Study on Nonlinear Vibration of Continuum System With Gaps Considering Energy Dissipated by Collision

2004 ◽  
Author(s):  
Masanori Shintani ◽  
Hiroyuki Ikuta ◽  
Tadashi Kotera
Keyword(s):  
Kinetic Energy ◽  
Nonlinear Vibration ◽  
Analytical Model ◽  
Experimental Results ◽  
Thin Plates ◽  
Random Waves ◽  
Restoring Force ◽  
Collision Effect ◽  
Experimental Apparatus ◽  
Energy Dissipated

This paper deals with nonlinear vibration of a continuum system with gaps under random waves considered collision phenomena. In order to investigate this nonlinear vibration characteristic, experiments are carried out with an experimental apparatus consisting of a nonlinear vibration system. Moreover, an analytical model of the cubic equation is proposed based on the restoring force characteristics in the experiments. This analytical model is used for the simulation analysis, and its results are compared with the experimental results. However, the results show differences between thick plates and thin plates in the root-mean-square (R.M.S.) value of the response acceleration and the transfer function. The ratio of the kinetic energy of the experimental results and the simulation results is investigated. Consequently, energy is dissipated in the experiments. It is found that the energy dissipated by collision phenomena causes these results. In order to measure the coefficient of restitution by the collision phenomena between the plate and the mass, an experimental apparatus for the collision effect is made. Experiments are carried out with this apparatus. The experimental results agree with part of the results of the ratios of kinetic energy. It is clear that the analytical model in consideration for the energy dissipated by the collision effect is required.

Vibration Characteristic Evaluation of Nonlinear Vibration Systems With Gaps Considering Energy Dissipation by Collision

2005 ◽  
Author(s):  
Masanori Shintani ◽  
Hiroyuki Ikuta ◽  
Hiroyuki Shume
Keyword(s):  
Nonlinear Vibration ◽  
Analytical Model ◽  
Damping Ratio ◽  
Experimental Results ◽  
Experimental Result ◽  
Vibration Characteristic ◽  
Random Waves ◽  
Restoring Force ◽  
Dissipation Energy ◽  
Experimental Apparatus

This paper deals with nonlinear vibration of a continuum system with gaps under random waves considered collision phenomena. In order to investigate this nonlinear vibration characteristic, experiments are made with an experimental apparatus consisting of a nonlinear vibration system. A 2.3mm thick plate is used for the collision phenomena experiments. Moreover, an analytical model of the cubic equation is proposed based on the restoring force characteristics in the experiments. This analytical model is used for the simulation analysis, and the results are compared with the experimental results. However, the Root- Mean- Square (R.M.S.) values of the response acceleration of the analytical results are larger than R.M.S. values of the response acceleration of the experimental result. The difference of these results indicates that energy is dissipated in the collision phenomena. Then, the coefficient of restitution by the collision phenomenon between mass and plate is measured from the experiments. In the analysis, the dissipation energy is replaced with an equivalent damping ratio. The simulations are calculated by using this modified analysis. Consequently, the simulation results agree well with the experimental results.

Evaluation of Energy Absorption in Nonlinear Vibration System With Gaps

2005 ◽  
Author(s):  
Masanori Shintani ◽  
Hiroyuki Ikuta ◽  
Hajime Takada
Keyword(s):  
Nonlinear Vibration ◽  
Energy Absorption ◽  
Analytical Model ◽  
Random Waves ◽  
Vibration System ◽  
Restoring Force ◽  
Acceleration Level ◽  
Experimental Apparatus ◽  
Input Acceleration ◽  
Nonlinear Vibration System

This paper deals with nonlinear vibration characteristics of a continuum system with collision phenomena under random waves with gaps. In order to investigate such a nonlinear vibration characteristic, an experimental apparatus consisting of a nonlinear vibration system was made. Moreover, we propose an analytical model based on the restoring force characteristics of the experiments. In this report, the size of the gap between a mass and a plate is set to 0.5mm or 1.0mm. For this experimental model we also propose an analytical model. We use plates of 1.6mm thickness in the collisions both in the experiment and the analysis. The analytical model is based on an elasto-plasticity solid model. When considering the coefficients of restitution or energy absorption, the experimental results nearly agree with the analytical results [10]. We found that the rate of a collision changes with the size of the gap at each input acceleration level. As the gap size widens, energy absorption decreases for each input acceleration level. Consequently, in order to increase the energy absorption, it becomes necessary to increase the rate of the collision.

