Application with Theory of Vibration Equivalence on Reliability Test Bed of Train Brake System

2010 ◽  
Vol 34-35 ◽  
pp. 1978-1982 ◽  
Author(s):  
Xiao Yan Wang ◽  
Meng Ling Wu ◽  
Zhong Kai Chen
Keyword(s):  
Random Vibration ◽  
Brake System ◽  
Quantitative Relation ◽  
Reliability Test ◽  
Test Bed ◽  
Sinusoidal Vibration ◽  
Equivalency Theory ◽  
Environmental Vibration ◽  
Circular Frequency ◽  
Vibrating Table

In order to design a reliability test bed for train brake system, theory of vibration equivalence was used to represent in laboratory the environmental vibration. Firstly, the root mean square (RMS) value of the acceleration was calculated for train brake system according to IEC 61373. Then, a configuration of vibrostand was proposed for the reliability test bed, which was mainly composed of vibrating table-board, vibrator motor, damp and four vibrating springs, as shown in figure 2. After that, an equation was got according to the RMS equivalency theory. Finally, the equation was solved according to the feature of the vibrostand. And the quantitative relation was got for exciting force F0, shock excitation circular frequency ω and spring rate k. The method can also be used on other occasions where sinusoidal vibration is needed to replace random vibration.

EXPERIMENTAL STUDY ON CONCRETE PERMEABILITY AFFECTED BY ENVIRONMENTAL VIBRATION

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Xue-Feng Ma ◽  
Jian-Qing Bu
Keyword(s):  
Measurement Data ◽  
Vibration Energy ◽  
Middle Portion ◽  
Sinusoidal Vibration ◽  
Concrete Permeability ◽  
Impedance Technique ◽  
Environmental Vibration ◽  
Vibrating Table ◽  
Vibration Time ◽  
Vibration Parameters

This study investigates the effect of environmental vibrations on concrete permeability. Based on published field measurement data and relevant references, two different sinusoidal vibration parameters (5 Hz/4 mm and 20 Hz/2 mm) are selected and applied to a newly constructed concrete by a vertical vibrating table and AC impedance technique. The concrete permeability is examined, and the influence of some factors including different vibration time (before initial curdle, between initial curdle and finial curdle, and after final curdle) and different vibration energy are discussed. From the experimental results, the following conclusions can be drawn. Irrespective of whether or not the concrete is vibrated, the uniformity inside the concrete along the direction of concrete pouring is more discrete in the upper and lower part of the concrete. Furthermore, the permeability at both ends of the concrete is larger than that in the middle portion. The newly constructed concrete's permeability is increased when the vibration energy is lowered, and decreased when the vibration energy is increased, and the new constructed concrete permeability affected by environment vibration obviously before initial curdle time.

Inductive Estimation Arithmetic for Random Vibration Data

2011 ◽  
Vol 219-220 ◽  
pp. 1113-1116
Author(s):  
Yong Jie Zhang ◽  
Xiao Hu Zhang ◽  
Bin Tuan Wang
Keyword(s):  
Data Processing ◽  
Numerical Experiments ◽  
Random Vibration ◽  
Measured Data ◽  
Reliability Test ◽  
Vibration Data ◽  
Inductive Methods

The vibration data processing of environmental spectrum is an important part of environmental reliability test for the aircraft. Based on the inductive methods for environmental measured data of vibration, an inductive arithmetic is employed to estimate the random vibration data of aircraft surface in Matlab system. Numerical experiments show that the inductive estimation arithmetic is effective, reliable and applicable for the environmental measured data of random vibration.

On Environmental Vibration Power Spectra and Accelerated Testing for Medical Devices

1999 ◽  
Author(s):  
Jingshu Wu ◽  
Ruichong Zhang ◽  
Karl K. Stevens
Keyword(s):  
Medical Devices ◽  
Random Vibration ◽  
Power Spectra ◽  
Field Testing ◽  
Accelerated Testing ◽  
Quality Analysis ◽  
Ground Vehicles ◽  
Operational Conditions ◽  
Analysis And Design ◽  
Environmental Vibration

Abstract This paper proposes field-testing-based power spectra of vibration in such environments as helicopters and ground vehicles. The spectra could then be used as important input data to guide accelerated testing, quality analysis and design for medical devices (or products) used in the aforementioned transportation means. Specifically, a broad spectrum of environmental vibration is first measured in a series of field vibration tests at various locations inside the transportation means and at different operational conditions (e.g., take-off, cruise, and landing conditions if medical devices are used in helicopters). Consequently, comprehensive field-testing-based power spectra are constructed, in an attempt to catch the inherent nature of random vibration environment in each and every type of the transportation means, which is not adequately specified in standard codes. As one of the applications of the proposed spectra, accelerated random vibration testing for medical devices used in either helicopters or ground vehicles is proposed, which could be used not only for product field life prediction but also for its consequent reliability analysis and design.

