A Dome Shaped PVDF Loudspeaker Model

2011 ◽  
Vol 97 (5) ◽  
pp. 800-808 ◽  
Author(s):  
B. Gazengel ◽  
P. Hamery ◽  
P. Lotton ◽  
A. Ritty
Keyword(s):  
Dynamic Behavior ◽  
Analytical Model ◽  
Cylindrical Cavity ◽  
Theoretical Description ◽  
Differential Pressure ◽  
Second Step ◽  
Circular Membrane ◽  
Static Behavior ◽  
Dome Shape ◽  
Theoretical Results

An analytical model is developed that describes the behavior of a dome-shaped piezoelectric loudspeaker. The loudspeaker consists of a PVDF circular membrane coupled with a rear cylindrical cavity. The dome shape is obtained by means of a static differential pressure held between the two faces of the membrane. The theoretical description of the transducer's behavior is conducted in two steps. In the first step, the static behavior of the membrane is studied in order to obtain the profile of the membrane when submitted to a static differential pressure. In the second step, the dynamic behavior of the membrane is studied. Finally, the theoretical results obtained are compared with experiments in order to evaluate the accuracy of the model.

Transient response of the 1-st order dynamic system with fluctuating parameters

1979 ◽  
Vol 44 (7) ◽  
pp. 2184-2195
Author(s):  
Vladimír Herles ◽  
Jan Čermák ◽  
Antonín Havlíček
Keyword(s):  
Dynamic System ◽  
Dynamic Behavior ◽  
Transient Response ◽  
Flow Model ◽  
Stirred Tank ◽  
Order System ◽  
Random Parameters ◽  
Stirred Tank Reactor ◽  
Tank Reactor ◽  
Theoretical Results

The paper deals with the analysis of the dynamic behavior of the 1st order system with two random parameters. The theoretical results have been compared with experiments on flow model of a stirred tank reactor.

DYNAMIC BEHAVIOR OF TELESCOPIC CRANES BOOM

2013 ◽  
Vol 13 (01) ◽  
pp. 1350010 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Analytical Model ◽  
Constant Velocity ◽  
Steel Beam ◽  
Continuum Approach ◽  
Theoretical Formulation ◽  
Modal Superposition ◽  
Superposition Technique

Telescopic cranes are usually steel beam systems carrying a load at the tip while comprising at least one constant and one moving part. In this work, an analytical model suitable for the dynamic analysis of telescopic cranes boom is presented. The system considered herein is composed — without losing generality — of two beams. The first one is a jut-out beam on which a variable in time force is moving with constant velocity and the second one is a cantilever with length varying in time that is subjected to its self-weight and a force at the tip also changing with time. As a result, the eigenfrequencies and modal shapes of the second beam are also varying in time. The theoretical formulation is based on a continuum approach employing the modal superposition technique. Various cases of telescopic cranes boom are studied and the analytical results obtained in this work are tabulated in the form of dynamic response diagrams.

scholarly journals Modeling of the Eigenfield of a Prestressed Hyperelastic Membrane Encapsulating a Liquid

2006 ◽  
Vol 6 (4) ◽  
pp. 367-385 ◽  
Author(s):  
Ivan. P. Gavrilyuk ◽  
M. Hermann ◽  
A. Timokha ◽  
V. Trotsenko
Keyword(s):  
Boundary Problem ◽  
Approximate Method ◽  
Cylindrical Cavity ◽  
Circular Membrane ◽  
Singular Behavior ◽  
Operator Formulation ◽  
Circular Cylindrical Cavity

AbstractA spectral boundary problem on the eigenfield of an inflated/deflated stretched circular membrane, which is clamped to a circular cylindrical cavity filled with a liquid, is examined. The paper presents an operator formulation of the problem and proposes a new semi-analytical approximate method. The method captures singular behavior of the solution in the pole and at the fastening contour of the membrane.

An Experimental Study of Torsional Vibration Absorbers

2001 ◽  
Author(s):  
Alan G. Haddow ◽  
Steven W. Shaw
Keyword(s):  
Experimental Study ◽  
Dynamic Behavior ◽  
Systematic Study ◽  
Torsional Vibration ◽  
Theoretical Background ◽  
Controlled Environment ◽  
Vibration Absorbers ◽  
Test Apparatus ◽  
First Time ◽  
Theoretical Results

Abstract This paper presents results from tests completed on a rotor system fitted with pendulum-type torsional vibration absorbers. A review of the associated theoretical background is also given and the experimental and theoretical results are compared and contrasted. An overview of the test apparatus is provided and its unique features are discussed. To the best knowledge of the authors, this is the first time that a systematic study of the dynamic behavior of torsional vibration absorbers has been undertaken in a controlled environment.