Study on Analytical Model of Nonlinear Vibration for Elastic Plates With Gaps Under Random Waves

2004 ◽  
Vol 126 (4) ◽  
pp. 504-509 ◽  
Author(s):  
Masanori Shintani ◽  
Manabu Hamai
Keyword(s):  
Nonlinear Vibration ◽  
Analytical Model ◽  
Force Characteristic ◽  
Solid Model ◽  
Random Waves ◽  
Elastic Plates ◽  
Analysis Model ◽  
Restoring Force ◽  
Elasto Plasticity ◽  
Force Characteristics

In this paper, an analytical model for the nonlinear elastic-plastic vibration for long plates with gaps subjected to random vibrations is considered. The nonlinear vibration is caused by the collision phenomena between a mass through a gap and plates with thickness of 0.5, 0.6, and 0.8 mm. An elastic perfectly plastic solid material is assumed in some cases, which adds another aspect to the nonlinear behavior of the system. The material characteristic of the steel is assumed to be an elasto-plasticity solid model. A restoring force characteristic is obtained as the nonlinear vibration of a cubic equation for 0.5, 0.6, and 0.8 mm, the thickness of the plates by experiments. Now the analytical model is proposed by the elasto-plasticity solid model. The relation between the displacement and the force is described by a complicated equation. The curve from the analytical model is called a deflection curve. The results by the analytical model are compared with the results by the experimental model. The restoring force characteristics by the analysis agree with those of the experiment. The restoring force characteristics of the analysis are described using cubic equations. The simple analysis model for evaluation of the vibration characteristic of the nonlinear vibration system, which performs collision vibration with gaps, is proposed by elasto-plasticity solid model in this paper. The results of this proposed analytical model agree with the experimental results better than the results of the minimum of error of square.

Piezoelectric Actuators for Distributed Vibration Excitation of Thin Plates: A Comparison Between Theory and Experiment

1993 ◽  
Vol 115 (3) ◽  
pp. 332-339 ◽  
Author(s):  
R. L. Clark ◽  
M. R. Flemming ◽  
C. R. Fuller
Keyword(s):  
Analytical Model ◽  
Piezoelectric Actuators ◽  
Experimental Results ◽  
Thin Plates ◽  
Simply Supported ◽  
Forcing Function ◽  
Vibration Excitation ◽  
Theoretical Predictions ◽  
Multiple Patches ◽  
Theory And Experiment

Experimental results from vibration excitation of a simply supported plate with multiple patches of piezoceramic material bonded to the surface are compared to theoretical predictions for the vibration response. Results demonstrate that modes can be selectively excited depending on the chosen phasing of the voltage supplied to each actuator. In addition, experimental results indicate that the analytical model can be accurately used to predict the forcing function associated with the piezoceramic patch.

scholarly journals Generalized analytical model based on harmonic coupling for hybrid plasmonic modes: comparison with numerical and experimental results

2015 ◽  
Vol 23 (21) ◽  
pp. 27376 ◽  
Author(s):  
Mitradeep Sarkar ◽  
Jean-François Bryche ◽  
Julien Moreau ◽  
Mondher Besbes ◽  
Grégory Barbillon ◽  
...  
Keyword(s):  
Analytical Model ◽  
Experimental Results ◽  
Model Based

Convective Losses From Cavity Solar Receivers—Comparisons Between Analytical Predictions and Experimental Results

1983 ◽  
Vol 105 (1) ◽  
pp. 29-33 ◽  
Author(s):  
A. M. Clausing
Keyword(s):  
Experimental Data ◽  
Experimental Evidence ◽  
Analytical Model ◽  
Excellent Agreement ◽  
Experimental Results ◽  
Simple Analytical Model ◽  
Refined Model ◽  
Wall Area

Cavity solar receivers are generally believed to have higher thermal efficiencies than external receivers due to reduced losses. A simple analytical model was presented by the author which indicated that the ability to heat the air inside the cavity often controls the convective loss from cavity receivers. Thus, if the receiver contains a large amount of inactive hot wall area, it can experience a large convective loss. Excellent experimental data from a variety of cavity configurations and orientations have recently become available. These data provided a means of testing and refining the analytical model. In this manuscript, a brief description of the refined model is presented. Emphasis is placed on using available experimental evidence to substantiate the hypothesized mechanisms and assumptions. Detailed comparisons are given between analytical predictions and experimental results. Excellent agreement is obtained, and the important mechanisms are more clearly delineated.

scholarly journals Mathematical modelling of the overflowing cylinder experiment

2003 ◽  
Vol 474 ◽  
pp. 275-298 ◽  
Author(s):  
P. D. HOWELL ◽  
C. J. W. BREWARD
Keyword(s):  
Free Surface ◽  
Surfactant Concentration ◽  
Dynamic Properties ◽  
Vertical Cylinder ◽  
Surfactant Solution ◽  
Surface Concentration ◽  
Experimental Results ◽  
Surface Velocity ◽  
Experimental Apparatus ◽  
Finite Distance

