An Active-Passive Piezoelectric Vibration Absorber for Structural Control Under Harmonic Excitations With Time-Varying Frequency

2000 ◽  
Author(s):  
Ronald A. Morgan ◽  
K. W. Wang
Keyword(s):  
Active Control ◽  
Structural Control ◽  
High Performance ◽  
Piezoelectric Materials ◽  
Negative Resistance ◽  
Electrical Circuit ◽  
Superior Performance ◽  
Electrical Networks ◽  
Harmonic Excitations ◽  
Time Varying Frequency

Abstract It has been shown that piezoelectric materials can be used as passive electromechanical vibration absorbers when shunted by electrical networks. Semi-active piezoelectric absorbers have also been proposed for suppressing harmonic excitations with varying frequency. However, these semi-active devices have limitations that restrict their applications. The design presented here is a high performance active-passive alternative to semi-active absorbers that uses a combination of a passive electrical circuit and active control actions. The active control consists of three parts: an adaptive inductor tuning action, a negative resistance action, and a coupling enhancement action. A formulation for the optimal tuning of the piezoelectric absorber inductance on a multiple degree of freedom (MDOF) structure is derived. The effectiveness of the proposed system is demonstrated experimentally on a system under a variable frequency excitation. Extensive parameter studies are also carried out to show that the proposed design offers superior performance and efficiency compared to other state-of-the-art control methods.

An Active-Passive Piezoelectric Absorber for Structural Vibration Control Under Harmonic Excitations With Time-Varying Frequency, Part 1: Algorithm Development and Analysis

2001 ◽  
Vol 124 (1) ◽  
pp. 77-83 ◽  
Author(s):  
R. A. Morgan ◽  
K. W. Wang
Keyword(s):  
Active Control ◽  
High Performance ◽  
Piezoelectric Materials ◽  
Negative Resistance ◽  
Electrical Circuit ◽  
Structural Vibration ◽  
Experimental Investigations ◽  
Electrical Networks ◽  
Practical Applications ◽  
Harmonic Excitations

It has been shown that piezoelectric materials can be used as passive electromechanical vibration absorbers by shunting them with electrical networks. Semi-active piezoelectric absorbers have also been proposed for suppressing harmonic excitations with varying frequency. However, these semi-active devices have limitations that restrict their practical applications. The approach presented here is a high performance active-passive alternative to semi-active absorbers. By utilizing a combination of a passive electrical circuit and active control actions, the system is synthesized for adaptive variable frequency narrowband disturbance rejection. The active control consists of three parts: an inductor tuning action, a negative resistance action, and a coupling enhancement action. In the current paper (Part 1), the control algorithm is developed and analyzed. Part 2 of the paper contains experimental investigations and parametric studies of the new absorber design.

An Active-Passive Piezoelectric Absorber for Structural Vibration Control Under Harmonic Excitations With Time-Varying Frequency, Part 2: Experimental Validation and Parametric Study

2001 ◽  
Vol 124 (1) ◽  
pp. 84-89 ◽  
Author(s):  
R. A. Morgan ◽  
K. W. Wang
Keyword(s):  
High Performance ◽  
Superior Performance ◽  
Structural Vibration ◽  
Design Parameters ◽  
Experimental Investigations ◽  
Attractive Alternative ◽  
Structural Vibration Control ◽  
Harmonic Excitations ◽  
Time Varying Frequency ◽  
Parametric Studies

In Part 1 of the paper, a new high-performance active-passive hybrid piezoelectric absorber concept was presented. This design is an attractive alternative to semi-active absorbers for the purpose of suppressing harmonic excitations with variable frequency. In this paper (Part 2), the effectiveness of the new absorber design is first demonstrated through experimental investigations. Parametric studies are then carried out to illustrate how the performance of the new design is affected by the design parameters and excitation characteristics. In these studies, two state-of-the-art control methods are used as baselines for comparison with the new absorber design, and it is shown that the proposed design offers superior performance and efficiency compared to these methods.

scholarly journals Particle Size Effect of Lanthanum-Modified Bismuth Titanate Ceramics on Ferroelectric Effect for Energy Harvesting

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Sangmo Kim ◽  
Thi My Huyen Nguyen ◽  
Rui He ◽  
Chung Wung Bark
Keyword(s):  
Particle Size ◽  
Energy Harvesting ◽  
High Speed ◽  
High Performance ◽  
Bismuth Titanate ◽  
Vinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Renewable Energy Sources ◽  
Particle Size Effect ◽  
Ferroelectric Materials

AbstractPiezoelectric nanogenerators (PNGs) have been studied as renewable energy sources. PNGs consisting of organic piezoelectric materials such as poly(vinylidene fluoride) (PVDF) containing oxide complex powder have attracted much attention for their stretchable and high-performance energy conversion. In this study, we prepared a PNG combined with PVDF and lanthanum-modified bismuth titanate (Bi4−XLaXTi3O12, BLT) ceramics as representative ferroelectric materials. The inserted BLT powder was treated by high-speed ball milling and its particle size reduced to the nanoscale. We also investigated the effect of particle size on the energy-harvesting performance of PNG without polling. As a result, nano-sized powder has a much larger surface area than micro-sized powder and is uniformly distributed inside the PNG. Moreover, nano-sized powder-mixed PNG generated higher power energy (> 4 times) than the PNG inserted micro-sized powder.

