Study on Isolation Device for Decrease of Displacement by Using Control of Friction

2005 ◽  
Author(s):  
Masanori Shintani ◽  
Yuichi Hattori ◽  
Tadashi Kotera
Keyword(s):  
Natural Frequency ◽  
Analytical Model ◽  
Friction Force ◽  
External Force ◽  
Simulation Analysis ◽  
Relative Displacement ◽  
Earthquake Damage ◽  
Experimental Results ◽  
Isolation Device ◽  
Analytical Program

This paper deals with an isolation device by using friction force. An isolation device decreases response acceleration and external force. Therefore, earthquake damage is reduced. However, an isolation device has a demerit for large relative displacement. A low horizontal natural frequency decreases the response acceleration. Therefore, in this research, a soft spring is attached to the base of the structure. The purpose of this research is to decrease the relative displacement by using the friction force. Then, an analytical model in consideration of the friction force is proposed, and a simulation is analyzed with well-known earthquake waves. Consequently, as the friction force increases, the results show that the relative displacement decreases. However, it is found that the response acceleration increases. But it is thought that optimal friction force exists, and this force decreases both the response acceleration and the relative displacement. This is considered to change with the properties of earthquake waves. Therefore, it is thought that the response acceleration and the relative displacement are decreased by changing the friction force to the most suitable value for earthquakes. This isolation device is examined with simulation analysis. An experimental device is made under the same conditions as the proposed analytical model. The analytical results are compared with the experimental results, and the validity of an analytical program is examined.

Study on Reducing Relative Displacement of Isolation Device With Friction Surface of Inclination

2008 ◽  
Author(s):  
Masanori Shintani ◽  
Hiroki Tanaka
Keyword(s):  
Friction Coefficient ◽  
Analytical Model ◽  
Friction Force ◽  
Coefficient Of Friction ◽  
Friction Surface ◽  
Relative Displacement ◽  
Random Wave ◽  
Proportional Relation ◽  
Optimal Coefficient ◽  
Isolation Device

This paper deals with an isolation device by using friction force. An isolation device decreases response acceleration and external force. Therefore, earthquake damage is reduced. However, an isolation device has a demerit for large relative displacement. The purpose of this research is to decrease the relative displacement by using the friction force. Then, an analytical model in consideration of the friction force is proposed, and a simulation is analyzed with well-known earthquake waves. Consequently, it is thought that optimal friction force exists, and this force decreases both the response acceleration and the relative displacement. This is considered to change with the properties of earthquake waves. Then, it analyzed using the regular random wave. The result, the proportional relation was seen between relative displacement and the optimal coefficient of friction. Then, by changing a friction coefficient according to relative displacement, it is thought that both response acceleration and relative displacement can be reduced. However, it is difficult to change a friction coefficient. So, in this research, reduction of response acceleration and relative displacement is aimed by changing the angle of a friction surface and friction force. Furthermore, an angle is changed in the middle of a slope. It is thought that it becomes possible to reduce response acceleration and relative displacement further. An experimental device is made under the same conditions as the proposed analytical model. The experimental results are compared with the analytical results.

Study on Two-Dimensions Base-Isolating Device for Reduction of Displacement by Using Friction Force

2009 ◽  
Author(s):  
Tomoyuki Makino ◽  
Masanori Shintani
Keyword(s):  
Friction Force ◽  
Friction Surface ◽  
Seismic Waves ◽  
Simulation Analysis ◽  
Vertical Direction ◽  
Relative Displacement ◽  
Two Dimensions ◽  
Analysis Model ◽  
Restoring Force ◽  
Isolation Device

This paper deals with research of new isolation device with reduction of horizontal relative displacement by using friction force and reduction of vertical response acceleration and relative displacement by using spring and friction force. The isolation device is using a friction surface. The friction surface is subjected to acts on the slope plate. The restoring-force of horizontal direction is given to the isolation device from elastic force of a compression spring attached to the base. The restoring-force always works in the direction of the center. Therefore, the frictional force and the restoring-force are both proportional to the displacement. The restoring-force of the vertical direction is given to the isolation device from compression springs and draft springs. Simulation analysis was performed under various conditions using this analysis model. Condition reducing both response acceleration and displacement effectively is calculated on various conditions using the analysis model. Furthermore, an experiment is conducted using the experimental device. The experiment is conducted by an imagination wave. Analysis is also conducted on the same conditions. The results of the experiment are compared with the results of the analysis. The performance of the isolation device is examined. The validity of an analysis model is examined. As a result of conducting the analysis and an experiment with this model, it was shown that response acceleration and relative displacement can be reduced successfully. The validity of an analysis model is shown. Next, it analyzes by actual seismic waves. The performance of isolation equipment in actual seismic waves is examined and shown.

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.

