controlling the sound radiation from vibrating plates into closed cavities. With the advent of smart materials, extensive effort has been exerted to control the vibration and sound radiation from flexible plates using smart sensors/actuators. The Active Constrained Layer Damping (ACLD) treatment has been used successfully for controlling the vibration of various flexible structures. The treatment provides an effective means for augmenting the simplicity and reliability of passive damping with the low weight and high efficiency of active controls to attain high damping characteristics over broad frequency bands. This study investigates a numerically simulated example consisting of an ACLD treated plate/acoustic cavity system excited by a point harmonic force. In this study, an ACLD treated plate/acoustic cavity coupled finite element model is utilized to calculate the structural intensity and sound pressure radiated by the vibrating plates. In the passive control, the optimum placement of ACLD patches is determined by the structural intensity of ACLD treated plates and compared to the results obtained by using the strain energy approach. The influence on the structural intensity of the plate due to the damping treatment is investigated.

scholarly journals Dynamic experiences generated by sensory features through smart material driven design

2018 ◽  
pp. 48-59
Author(s):  
Marta González-Colominas
Keyword(s):  
Case Studies ◽  
Smart Materials ◽  
Physical World ◽  
Smart Material ◽  
Materials Development ◽  
Sensory Features ◽  
Sensory Modalities ◽  
Sensory Interactions ◽  
Sensory Map ◽  
External Stimuli

Materials can be considered the interface of a product as they mediate between user, environment and object (Karana, Pedgley and Rognoli 2014). They characterize the physical world and generate a continuous flow of sensory interactions. In this age of mass production, engineers and designers are in a unique position to use the opportunities presented by materials development and apply them in creative ways to trigger meaningful user experiences. Dynamism is considered a very promising material experience in terms of creating meaningful interactions, and, consequently, user attachment to a product (Rognoli, Ferrara and Arquilla 2016). Dynamic products are those that show sensory features that change over time in a proactive and reversible way, activating one or more user’s sensory modalities and aiming at enhancing the user’s experience (Colombo 2016). Smart materials could be considered the most suitable candidates to provide dynamic experiences. They react to external stimuli, such as pressure, temperature or the electric field, changing properties such as shape or colour. They are capable of both sensing and responding to the environment, as well as exerting active control of their responses (Addington and Schodek 2004). Compared to understanding traditional materials, smart materials involve additional technical complexity. The aim of this paper is to share how the Material Driven Design (MDD) method (Karana et al. 2015) has been applied and to analyse a set of 10 projects, grouped into 5 case studies, developed by students from ELISAVA over the last 3 years to improve ways to implement the method. We have analysed the case studies in terms of the changes observed in the sensory features, using a sensory map proposed by Sara Colombo (Colombo 2016). By comparing different projects, the paper shows how the sensorial aspects are invoked by different smart material properties. The 5 case studies have integrated the smart materials into functional prototypes for different application sectors, such as healthcare, energy harvesting or fashion. We have found that only three sensory modalities (sound, sight and touch) were involved in the user experience, with sight being the most predominant sensory perception. This study aims to serve as a springboard for other scholars interested in designing dynamic products with smart materials.

Design method of tuned mass damper by LMI based robust control theory for seismic excitation

2022 ◽  
pp. 1-47
Author(s):  
Kou Miyamoto ◽  
Satoshi Nakano ◽  
Jinhua She ◽  
Daiki Sato ◽  
Yinli Chen ◽  
...  
Keyword(s):  
Robust Control ◽  
Control Theory ◽  
Passive Control ◽  
Structural Model ◽  
Design Method ◽  
Tuned Mass Damper ◽  
Structural Vibration ◽  
Linear Matrix ◽  
Mass Damper ◽  
Robust Control Theory

Abstract This paper presents a new design method based on a robust-control strategy in the form of a linear matrix inequality (LMI) approach for a passive tuned mass damper (TMD), which is one of the common passive-control devices for structural vibration control. To apply the robust control theory, we first present an equivalent expression that describes a passive TMD as an active TMD. Then, some LMI-based condition is derived that not only guarantees robust stability but also allows us to adjust the robust H¥ performance. In particular, this paper considers the transfer function from a seismic-wave input to structural responses. Unlike other methods, this method formulates the problem to be a convex optimization problem that ensures a global optimal solution and considers uncertainties of mass, damping, and stiffness of a structure for designing a TMD. Numerical example uses both a single-degree-of-freedom (SDOF) and 10DOF models, and seismic waves. The simulation results demonstrated that the TMD that is designed by the presented method has good control performance even if the structural model includes uncertainties, which are the modeling errors.