Structural Control Considering Time Delay Effect

1985 ◽  
Vol 9 (4) ◽  
pp. 224-227 ◽  
Author(s):  
Mohamed Abdel-Rohman
Keyword(s):  
Time Delay ◽  
Active Control ◽  
Theoretical Consideration ◽  
Structural Control ◽  
Control Mechanism ◽  
Structural Response ◽  
Delay Effect ◽  
Numerical Example ◽  
Control Forces ◽  
Time Delay Effect

The time delay between measuring the structural response, and applying the designed active control forces may affect the controlled response of the structure if not taken into consideration. In this paper it is shown how to design the control forces to compensate for the delay effect. It is also shown that the time delay effect can be used as a criterion to judge the effectiveness of the proposed control mechanism. As an illustration of the theoretical consideration, a numerical example in which a tall building is controlled by means of active tendons is presented.

The Semi-Active Control Considering Structure-Basement-Pile-Soil Interaction

2010 ◽  
Vol 163-167 ◽  
pp. 2780-2786
Author(s):  
Yan Tao Li ◽  
Zhan Xue Zhou
Keyword(s):  
Active Control ◽  
Structural Control ◽  
Soil Structure ◽  
Tall Buildings ◽  
Interaction System ◽  
Subdomain Method ◽  
Infinite Element Method ◽  
Fixed End ◽  
Instantaneous Optimal Control ◽  
The Impact

The interaction system which includes pi1e-supported tall buildings with multistoried basements and the adjacent medium of soil subject to the impact of earthquake is formulated in terms of the spline subdomain method,semi-analytical infinite element method and the bend-shear model of beam element,respectively.Taking advantage of the instantaneous optimal control algorithm, structure-basements-piles-soil interaction effect on the semi-active control is considered. It is shown that the results of structural control have obvious difference between the interaction system and the fixed-end system.The response of the former may be less about 10 percent than the latter in the paper.The dissipative capability of the structure self may be ignored largely if the interaction isn’t considered.When designing the system of the semi-active control, especially for some tall buildings,soil-structure interaction should be taken into consideration.

Low ECD High Performance Invert Emulsion Drilling Fluids: Lab Development and Field Deployment

2021 ◽  
Author(s):  
Vikrant Wagle ◽  
Abdullah Yami ◽  
Michael Onoriode ◽  
Jacques Butcher ◽  
Nivika Gupta
Keyword(s):  
High Performance ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Field Performance ◽  
Superior Performance ◽  
Core Material ◽  
Drilling Fluids ◽  
Invert Emulsion ◽  
Field Deployment ◽  
Permeability Studies

Abstract The present paper describes the results of the formulation of an acid-soluble low ECD organoclay-free invert emulsion drilling fluid formulated with acid soluble manganese tetroxide and a specially designed bridging package. The paper also presents a short summary of field applications to date. The novel, non-damaging fluid has superior rheology resulting in lower ECD, excellent suspension properties for effective hole cleaning and barite-sag resistance while also reducing the risk of stuck pipe in high over balance applications. 95pcf high performance invert emulsion fluid (HPIEF) was formulated using an engineered bridging package comprising of acid-soluble bridging agents and an acid-soluble weighting agent viz. manganese tetroxide. The paper describes the filtration and rheological properties of the HPIEF after hot rolling at 300oF. Different tests such as contamination testing, sag-factor analysis, high temperature-high pressure rheology measurements and filter-cake breaking studies at 300oF were performed on the HPIEF. The 95pcf fluid was also subjected to particle plugging experiments to determine the invasion characteristics and the non-damaging nature of the fluids. The 95pcf HPIEF exhibited optimal filtration properties at high overbalance conditions. The low PV values and rheological profile support low ECDs while drilling. The static aging tests performed on the 95pcf HPIEF resulted in a sag factor of less than 0.53, qualifying the inherent stability for expected downhole conditions. The HPIEF demonstrated resilience to contamination testing with negligible change in properties. Filter-cake breaking experiments performed using a specially designed breaker fluid system gave high filter-cake breaking efficiency. Return permeability studies were performed with the HPIEF against synthetic core material, results of which confirmed the non-damaging design of the fluid. The paper thus demonstrates the superior performance of the HPIEF in achieving the desired lab and field performance.

