Transition of Neural Signals on Cylindrical Shells With Various Curvatures

2005 ◽  
Author(s):  
J. G. DeHaven ◽  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Cylindrical Shell ◽  
High Performance ◽  
Cylindrical Shells ◽  
Free Vibration Analysis ◽  
Dynamic Responses ◽  
Neural Signals ◽  
Natural Modes ◽  
Shell Panel ◽  
Membrane Strain ◽  
And Control

Sensing and control are essential to achieving the high performance and high precision of modern aerospace structures and systems. Typical off-the-shelf sensors placed at discrete locations usually add additional weights and thus often influence dynamic responses of precision systems. Unlike the conventional discrete add-on sensors, thin lightweight piezoelectric layers can be spatially spread and distributed over the surfaces of precision structures. The purpose of this study is to investigate microscopic neural signal generations from infinitesimal piezoelectric neurons over a cylindrical shell panel of various curvature angles and to determine dominating signal components resulting from longitudinal or circumferential membrane strains or longitudinal or circumferential bending strains. Dynamic equations of cylindrical shells are defined first, followed by free-vibration analysis. Then, mode shape functions and modal spatial strain distributions are used to determine the signal generation of distributed neuron sensors laminated on a linear cylindrical shell panel. The microscopic signal generations of infinitesimal piezoelectric sensors or neurons are investigated for three different curvature angles, i.e., β* = 30°, 90°, and 150°, of a simply-supported cylindrical shell panel. Evaluating these three cases suggests that as the curvature increases from 0° to 360°, the neural signals from the membrane strain dominate for lower natural modes before the neural signals from the bending strain become dominating as the mode increases.

Control of Cylindrical Shell Panels With Input Shaping and Phase Shift of Shape Memory Ring Segments

2005 ◽  
Author(s):  
J. G. DeHaven ◽  
H. S. Tzou
Keyword(s):  
Cylindrical Shell ◽  
Shape Memory ◽  
Free Vibration Analysis ◽  
Harmonic Excitation ◽  
Optimal Placement ◽  
Elastic Cylindrical Shell ◽  
Control Force ◽  
Control Effect ◽  
Longitudinal Modes ◽  
Shell Panel

The purpose of this study is to investigate the control effect from shape memory alloy (SMA) ring segments placed at the desired positions along the length of a cylindrical shell panel. Equations of motion for an elastic cylindrical shell panel are defined first and then used with the assumed mode shape functions for the appropriate boundary conditions in a free vibration analysis. The results from this are used with the generic shell sensing equation to determine the spatial strain distribution. From this, optimal placement of ring segments for each given mnth mode is determined. Through use of the modal expansion method, the open-loop control force induced by the SMA ring segments applied to a cylindrical shell panel is determined next. This evaluation shows that only the odd modes in the circumferential direction can be controlled. Longitudinal modes are controlled via placing a varying number, depending on the mode, of ring segments along the length of the cylindrical shell panel. To predict control effects of the SMA ring segments, the modal participation factor response is determined for an external harmonic excitation applied to the shell along with SMA control force induced to eliminate the unwanted effects. The results show that with proper choice of waveform function for the applied temperature to the SMA ring segments and minor modifications to frequency and phase, the SMA ring segments can control unwanted external vibration.

scholarly journals Development of High-Performance Soft Robotic Fish by Numerical Coupling Analysis

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Wenjing Zhao ◽  
Aiguo Ming ◽  
Makoto Shimojo
Keyword(s):  
High Performance ◽  
Fiber Composite ◽  
Swimming Performance ◽  
Structural Parameters ◽  
Robotic Fish ◽  
Dynamic Responses ◽  
Flexible Structure ◽  
Swimming Velocity ◽  
Coupling Analysis ◽  
And Control

To design a soft robotic fish with high performance by a biomimetic method, we are developing a soft robotic fish using piezoelectric fiber composite (PFC) as a flexible actuator. Compared with the conventional rigid robotic fish, the design and control of a soft robotic fish are difficult due to large deformation of flexible structure and complicated coupling dynamics with fluid. That is why the design and control method of soft robotic fish have not been established and they motivate us to make a further study by considering the interaction between flexible structure and surrounding fluid. In this paper, acoustic fluid-structural coupling analysis is applied to consider the fluid effect and predict the dynamic responses of soft robotic fish in the fluid. Basic governing equations of soft robotic fish in the fluid are firstly described. The numerical coupling analysis is then carried out based on different structural parameters of soft robotic fish. Through the numerical analysis, a new soft robotic fish is finally designed, and experimental evaluation is performed. It is confirmed that the larger swimming velocity and better fish-like swimming performance are obtained from the new soft robotic fish. The new soft robotic fish is developed successfully for high performance.