The overflowing cylinder (OFC) is an experimental apparatus designed to generate a controlled straining flow at a free surface, whose dynamic properties may then be investigated. Surfactant solution is pumped up slowly through a vertical cylinder. On reaching the top, the liquid forms a flat free surface which expands radially before over flowing down the side of the cylinder. The velocity, surface tension and surfactant concentration on the expanding free surface are measured using a variety of non-invasive techniques.A mathematical model for the OFC has been previously derived by Breward et al. (2001) and shown to give satisfactory agreement with experimental results. However, a puzzling indeterminacy in the model renders it unable to predict one scalar parameter (e.g. the surfactant concentration at the centre of the cylinder), which must be therefore be taken from the experiments.In this paper we analyse the OFC model asymptotically and numerically. We show that solutions typically develop one of two possible singularities. In the first, the surface concentration of surfactant reaches zero a finite distance from the cylinder axis, while the surface velocity tends to infinity there. In the second, the surfactant concentration is exponentially large and a stagnation point forms just inside the rim of the cylinder. We propose a criterion for selecting the free parameter, based on the elimination of both singularities, and show that it leads to good agreement with experimental results.

scholarly journals Effect of Ultrasonic Treatment on Radon Exhalation from Porous Media: An Experimental Case Study

2018 ◽  
Vol 10 (9) ◽  
pp. 3005
Author(s):  
Ling-feng Xie ◽  
Shu-liang Zou ◽  
Xiang-yang Li ◽  
Chang-shou Hong ◽  
Hong Wang ◽  
...  
Keyword(s):  
Porous Media ◽  
Moisture Content ◽  
Ultrasonic Wave ◽  
Linear Correlation ◽  
Experimental Results ◽  
Radon Exhalation Rate ◽  
Exhalation Rate ◽  
Radon Exhalation ◽  
Experimental Apparatus ◽  
Positive Linear Correlation

Radon is internationally recognized as one of the seven seismic precursors. A self-assembly ultrasonic generator and experimental apparatus for radon measurement were utilized to explore the radon exhalation regularities of water-bearing porous media under different ultrasonic intensities. The experimental results showed that there was a coupling relationship among radon exhalation rate, moisture content, and ultrasonic frequency. With the increase of the frequency of the ultrasonic wave, its effect on the promotion of radon exhalation rate was found to be a more obviously positive linear correlation. The radon exhalation rate, which could climb to a maximum value of 0.179 Bq·m−2·s−1 in a naturally air-dried sample, increased at first and then decreased along with increased moisture content. Moreover, this study found that the ultrasonic wave had the most remarkable promoting effects on the radon exhalation rate of porous media with high moisture content, and there is a positive linear correlation between the growth rate of the radon exhalation rate and moisture content. The experimental results could provide a beneficial reference for the continual monitoring of radon in a seismically active belt and an explanation of radon anomalies; however, the proposed experimental model was simplified, so further insights are strictly required for a reliable correlation with the real monitoring of radon in a seismically active belt.

scholarly journals Adaptive Broadcasting Mechanism for Bandwidth Allocation in Mobile Services

2014 ◽  
Vol 2014 ◽  
pp. 1-14
Author(s):  
Gwo-Jiun Horng ◽  
Chi-Hsuan Wang ◽  
Chih-Lun Chou
Keyword(s):  
Analytical Model ◽  
Bandwidth Allocation ◽  
Data Dissemination ◽  
Data Access ◽  
Experimental Results ◽  
Bandwidth Utilization ◽  
Access Latency ◽  
The Mean ◽  
Access Efficiency ◽  
Broadcast Program

This paper proposes a tree-based adaptive broadcasting (TAB) algorithm for data dissemination to improve data access efficiency. The proposed TAB algorithm first constructs a broadcast tree to determine the broadcast frequency of each data and splits the broadcast tree into some broadcast wood to generate the broadcast program. In addition, this paper develops an analytical model to derive the mean access latency of the generated broadcast program. In light of the derived results, both the index channel’s bandwidth and the data channel’s bandwidth can be optimally allocated to maximize bandwidth utilization. This paper presents experiments to help evaluate the effectiveness of the proposed strategy. From the experimental results, it can be seen that the proposed mechanism is feasible in practice.

A Simplified Method for Determining Acoustic and Tube Eigenfrequencies in Heat Exchangers

1982 ◽  
Vol 104 (3) ◽  
pp. 175-179 ◽  
Author(s):  
J. Planchard ◽  
F. N. Remy ◽  
P. Sonneville
Keyword(s):  
Eigenvalue Problem ◽  
Sound Velocity ◽  
Heat Exchangers ◽  
Fluid Structure Interaction ◽  
Coupled System ◽  
Experimental Results ◽  
Structure Interaction ◽  
Experimental Apparatus ◽  
Tube Arrays ◽  
Simplified Method

A method of computation of eigenfrequencies of large tube arrays is presented, which is based on homogenization techniques. It is supposed that the fluid is compressible, at rest and contained in a cavity; the bundle geometry is assumed to be repetitive; an equivalent sound velocity through the tubes can then be calculated, and the fluid-structure interaction is taken into account. A new eigenvalue problem is so obtained, defined over a simpler domain, i.e., the region occupied by both fluid and tubes; it is then easy to solve it for computing the eigenfrequencies of the coupled system. Numerical and experimental results are presented and some details of the experimental apparatus are given.

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