Vibration Characteristics of Rotating Thin Disks—Part I: Experimental Results

2012 ◽  
Vol 79 (4) ◽  
Author(s):  
Ramin M. H. Khorasany ◽  
Stanley G. Hutton
Keyword(s):  
Frequency Response ◽  
Natural Frequency ◽  
Linear Theory ◽  
Lateral Force ◽  
Vibration Characteristics ◽  
Experimental Results ◽  
Rotating Disks ◽  
Critical Speeds ◽  
Applied Forces ◽  
Thin Disks

Analysis of the linear vibration characteristics of unconstrained rotating isotropic thin disks leads to the important concept of “critical speeds.” These critical rotational speeds are of interest because they correspond to the situation where a natural frequency of the rotating disk, as measured by a stationary observer, is zero. Such speeds correspond physically to the speeds at which a traveling circumferential wave, of shape corresponding to the mode shape of the natural frequency being considered, travel around the disk in the absence of applied forces. At such speeds, according to linear theory, the blade may respond as a space fixed stationary wave and an applied space fixed dc force may induce a resonant condition in the disk response. Thus, in general, linear theory predicts that for rotating disks, with low levels of damping, large responses may be encountered in the region of the critical speeds due to the application of constant space fixed forces. However, large response invalidates the predictions of linear theory which has neglected the nonlinear stiffness produced by the effect of in-plane forces induced by large displacements. In the present paper, experimental studies were conducted in order to measure the frequency response characteristics of rotating disks both in an idling mode as well as when subjected to a space fixed lateral force. The applied lateral force (produced by an air jet) was such as to produce displacements large enough that non linear geometric effects were important in determining the disk frequencies. Experiments were conducted on thin annular disks of different thickness with the inner radius clamped to the driving arbor and the outer radius free. The results of these experiments are presented with an emphasis on recording the effects of geometric nonlinearities on lateral frequency response. In a companion paper (Khorasany and Hutton, 2010, “Vibration Characteristics of Rotating Thin Disks—Part II: Analytical Predictions,” ASME J. Mech., 79(4), p. 041007), analytical predictions of such disk behavior are presented and compared with the experimental results obtained in this study. The experimental results show that in the case where significant disk displacements are induced by a lateral force, the frequency characteristics are significantly influenced by the magnitude of forced displacements.

Study on a Novel MEMS High G Acceleration Sensor

2012 ◽  
Vol 490-495 ◽  
pp. 499-503
Author(s):  
Ping Li ◽  
Yun Bo Shi ◽  
Jun Liu ◽  
Shi Qiao Gao
Keyword(s):  
Resonant Frequency ◽  
Natural Frequency ◽  
Impact Load ◽  
Hopkinson Bar ◽  
Experimental Results ◽  
Structure Parameters ◽  
Acceleration Sensor ◽  
Piezoresistive Effect ◽  
Sensor Structure ◽  
The Impact

This paper presents a novel MEMS high g acceleration sensor based on piezoresistive effect. For the designed sensor structure, the formula of stress, natural frequency and damping was derived in theory, and the resonant frequency can up to 500kHz. After the structure parameters were designed, the sensor was fabricated by the standard processing technology, and the sensitivity was tested by Hopkinson bar. According to the experimental results, the sensitivity of the high g acceleration sensor is 0.125μV/g at the impact load of 164,002g.

Experimental and numerical investigation of the thermomechanical load on a turbine housing in a radial turbocharger

2021 ◽  
pp. 095440702110521
Author(s):  
Shaolin Chen ◽  
Hong Zhang ◽  
Liaoping Hu ◽  
Guangqing He ◽  
Fen Lei ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Fatigue Life ◽  
Simulation Analysis ◽  
Simulation Method ◽  
Testing Temperature ◽  
Experimental Results ◽  
Maximum Temperature ◽  
Monitoring Point ◽  
Turbine Housing

The fatigue life of turbine housing is an important index to measure the reliability of a radial turbocharger. The increase in turbine inlet temperatures in the last few years has resulted in a decrease in the fatigue life of turbine housing. A simulation method and experimental verification are required to predict the life of a turbine housing in the early design and development process precisely. The temperature field distribution of the turbine housing is calculated using the steady-state bidirectional coupled conjugate heat transfer method. Next, the temperature field results are considered as the boundary for calculating the turbine housing temperature and thermomechanical strain, and then, the thermomechanical strain of the turbine housing is determined. Infrared and digital image correlations are used to measure the turbine housing surface temperature and total thermomechanical strain. Compared to the numerical solution, the maximum temperature RMS (Root Mean Square) error of the monitoring point in the monitoring area is only 3.5%; the maximum strain RMS error reached 11%. Experimental results of temperature field test and strain measurement test show that the testing temperature and total strain results are approximately equal to the solution of the numerical simulation. Based on the comparison between the numerical calculation and experimental results, the numerical simulation and test results were found to be in good agreement. The experimental and simulation results of this method can be used as the temperature and strain (stress) boundaries for subsequent thermomechanical fatigue (TMF) simulation analysis of the turbine housing.

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.

Simulation Research on Stress – Damage Law of the Blood Cells

2012 ◽  
Vol 482-484 ◽  
pp. 776-779
Author(s):  
Xiong Xie ◽  
Jian Ping Tan
Keyword(s):  
Blood Cell ◽  
External Force ◽  
Blood Cells ◽  
Simulation Analysis ◽  
Artificial Organs ◽  
Simulation Research ◽  
Axial Diameter ◽  
Concave Shape ◽  
Damage Law ◽  
Stress Damage

Through simulation analysis of the blood cell by Abques under the function of the different pressures, the change of the cell’s axial diameter and the importance of the effect of external force and double concave shape on the erythrocyte’s deformability are obtained. It lays the foundation for the research artificial organs lubrication.

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