Precision Microscopic Actuations of Parabolic Cylindrical Shell Reflectors

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou
Keyword(s):  
Cylindrical Shell ◽  
Piezoelectric Actuator ◽  
Cylindrical Shells ◽  
Active Vibration Control ◽  
Modal Control ◽  
Control Force ◽  
Signal Collection ◽  
Shell Panel ◽  
Active Vibration ◽  
Radar Antennas

An open parabolic cylindrical shell panel plays a key role in radial signal collection, reflection, and/or transmission applied to radar antennas, space reflectors, solar collectors, etc. Active vibration control can suppress unexpected fluctuation and maintain its precision surface and operations. This study aims to investigate the distributed active actuation behavior of adaptive open parabolic cylindrical shell panels using piezoelectric actuator patches. Dynamic equations of parabolic cylindrical shells laminated with piezoelectric actuator patches are presented first. Then, the actuator induced modal control force is defined based on a newly derived mode shape function. As the actuator area varies due to the curvature change, the normalized actuation effectiveness (i.e., modal control force per unit actuator area) is further evaluated. When the actuator area shrinks to infinitesimal, the expression of microscopic local modal control force is obtained to predict the spatial microscopic actuation behavior on parabolic cylindrical shells. The total control force and its three components exhibit distinct characteristics with respect to shell geometries, modes, and actuator properties. Analyzes suggest that the control force contributed by the membrane force component dominates the total actuation effect. The bending-contributed component increases with the corresponding mode number, while the membrane-contributed component decreases. Actuation effectiveness of two shell geometries, from shallow to deep, and actuator sizes are evaluated. Analysis of optimal actuator locations reveals that actuators placed at the maximal shell curvature are more effective and maximize the control effects.

Transition of Neural Signals on Adaptive Cylindrical Paraboloidal Shells

Aerospace ◽  
2006 ◽  
Author(s):  
Y. Han ◽  
H. S. Tzou
Keyword(s):  
Communication Systems ◽  
High Performance ◽  
Radial Distance ◽  
Transverse Mode ◽  
Radius Of Curvature ◽  
Neural Signals ◽  
Distributed Sensors ◽  
Shell Panel ◽  
Definition Of ◽  
Paraboloidal Shell

Cylindrical paraboloidal shells are common structures in communication systems, precision opto-mechanical systems and high-precision modern aerospace structures. Sensing is essential to validate the high performance of these modern structures. The purpose of this study is 1) to investigate microscopic neural signal generations from infinitesimal piezoelectric sensors over a cylindrical paraboloidal shell panel with curvature changes and 2) to determine the dominant signal component resulting from longitudinal or circumferential membrane strains and longitudinal or circumferential bending strains. Mathematical models of the cylindrical paraboloidal shells are presented first, followed by definition of the transverse mode shape function. Then, the microscopic signal generations of distributed sensors laminated on a cylindrical paraboloidal shell panel with simply-supported boundary conditions are investigated for three different cases: the ratio of meridian to radial distance of parabola at 1:4 (shallow), 1:1 (baseline) and 2:1 (deep). Analyzing these three cases suggests that as the shell changes from shallow to deep, 1) the circumferential membrane neural signals dominate more lower modes before the circumferential bending signals become dominant for n<m and the longitudinal bending signals become dominant for n>m as the mode increases and 2) the neural signals become localized where the curvature is small. Due to non-constant radius of curvature, these signal transitions on the cylindrical paraboloidal shells are rather unique, which has not been observed in other shells.

Nonlinear Dynamic Analysis and Control of FG Cylindrical Shell Fitted with Piezoelectric Layers

2021 ◽  
pp. 2150083
Author(s):  
Aliakbar Bayat ◽  
Amir Jalali ◽  
Habib Ahmadi
Keyword(s):  
Cylindrical Shell ◽  
Differential Equations ◽  
Vibration Control ◽  
Power Index ◽  
Cylindrical Shells ◽  
Excitation Frequency ◽  
Shear Deformation Theory ◽  
Phase Portraits ◽  
Piezoelectric Layers ◽  
And Control

In this study, the nonlinear vibration control of functionally graded laminated piezoelectric cylindrical shells under simultaneous parametric axial and radial external excitations is presented. The partial differential equations of shells are derived based on Hamilton’s principle, first-order shear deformation theory (FSDT), and nonlinear von Karman relations. The coupled nonlinear ordinary differential equations are obtained by Galerkin’s procedure and solved by the method of static condensation. Two piezoelectric layers are placed on the outer and inner surfaces of the cylindrical shell each as distributed sensor and actuator. Then the constant-gain negative velocity feedback strategy is employed. Regarding the nonlinear equations of motion, for the first time, the vibration analysis and active vibration control of smart FG cylindrical shells under combined parametric and external excitations are analyzed using the multiple scales approach. The effects of various parameters such as power index, external excitation’s amplitude, and control gain on the dynamic behavior of the system are investigated, using bifurcation diagrams, phase portraits, time histories, and Poincare maps. It is shown that quasi-periodic motion is the most common behavior of the system and controller gain and power index have inevitable effects on enhancing the quasi-periodic response of the system. Care should be exerted in selecting the parameters to have the desired response in the broad range of excitation frequency.