Dynamic Behavior of a Metamaterial Beam With Embedded Membrane-Mass Structures

2017 ◽  
Vol 84 (12) ◽  
Author(s):  
Jung-San Chen ◽  
I-Ting Chien
Keyword(s):  
Mass Density ◽  
Elastic Membrane ◽  
Circular Membrane ◽  
Negative Mass ◽  
Propagation Behavior ◽  
Resonant Behavior ◽  
Structural Periodicity ◽  
Theoretical Results ◽  
Base Structure ◽  
Good Agreement

Flexural propagation behavior of a metamaterial beam with circular membrane-mass structures is presented. Each cell is comprised of a base structure containing circular cavities filled by an elastic membrane with a centrally loaded mass. Numerical results show that there exist two kinds of bandgaps in such a system. One is called Bragg bandgap caused by structural periodicity; the other is called locally resonant (LR) bandgap caused by the resonant behavior of substructures. By altering the properties of the membrane-mass structure, the location of the resonant-type bandgap can be easily tuned. An analytical model is proposed to predict the lowest bandgap location. A good agreement is seen between the theoretical results and finite element (FE) results. Frequencies with negative mass density lie in the resonant-type bandgap.

Experimental Verification of the Importance of The Nonlinear Curvature in the Response of a Cantilever Beam

1996 ◽  
Vol 118 (1) ◽  
pp. 21-27 ◽  
Author(s):  
T. J. Anderson ◽  
A. H. Nayfeh ◽  
B. Balachandran
Keyword(s):  
Analytical Model ◽  
Cantilever Beam ◽  
Theoretical Investigation ◽  
Experimental Verification ◽  
Dominant Role ◽  
Experimental Results ◽  
Parametrically Excited ◽  
Second Mode ◽  
Quadratic Damping ◽  
Theoretical Results

An experimental and theoretical investigation into the first- and second-mode responses of a parametrically excited slender cantilever beam is presented. Inclusion of quadratic damping in the analytical model significantly improves the agreement between the experimental and theoretical results. In addition, the experimental results verify that the often ignored nonlinear curvature terms play a dominant role in the response of the first mode and that the nonlinear inertia terms play a dominant role in the response of the second mode.

Convergence of a cylindrical liquid shell and the formation of a bore in a rotating fluid

1999 ◽  
Vol 400 ◽  
pp. 355-374
Author(s):  
V. K. KEDRINSKII ◽  
V. V. NIKULIN
Keyword(s):  
Cylindrical Cavity ◽  
Experimental Studies ◽  
Discontinuous Solution ◽  
Rotating Fluid ◽  
Rotationally Symmetric ◽  
Basic Parameters ◽  
Hollow Vortex ◽  
Long Wave Approximation ◽  
Theoretical Results ◽  
Unbounded Fluid

This paper presents the results of experimental studies of a collapsing cylindrical cavity (the convergence of a liquid shell) in a rotating fluid as well as the formation and propagation of a jump (bore) at the interface. The basic parameters of the liquid shell dynamics for a pulsed one-dimensional load are estimated using the equation of cylindrical cavity pulsation in an unbounded fluid. The theoretical model of a rotationally symmetric hydraulic jump moving along the free surface of a hollow vortex is constructed. The jump is simulated by a discontinuous solution of the equations in the long-wave approximation for tornado-like and hollow vortices. For comparison with the experimental data, basic theoretical results are obtained for flows in a hollow vortex with constant circulation and axial velocity varying along the radius of the rotating liquid shell.

Nonlinear Dynamics Behaviors of Ball Screws with Preload Considered

2012 ◽  
Vol 510 ◽  
pp. 304-309 ◽  
Author(s):  
Yong Jiang Chen ◽  
Wen Cheng Tang ◽  
Shi Gen Zhang
Keyword(s):  
Nonlinear Dynamics ◽  
Dynamic Behavior ◽  
Analytical Model ◽  
Rotational Speed ◽  
Nonlinear Dynamic ◽  
Hertzian Contact ◽  
Ball Screw ◽  
Contact Deformation ◽  
Rolling Element ◽  
Equations Of Motions

In order to improve the vibration problem arise when rotational speed of a ball screw is increased, an analytical model is proposed to study the nonlinear dynamic behavior of the ball screw with preload considered. The contact force of each rolling element described according to nonlinear Hertzian contact deformation and the re-circulating mechanism has been taken in to account. A end-type ball screw is selected as an example, the methods of Runge-Kutta-fehlberg is used to solve the equations of motions numerically. It was found that the preload can be useful in controlling the vibration of the system,but the inhibit effect is not proportional to it,in the light of different type of ball screw, corresponding prevention preload is recommended.

Research Regarding the Dynamic Behavior of Linear Hydraulic Servo-Systems

2013 ◽  
Vol 325-326 ◽  
pp. 480-485
Author(s):  
Petrin Drumea ◽  
Corneliu Cristescu ◽  
Catalin Dumitrescu ◽  
Iulian Dutu ◽  
Ioana Ilie
Keyword(s):  
Mathematical Modeling ◽  
Numerical Simulation ◽  
Dynamic Behavior ◽  
Theoretical Research ◽  
Scientific Interest ◽  
Servo Systems ◽  
Hydraulic Motors ◽  
Hydraulic Servo ◽  
Computer Numerical Simulation ◽  
Theoretical Results

The paper presents the theoretical results of extensive research on the dynamic behavior of linear hydraulic motors, carried out in INOE 2000-IHP, in the framework of the NUCLEU Programmer. The research has been conducted both theoretically and experimentally, but, in this paper, is presented only the theoretical research. Theoretical research has taken place with the modern means of mathematical modeling and computer numerical simulation. The article presents some theoretical interested results obtained in the research, results that are of real scientific interest, but, also, with practical value through their use in the design of fluid power components and equipments.

Sign in / Sign up

Export Citation Format

Share Document