Experiments on clearance identification in cantilever beams reduced from artillery mechanism

2016 ◽  
Vol 231 (6) ◽  
pp. 1010-1032 ◽  
Author(s):  
Jie Liu ◽  
Bing Li ◽  
Wei Jin ◽  
Luofeng Han ◽  
Shuanglu Quan
Keyword(s):  
Cantilever Beam ◽  
Contact Stiffness ◽  
Influence Factors ◽  
Quantitative Relation ◽  
Test Bed ◽  
Nonlinear Identification ◽  
Dynamic Information ◽  
Restoring Force ◽  
Identification Process ◽  
Clearance Nonlinearity

Clearances existing in artillery mechanism cause the muzzle disturbance and reduce the artillery firing accuracy. If the parameters of the clearance nonlinearity can be identified by taking advantage of the dynamic information, the quantitative relation between the clearance and muzzle disturbance can be established, and then the clearances of such nonlinear system can be controlled in a reasonable range to improve the artillery firing accuracy. This paper proposed a nonlinear identification method for the cantilever beam with clearances reduced from barrel-cradle structure. A modified restoring force surface method is proposed to identify the clearance value of the cantilever beam in time domain, and then a modified nonlinear identification through feedback of outputs method, i.e., reduced-order nonlinear identification through feedback of the output method, is proposed to recognize the related contact stiffness in frequency domain. The feasibility of the combined identification process is verified by a cantilever beam with two clearances in simulation, and a test-bed with adjusted clearance and contact stiffness which is regardless of other nonlinear factors by adjusting the position of the clearance and excitation method was designed to verify the effectiveness of this method. In the end, some influence factors of this identification process are discussed in detail. The results show that the proposed methods can identify clearance-nonlinearity parameters with high precision.

scholarly journals Dynamic Modeling and Experimental Verification of Bus Pneumatic Brake System

2015 ◽  
Vol 9 (1) ◽  
pp. 52-57
Author(s):  
Lu Yi ◽  
Xu Bowen ◽  
Guo Bin
Keyword(s):  
Computer Simulation ◽  
Dynamic Characteristic ◽  
Dynamic Modeling ◽  
Experimental Verification ◽  
Brake System ◽  
Test Bed ◽  
Mathematical Relationship ◽  
Simulation Results ◽  
Mathematical Derivation ◽  
Fitness Analysis

The dynamic characteristic of pneumatic brake system is very important, so the full-parameter model of the pneumatic brake system was established on the base of the technology of computer simulation. Its key brake components include brake valve, relay valve, diaphragm brake chamber and pneumatic circuit. AMESim was first introduced on the basis of mathematical derivation. So the multivariable complexity derivation, nonlinear mathematical relationship can be avoided. The model can be used for the bus brake system multi-parameter simulation and design. A pneumatic brake system test-bed was designed to verify the accuracy of the model. It can measure the dynamic characteristic and the output response coordination of each component. It was showed that the simulation results were fit to the experiment results. For the deviation, the explanation and analysis were also given. The response hysteresis of the brake system is mainly caused by the rubber diaphragm deformation in brake chamber. This research laid the foundation for the further structural optimization of brake components and fitness analysis of the pneumatic brake system.

HUMAN SENSORY EVALUATION OF VIBRATIONS INSIDE TALL BUILDINGS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Chihiro Suzuki ◽  
Takashige Ishikawa
Keyword(s):  
Sensory Evaluation ◽  
Random Vibration ◽  
Tall Buildings ◽  
Sinusoidal Vibration ◽  
Maximum Acceleration ◽  
Long Period ◽  
Fast Fourier Transform Analysis ◽  
Wide Range ◽  
The Relationship ◽  
Frequent Problem

Long-period vibrations felt by residents or workers in tall buildings due to wind or earthquake are a frequent problem. Considering the fact that vibration by wind or earthquake is dynamic, we investigated a wide range of random vibration, including long-period vibration. We focused on sensory evaluation and investigated the relationship between perception or psychological quantity (magnitude of anxiety or discomfort) and random vibration. In this study, we performed experiments using actual vibrations in detached houses for original waveforms. The results show the possibility of estimation using the predominant frequency in a fast Fourier transform analysis and maximum acceleration for perception and psychological evaluation. Random vibration is hardly perceived compared with sinusoidal vibration, and anxiety or discomfort is hardly felt. We determined a range in which subjects perceive random vibration but do not feel anxiety or discomfort.

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