Shell Transformations and Distributed Sensing/Control Characteristics

1997 ◽  
Author(s):  
H. S. Taou ◽  
Y. Bao ◽  
V. B. Venkayya ◽  
H. Bahrami
Keyword(s):  
Shallow Shell ◽  
Natural Frequencies ◽  
Rotor Blades ◽  
Distributed Sensing ◽  
Higher Modes ◽  
Control Behavior ◽  
Damping Control ◽  
Natural Modes ◽  
Shell Panel ◽  
And Control

Abstract Adaptive and controllable shapes and geometries of shells are desirable in many engineering applications, such as antenna dishes, rotor blades, airplane wings, nozzles, etc. In this paper, detailed sensing and control behavior of an adaptive shell panel are investigated. The shell panel changes its geometry from an open shallow shell (30°) to a deep cylindrical shell (150°). Natural frequencies, distributed sensing and damping control characteristics associated with the curvature changes are investigated. Mathematical modeling is presented first, followed by solution procedures. Membrane and bending contributions in sensing and control are evaluated. It is observed that natural frequencies of lower natural modes increase and those of higher modes decrease in the process of curvature transformation from 30° to 150°. Analytical solutions suggest that the membrane sensitivity becomes increasingly important when the curvature increases. The damping controllability of lower modes decreases as the shell curvature increases, however, that of higher modes still increases.

scholarly journals Reduction of Polycyclic Aromatic Hydrocarbons (PAHs) in Sesame Oil Using Cellulosic Aerogel

Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 644
Author(s):  
Do-Yeong Kim ◽  
Boram Kim ◽  
Han-Seung Shin
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
High Performance ◽  
Oil Quality ◽  
Acid Value ◽  
Quality Parameters ◽  
Sesame Oil ◽  
Miscanthus Sinensis ◽  
Polycyclic Aromatic ◽  
And Control

The effect of cellulosic aerogel treatments used for adsorption of four polycyclic aromatic hydrocarbons (PAHs)—benzo[a]anthracene, chrysene, benzo[b]fluoranthene, and benzo[a]pyrene [BaP])—generated during the manufacture of sesame oil was evaluated. In this study, eulalia (Miscanthus sinensis var. purpurascens)-based cellulosic aerogel (adsorbent) was prepared and used high performance liquid chromatography with fluorescence detection for determination of PAHs in sesame oil. In addition, changes in the sesame oil quality parameters (acid value, peroxide value, color, and fatty acid composition) following cellulosic aerogel treatment were also evaluated. The four PAHs and their total levels decreased in sesame oil samples roasted under different conditions (p < 0.05) following treatment with cellulosic aerogel. In particular, highly carcinogenic BaP was not detected after treatment with cellulosic aerogel. Moreover, there were no noticeable quality changes in the quality parameters between treated and control samples. It was concluded that eulalia-based cellulosic aerogel proved suitable for the reduction of PAHs from sesame oil and can be used as an eco-friendly adsorbent.

Advanced high-performance processing tools for diagnostics and control in fusion devices

2021 ◽  
Vol 170 ◽  
pp. 112529
Author(s):  
N. Cruz ◽  
A.J.N. Batista ◽  
J.M. Cardoso ◽  
B.B. Carvalho ◽  
P.F. Carvalho ◽  
...  
Keyword(s):  
High Performance ◽  
Diagnostics And Control ◽  
And Control

scholarly journals Detection of Antimicrobial Residues in Poultry Litter: Monitoring a Risk through a Selective and Sensitive HPLC–MS/MS Method

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1399
Author(s):  
Karina Yévenes ◽  
Ekaterina Pokrant ◽  
Lina Trincado ◽  
Lisette Lapierre ◽  
Nicolás Galarce ◽  
...  
Keyword(s):  
High Performance ◽  
Limit Of Detection ◽  
Poultry Litter ◽  
Chromatography Tandem Mass Spectrometry ◽  
Antimicrobial Residues ◽  
Field Samples ◽  
Liquid Chromatography Tandem Mass ◽  
Commercial Poultry ◽  
Agriculture Fertilizer ◽  
And Control

Tetracyclines, sulphonamides, and quinolones are families of antimicrobials (AMs) widely used in the poultry industry and can excrete up to 90% of AMs administrated, which accumulate in poultry litter. Worryingly, poultry litter is widely used as an agriculture fertilizer, contributing to the spread AMs residues in the environment. The aim of this research was to develop a method that could simultaneously identify and quantify three AMs families in poultry litter by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). Samples of AMs free poultry litter were used to validate the method according to 657/2002/EC and VICH GL49. Results indicate that limit of detection (LOD) ranged from 8.95 to 20.86 μg kg−1, while limits of quantitation (LOQ) values were between 26.85 and 62.58 µg kg−1 of tetracycline, 4-epi-tetracycline, oxytetracycline, 4-epi-oxytetracycline, enrofloxacin, ciprofloxacin, flumequine, sulfachloropyridazine, and sulfadiazine. Recoveries obtained ranged from 93 to 108%. The analysis of field samples obtained from seven commercial poultry flocks confirmed the adequacy of the method since it detected means concentrations ranging from 20 to 10,364 μg kg−1. This provides us an accurate and reliable tool to monitor AMs residues in poultry litter and control its use as agricultural fertilizer.

Sign in / Sign up

Export Citation Format

Share Document