Seismic Evaluation of Base Isolated System Equipped with Shape Memory Alloys

2013 ◽  
Vol 831 ◽  
pp. 110-114
Author(s):  
S. Alvandi ◽  
M. Ghassemieh
Keyword(s):  
Shape Memory Alloys ◽  
Shape Memory ◽  
Seismic Isolation ◽  
Passive Control ◽  
Structural Model ◽  
Base Isolation ◽  
Base Shear ◽  
Seismic Evaluation ◽  
Isolation System ◽  
Base Isolation System

Seismic isolation system is an example of passive control system that effectively improves the performance of structures. This research discusses the seismic performance of a elastomeric base isolation system which provide the combined features of vertical load support, horizontal flexibility and energy absorbing capacity, utilizing shape memory alloys that provides re-centering force and additional damping in the system. Also this paper compares the effect of such alloys with memory effect and/or superelasticity (with pre-straining) in base isolated structure. To provide such comparison, a nonlinear structural model has been developed on some benchmark control problems and some health monitoring evaluation criterias are used. The smart base isolation utilizes the different responses of shape memory alloys at several levels of strain to control the displacements of the rubber bearing and base shear at excitation level. Furthermore the proposed based isolation systems has enhanced performance in terms of response reduction and re-centering capacity.

Dynamical analysis and passive control of a new 4D chaotic system with multiple attractors

2018 ◽  
Vol 32 (22) ◽  
pp. 1850260 ◽  
Author(s):  
Long Wang ◽  
Mei Ding
Keyword(s):  
Chaotic System ◽  
Passive Control ◽  
Strange Attractors ◽  
Dynamical Analysis ◽  
Bifurcation Diagrams ◽  
Multiple Attractors ◽  
Initial Values ◽  
System A ◽  
Periodic Attractors ◽  
Theoretical Results

This paper constructs a new 4D chaotic system from the Sprott B system. The system is dissipative, chaotic with two saddle foci. The bifurcation diagrams verify that the system exists multiple attractors with different initial values, including two strange attractors, two periodic attractors. Furthermore, we apply the passive control to control the system. A controller is designed for driving the system to the origin. The simulations show our theoretical results visually.

An Investigation of the Electroaeroelastic Behavior of a Locally Resonant Piezoelectric Metastructure

2018 ◽  
Author(s):  
Gabriel B. Schiavon ◽  
Joao H. R. Dainezi ◽  
Carlos De Marqui
Keyword(s):  
Control Systems ◽  
Smart Materials ◽  
Passive Control ◽  
Flexible Substrates ◽  
Aerodynamic Loads ◽  
Unsteady Aerodynamic ◽  
Control Schemes ◽  
Piezoelectric Layers ◽  
Rotary Wings ◽  
Resonant Shunt

The literature of aeroelasticity includes the use of smart materials to modify the aeroelastic behavior of fixed or rotary wings. In some cases, they are employed as actuators in active control systems while in others the use of smart materials in passive control schemes is investigated. In this work a different approach is investigated. The aeroelastic behavior of a locally resonant electromechanical metastructure made from flexible substrates with piezoelectric layers connected to resonant shunt circuits is investigated. An electromechanically coupled finite element plate model is employed for predicting the electroelasatic behavior of the wing. The unsteady aerodynamic loads are obtained from the doublet lattice model. By combining the structural and aerodynamic models, the aeroelastic behavior of the metastructure over a range of airflow speeds is studied.

scholarly journals Experimental results for active control of multimodal vibrations by optimally placed piezoelectric actuators

2018 ◽  
Vol 211 ◽  
pp. 20001 ◽  
Author(s):  
Andrea Rossi ◽  
Fabio Botta ◽  
Roberto Maiozzi ◽  
Andrea Scorza ◽  
Salvatore Andrea Sciuto
Keyword(s):  
Cantilever Beam ◽  
Smart Materials ◽  
Potential Distribution ◽  
Passive Control ◽  
Piezoelectric Actuators ◽  
Vibration Damping ◽  
Active Systems ◽  
Electrodynamic Shaker ◽  
And Performance ◽  
And Control

Vibration damping is an effective strategy to enhance the life-cycle and performance of mechanical components. In this regard passive control systems involve lower costs and are easier to implement but their bandwidth is limited, whereas active systems provide larger bandwidth and higher adaptability to dynamic loads but higher costs and complexity are required. The recent advances in smart materials promoted the development of smart structures suitable for vibration damping and control. Between them the piezoelectric systems seem to be the most promising, however their efficiency relies on their placement. In a previous work the authors proposed and validated an analytical method to detect the optimal location of piezoelectric plates to control the multi-modal vibrations of a cantilever beam. Recent findings show that, if all actuators are activated simultaneously, the optimization problem can be traced back to the determination of the optimal potential distribution on all the piezoelectric actuators. In this paper the above method is taken into account and applied to a cantilever beam with 13 pairs of surface mounted PZT plates under the excitation provided by an electrodynamic shaker. The experimental damping of two flexural modes combinations has been performed by means of a special-purpose workbench and the assessment of the damping efficiency has been measured by means of a micro I.C.P. accelerometer. The results showed that the multimode vibrations of the cantilever beam can be efficiently damped if the potential distribution on all the PZT plates is optimized.

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