Vibration Localization in a Fluid-Loaded Rectangular Plate with Rib Irregularity

2012 ◽  
Vol 226-228 ◽  
pp. 191-194
Author(s):  
Hao Hao Hu ◽  
De Jiang Shang
Keyword(s):  
Coupling Effect ◽  
Coupled System ◽  
Expansion Method ◽  
Heavy Fluid ◽  
Range Interaction ◽  
Modal Expansion ◽  
Vibration Localization ◽  
Modal Expansion Method ◽  
Force Coupling ◽  
Long Range Interaction

This paper studies the vibration localization of fluid-loaded irregularly ribbed plate analytically. The modal expansion method was adopted to solve the multi-coupled system, the ribs were considered as Timoshenko beams attached to the plate. The localization mechanism was investigated by comparing different coupling effect at the plate-beam interface, it was found the ribs space irregularity only localize the modes associated with the shear force coupling. Both the light and heavy fluid loading pressure were concerned by Rayleigh integral , the study showed that obvious vibration localization phenomenon can be achieved by the ribs space irregularity, and the localization effect was weakened by the long range interaction through the heavy fluid, although the response amplitude of the modes decreased obviously. The investigation may be quite significant for vibration confinement and noise control in engineering.

Analytic solutions of the scattering by two multilayered dielectric spheres

1992 ◽  
Vol 70 (9) ◽  
pp. 696-705 ◽  
Author(s):  
A-K. Hamid ◽  
I. R. Ciric ◽  
M. Hamid
Keyword(s):  
Boundary Conditions ◽  
Cross Sections ◽  
Plane Electromagnetic Wave ◽  
Expansion Method ◽  
Analytic Solutions ◽  
Addition Theorem ◽  
Modal Expansion ◽  
Modal Expansion Method ◽  
Dielectric Spheres ◽  
Scattered Fields

The problem of plane electromagnetic wave scattering by two concentrically layered dielectric spheres is investigated analytically using the modal expansion method. Two different solutions to this problem are obtained. In the first solution the boundary conditions are satisfied simultaneously at all spherical interfaces, while in the second solution an iterative approach is used and the boundary conditions are satisfied successively for each iteration. To impose the boundary conditions at the outer surface of the spheres, the translation addition theorem of the spherical vector wave functions is employed to express the scattered fields by one sphere in the coordiante system of the other sphere. Numerical results for the bistatic and back-scattering cross sections are presented graphically for various sphere sizes, layer thicknesses and permittivities, and angles of incidence.

Vibration Control of a Multi-Layer Piezoelectric Cylindrical Shell

1997 ◽  
Author(s):  
Jinhao Qiu ◽  
Junji Tani
Keyword(s):  
Cylindrical Shell ◽  
Feedforward Control ◽  
Equations Of Motion ◽  
Good Control ◽  
Expansion Method ◽  
Piezoelectric Sensor ◽  
State Equation ◽  
Integrated Sensor ◽  
Modal Expansion ◽  
Modal Expansion Method

Abstract Equations of motion for multi-layer piezoelectric cylindrical shells and the equations of the integrated piezoelectric sensors are derived. The state equation is obtained by solving the equations of motion with modal expansion method. The feedback control, feedforward control, and their combination are applied in the control of forced vibration of the piezoelectric cylindrical shell with integrated sensor and actuators. The simulation and experimental results show that good control effectiveness can be obtained by using the integrated piezoelectric sensor and actuators in conjunction with the combination of feedback and feedforward control methods.

Modal expansion method of analysis for slot-coupled microstrip antenna

1989 ◽  
Vol 25 (20) ◽  
pp. 1338 ◽  
Author(s):  
A. Ittipiboon ◽  
R. Oostlander ◽  
Y.M.M. Antar
Keyword(s):  
Microstrip Antenna ◽  
Expansion Method ◽  
Modal Expansion ◽  
Modal Expansion Method

Evaluating actuator distributions in simply supported truncated thin conical shell with embedded piezoelectric layers

2018 ◽  
Vol 29 (12) ◽  
pp. 2641-2659 ◽  
Author(s):  
Rasa Jamshidi ◽  
Ali A Jafari
Keyword(s):  
Conical Shell ◽  
Piezoelectric Layer ◽  
Cone Angle ◽  
Expansion Method ◽  
Longitudinal Direction ◽  
Modal Expansion ◽  
Simply Supported ◽  
Modal Expansion Method ◽  
Layer Segmentation ◽  
Distributed Actuator

In this investigation, distributed modal actuator forces of simply supported truncated conical shell embedded by a piezoelectric layer are studied. Piezoelectric layer is distributed on the conical shell surface as actuators. Three types of distributions are considered: longitudinal, circumferential, and diagonal distributions. First, electromechanical equations of the conical shell with embedded piezoelectric actuator layer are extracted. Then modal expansion method is used to define independent modal characteristics of the conical shell. For each kind of distribution, three case studies are considered and evaluated. Results showed that in the longitudinal and diagonal distributed actuator, membrane force in the longitudinal direction is the dominant force and in the circumferential distributed actuator, the membrane force in the circumferential direction is the dominant force. The effects of cone angle, piezoelectric thickness, and piezoelectric layer segmentation on modal forces of each distributed actuator are also studied. In circumferential distributed actuator, modal forces increase as the cone angle increases. This phenomenon in the longitudinal and diagonal distributed actuator is almost reversed. The piezoelectric layer segmentation effect on the modal forces distribution is also evaluated, and it showed that this phenomenon has a critical effect on the modal forces distribution.

Hybrid finite-element-modal-expansion method for matched magic T-junction

2002 ◽  
Vol 38 (2) ◽  
pp. 385-388 ◽  
Author(s):  
Zhongxiang Shen ◽  
Choi Look Law ◽  
Cheng Qian
Keyword(s):  
Finite Element ◽  
Expansion Method ◽  
Modal Expansion ◽  
Hybrid Finite Element ◽  
Modal Expansion Method

Modelling of a single-link flexible manipulator system: theoretical and practical investigations

Robotica ◽  
1996 ◽  
Vol 14 (1) ◽  
pp. 91-102 ◽  
Author(s):  
M. O. Tokhi ◽  
A. K. M. Azad
Keyword(s):  
Expansion Method ◽  
Practical Investigations ◽  
Flexible Manipulator ◽  
Experimental Investigations ◽  
Model Parameters ◽  
Modal Expansion ◽  
Modal Expansion Method ◽  
Lagrange’S Equation ◽  
Equivalent Time ◽  
Single Link

SummaryThis paper presents theoretical and experimental investigations into modelling a single-link flexible manipulator system. An analytical model of the manipulator, characterised by an infinite number of modes, is developed using the Lagrange's equation and modal expansion method. This is used to develop equivalent time-domain and frequency-domain working models of the system in state-space and transfer function forms respectively. The model parameters are then estimated experimentally using system's measured input/output data. The model thus obtained is validated through experimentation and results including the effect of payload on system characteristics presented and discussed.

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