Parameter Determination Method of Three-dimensional Analytical Models for Elastic Vibration of Railway Vehicle Carbodies

2021 ◽  
Vol 62 (1) ◽  
pp. 22-27
Author(s):  
Yuki AKIYAMA ◽  
Tadao TAKIGAMI ◽  
Ken-ichiro AIDA
Keyword(s):  
Three Dimensional ◽  
Elastic Vibration ◽  
Analytical Models ◽  
Parameter Determination ◽  
Railway Vehicle ◽  
Determination Method

A three-dimensional analytical model and parameter determination method of the elastic vibration of a railway vehicle carbody

2019 ◽  
Vol 58 (4) ◽  
pp. 545-568 ◽  
Author(s):  
Yuki Akiyama ◽  
Takahiro Tomioka ◽  
Tadao Takigami ◽  
Ken-ichiro Aida ◽  
Takayoshi Kamada
Keyword(s):  
Analytical Model ◽  
Three Dimensional ◽  
Elastic Vibration ◽  
Parameter Determination ◽  
Railway Vehicle ◽  
Determination Method

Study on the vibration suppression of a flexible carbody for urban railway vehicles with a magnetorheological elastomer-based dynamic vibration absorber

2019 ◽  
Vol 234 (7) ◽  
pp. 749-764 ◽  
Author(s):  
Yongpeng Wen ◽  
Qian Sun ◽  
Yu Zou ◽  
Haoming You
Keyword(s):  
Vibration Suppression ◽  
Design Method ◽  
Elastic Vibration ◽  
Parameter Determination ◽  
Railway Vehicle ◽  
Vibration Absorber ◽  
Magnetorheological Elastomer ◽  
Dynamic Vibration Absorber ◽  
Optimum Frequency ◽  
Dynamic Vibration

Magnetorheological elastomer is a new kind of intelligent material that mainly incorporates micron-sized ferromagnetic particles into a polymer. A dynamic vibration absorber that is based on the controllable shear modulus of magnetorheological elastomer is widely used in vibration systems. In the study, a flexible carbody model with a magnetorheological elastomer dynamic vibration absorber is established. A design method of a semiactive dynamic vibration absorber that is based on magnetorheological elastomer is introduced, and the operational principle of the semiactive dynamic vibration absorber is also discussed. To improve the vibration absorption performance of the magnetorheological elastomer dynamic vibration absorber, via multiple regression analysis, the optimal design frequency expressions for both the rigid vibration and the elastic vibration of the carbody are fitted. Parameter determination for the magnetorheological elastomer dynamic vibration absorber is investigated in detail. Then, the effects on the rigid vibration and the elastic vibration with the magnetorheological elastomer vibration absorber both with the passive vibration absorber and without a vibration absorber are analyzed. Finally, Sperling’s riding index is used to evaluate the feasibility and the performance of the magnetorheological elastomer dynamic vibration absorber in a practical application. The results demonstrate that the vibration of the carbody can be effectively reduced by using the magnetorheological elastomer dynamic vibration absorber instead of the dynamic vibration absorber without the magnetorheological elastomer. The magnetorheological elastomer dynamic vibration absorber that is modified by the optimum frequency provides superior vibration reduction performance and improves the riding quality of the railway vehicle.

Validation of a Belt Model for Prediction of Hub Forces from a Rolling Tire4

2009 ◽  
Vol 37 (2) ◽  
pp. 62-102 ◽  
Author(s):  
C. Lecomte ◽  
W. R. Graham ◽  
D. J. O’Boy
Keyword(s):  
Internal Pressure ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Prediction Method ◽  
Analytical Models ◽  
Beam Model ◽  
Impedance Boundary ◽  
Bending Waves ◽  
Tire Rotation ◽  
Three Dimensional Models

Abstract An integrated model is under development which will be able to predict the interior noise due to the vibrations of a rolling tire structurally transmitted to the hub of a vehicle. Here, the tire belt model used as part of this prediction method is first briefly presented and discussed, and it is then compared to other models available in the literature. This component will be linked to the tread blocks through normal and tangential forces and to the sidewalls through impedance boundary conditions. The tire belt is modeled as an orthotropic cylindrical ring of negligible thickness with rotational effects, internal pressure, and prestresses included. The associated equations of motion are derived by a variational approach and are investigated for both unforced and forced motions. The model supports extensional and bending waves, which are believed to be the important features to correctly predict the hub forces in the midfrequency (50–500 Hz) range of interest. The predicted waves and forced responses of a benchmark structure are compared to the predictions of several alternative analytical models: two three dimensional models that can support multiple isotropic layers, one of these models include curvature and the other one is flat; a one-dimensional beam model which does not consider axial variations; and several shell models. Finally, the effects of internal pressure, prestress, curvature, and tire rotation on free waves are discussed.