A New X-Actuator Design for Controlling Wing Bending and Twisting Modes

1999 ◽  
Author(s):  
R. Ye ◽  
J. H. Ding ◽  
H. S. Tzou
Keyword(s):  
Structural Control ◽  
High Performance ◽  
Fe Method ◽  
Aerodynamic Efficiency ◽  
Aircraft Wings ◽  
Helicopter Blades ◽  
Active Structural Control ◽  
Trailing Edges ◽  
Parallel Configuration ◽  
Actuator Design

Abstract Recent development of smart structures and structronic systems has demonstrated the technology in many engineering applications. Active structural control of aircraft wings or helicopter blades (e.g., shapes, flaps, leading and/or trailing edges) can significantly enhance the aerodynamic efficiency and flight maneuverability of high-performance airplanes and helicopters. This paper in to evaluate the dual bending and torsion vibration control effects of an X-actuator configuration reconfigured from a parallel configuration. Finite element (FE) formation of a new FE using the layerwise constant shear angle theory is reviewed and the derived governing equations are discussed. Bending and torsion control effects of plates are studied using the FE method and also demonstrated via laboratory experiments. FE and experimental results both suggest the X-actuator is effective to both bending and torsion control of plates.

Numerical study of active control by piezoelectric materials for fluid–structure interaction problems

2018 ◽  
Vol 435 ◽  
pp. 23-35 ◽  
Author(s):  
Shigeki Kaneko ◽  
Giwon Hong ◽  
Naoto Mitsume ◽  
Tomonori Yamada ◽  
Shinobu Yoshimura
Keyword(s):  
Active Control ◽  
Numerical Study ◽  
Piezoelectric Materials ◽  
Fluid Structure Interaction ◽  
Fluid Structure ◽  
Structure Interaction

scholarly journals Atomic Modulation of 3D Conductive Frameworks Boost Performance of MnO2 for Coaxial Fiber-Shaped Supercapacitors

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Xiaona Wang ◽  
Zhenyu Zhou ◽  
Zhijian Sun ◽  
Jinho Hah ◽  
Yagang Yao ◽  
...  
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Superior Performance ◽  
High Mass ◽  
Mass Loading ◽  
Energy Storage Devices ◽  
Free Standing ◽  
Cell Potential

Abstract Coaxial fiber-shaped supercapacitors are a promising class of energy storage devices requiring high performance for flexible and miniature electronic devices. Yet, they are still struggling from inferior energy density, which comes from the limited choices in materials and structure used. Here, Zn-doped CuO nanowires were designed as 3D framework for aligned distributing high mass loading of MnO2 nanosheets. Zn could be introduced into the CuO crystal lattice to tune the covalency character and thus improve charge transport. The Zn–CuO@MnO2 as positive electrode obtained superior performance without sacrificing its areal and gravimetric capacitances with the increasing of mass loading of MnO2 due to 3D Zn–CuO framework enabling efficient electron transport. A novel category of free-standing asymmetric coaxial fiber-shaped supercapacitor based on Zn0.11CuO@MnO2 core electrode possesses superior specific capacitance and enhanced cell potential window. This asymmetric coaxial structure provides superior performance including higher capacity and better stability under deformation because of sufficient contact between the electrodes and electrolyte. Based on these advantages, the as-prepared asymmetric coaxial fiber-shaped supercapacitor exhibits a high specific capacitance of 296.6 mF cm−2 and energy density of 133.47 μWh cm−2. In addition, its capacitance retention reaches 76.57% after bending 10,000 times, which demonstrates as-prepared device’s excellent flexibility and long-term cycling stability.

Performance on an Adaptive Automated Team Tracking Task with Human and Computer Teammates

1997 ◽  
Vol 41 (1) ◽  
pp. 551-555 ◽  
Author(s):  
Kristin Krahl ◽  
Mark W. Scerbo
Keyword(s):  
Adaptive Systems ◽  
High Performance ◽  
Vertical Axis ◽  
Tracking Task ◽  
Superior Performance ◽  
Performance Skills ◽  
Group Assignment ◽  
Pursuit Tracking ◽  
Human Participants ◽  
High Level

The present study examined team performance on an adaptive pursuit tracking task with human-human and human-computer teams. The participants were randomly assigned to one of three team conditions where their partner was either a computer novice, computer expert, or human. Participants began the experiment with control over either the horizontal or vertical axis, but had the option of taking control of their teammate's axis if they achieved superior performance on the previous trial. A control condition was also run where a single participant controlled both axes. Performance was assessed by RMSE scores over 100 trials. The results showed that performance along the horizontal axis improved over the session regardless of the experimental condition, but the degree of improvement was dependent upon group assignment. Individuals working alone or paired with an expert computer maintained a high level of performance throughout the experiment. Those paired with a computer-novice or another human performed poorly initially, but eventually reached the level of those in the other conditions. The results showed that team training can be as effective as individual training, but that the quality of training is moderated by the skill level of one's teammate. Moreover, these findings suggest that task partitioning of high performance skills between a human and a computer is not only possible but may be considered a viable option in the design of adaptive systems.

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