Research on Three-Dimensional Displacement Measurement Technology of the Beating Heart

2011 ◽  
Vol 403-408 ◽  
pp. 5182-5186
Author(s):  
Sheng Yi Yang ◽  
An Gu ◽  
Meng Li ◽  
Chang Jian Lu
Keyword(s):  
Heart Surgery ◽  
Classical Mechanics ◽  
Three Dimensional ◽  
Beating Heart ◽  
Displacement Measurement ◽  
Surgical Instruments ◽  
Analytical Models ◽  
Measurement Technology ◽  
Position Measurement ◽  
Mechanics Of Materials

In robotic-assisted heart surgery, the method of canceling the relative motion between the surgical site on the heart and the surgical instruments was introduced in this paper. A whisker sensor was designed for three dimensional position measurement in beating heart surgery. Analytical models were developed according to the classical mechanics of materials, and theoretical formulas were derived for displacement measurement. Feasibility and effectiveness of the method were verified by simulation experiments. We can obtain measurements by loading displacement to the whisker sensor, and draw conclusions by comparing the measurements.

scholarly journals Reconstruction of Pressureless Sintered Micron Silver Joints and Simulation Analysis of Elasticity Degradation in Deep Space Environment

2020 ◽  
Vol 10 (18) ◽  
pp. 6368
Author(s):  
Wendi Guo ◽  
Guicui Fu ◽  
Bo Wan ◽  
Ming Zhu
Keyword(s):  
Microstructural Evolution ◽  
Mechanical Response ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Effective Elastic Modulus ◽  
Space Environment ◽  
Analytical Models ◽  
Deep Space ◽  
Sem Images ◽  
Element Analysis

With excellent economy and properties, pressureless sintered micron silver has been regarded as an environmentally friendly interconnection material. In order to promote its reliable application in deep space exploration considering the porous microstructural evolution and its effect on macroscopic performance, simulation analysis based on the reconstruction of pressureless sintered micron silver joints was carried out. In this paper, the deep space environment was achieved by a test of 250 extreme thermal shocks of −170 °C~125 °C, and the microstructural evolution was observed by using SEM. Taking advantage of the morphology autocorrelation function, three-dimensional models of the random-distribution medium consistent with SEM images were reconstructed, and utilized in further Finite Element Analysis (FEA) of material effective elastic modulus through a transfer procedure. Compared with test results and two analytical models, the good consistency of the prediction results proves that the proposed method is reliable. Through analyzing the change in autocorrelation functions, the microstructural evolution with increasing shocks was quantitively characterized. Mechanical response characteristics in FEA were discussed. Moreover, the elasticity degradation was noticed and the mechanism in this special environment was clarified.

scholarly journals 3-D image-based numerical computations of snow permeability: links to specific surface area, density, and microstructural anisotropy

2012 ◽  
Vol 6 (5) ◽  
pp. 939-951 ◽  
Author(s):  
N. Calonne ◽  
C. Geindreau ◽  
F. Flin ◽  
S. Morin ◽  
B. Lesaffre ◽  
...  
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Three Dimensional ◽  
Analytical Models ◽  
Simple Relationship ◽  
Snow Density ◽  
Average Value ◽  
Wide Range ◽  
Snow Samples

Abstract. We used three-dimensional (3-D) images of snow microstructure to carry out numerical estimations of the full tensor of the intrinsic permeability of snow (K). This study was performed on 35 snow samples, spanning a wide range of seasonal snow types. For several snow samples, a significant anisotropy of permeability was detected and is consistent with that observed for the effective thermal conductivity obtained from the same samples. The anisotropy coefficient, defined as the ratio of the vertical over the horizontal components of K, ranges from 0.74 for a sample of decomposing precipitation particles collected in the field to 1.66 for a depth hoar specimen. Because the permeability is related to a characteristic length, we introduced a dimensionless tensor K*=K/res2, where the equivalent sphere radius of ice grains (res) is computed from the specific surface area of snow (SSA) and the ice density (ρi) as follows: res=3/(SSA×ρi. We define K and K* as the average of the diagonal components of K and K*, respectively. The 35 values of K* were fitted to snow density (ρs) and provide the following regression: K = (3.0 ± 0.3) res2 exp((−0.0130 ± 0.0003)ρs). We noted that the anisotropy of permeability does not affect significantly the proposed equation. This regression curve was applied to several independent datasets from the literature and compared to other existing regression curves or analytical models. The results show that it is probably the best currently available simple relationship linking the average value of permeability, K, to snow density and specific surface area.

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