Research on Water Pump Isolation Parameters Based on Power Flow

Vibration parameter of water pump is studied by power flow theory, water pump isolation vibration system can be simplified a single-deck isolation system model, by using electric-machine (E-F) analog method, the curves of foundation speed amplitude and power flow are drawn, the results show that the inertia block has clearly reduced the vibration power flow and speed amplitude, increasing the mass of inertia block can decrease the first peak point and make the first peak point moving toward the low frequency direction, increasing surface density of the basement can decrease input power flow and the vibration of basement.

Simulation and Optimization Design Based on Adams Engine Mounting System

The content of this subject research is to conduct optimization for engine mounting system, and through optimization, it can make the vibration between engine and vehicle body achieve a minimum, using Adams software for simulation. It studies the isolation vibration of the engine mounting system and conducts goal optimization for fixed frequency. This paper uses two methods for optimization. One is to use the rational allocation of fixed frequency to optimize the fixed frequency, and the other is to use energy decoupling method to optimize the fixed frequency. It uses Adams software for simulation of the optimized fixed frequency and conducts comparison of simulated results. The simulated results show that the optimized energy distribution situation almost achieves 90%. Compared with original data, decoupling degree also has a very great improvement, illustrating that the optimized data has greater effect for the isolated vibration of engine, in order to further verify the feasibility of optimization design method.

Study on Damping Measures of Pump Piping Vibration Isolation Device

The problem about pump piping system vibration isolation that is hard to be solved at the present stage in the practice engineering was studied in this paper. Damping measures which is the necessary measure is proposed in this study. Theoretical analysis is given to the main parameter (thickness) of the influences of the damping. Based on the free damping measure, constrained damping measures was proposed and verified by the experiments. The results show that the damping effect was improved with the increasing of the thickness. Under the same conditions, the effect of the constrained damping measures was better than the free damping measures. The results have significant guidance in the isolation vibration of the pump system.

Experimental Research on Isolation Vibration Effect of Engine Suspension Based on Power Flow

The acceleration and force sensors are taken as the measurement parameter,vibration power flow analysis is conducted to the data collected using MATLAB software,the results show that validity of engine suspension vibration is intuitively judged using the power flow,it is a evaluation index,moreover,it is not only convenient measurement,but also the influence of phase difference between the measured parameters to vibration isolation effect is not needed consider.

Experimental Determination of Sound Absorption Coefficients of Four Types of Malaysian Wood

Currently, one of the important topics in acoustic science is noise control. It is important to control the noise in order to minimize extraneous noise in rooms, buildings, and our environment. Noise control can be achieved by reducing the intensity of sound to the level that is not harmful to human ear. There are four basic principles employed to reduce noise which is absorption, isolation, vibration isolation, and vibration damping. In fact, the most recognized technique to reduce noise is sound absorption on the materials itself. Sound absorption on material such as wood and porous material have been developed and studied by few researchers. Materials that reduce the sound intensity as the sound wave passes through it by the phenomenon of absorption are called sound absorptive materials. There are lot of methods can be used on determining the sound absorption coefficient of materials. In this paper, a preliminary work has been carried out experimentally to determine the sound absorption coefficient of four types of Malaysian wood. They are Tapang (Koompassia excels), Pulai (Alstonai angustiloba), Selunsor merah (Tristianiopsis beccariana) and Jelutong (Dyera polyphylla). The test was performed using the ASTM E1050-98/ISO 10534-2 (American Society for Testing and Material) standards for the sound absorption coefficient testing. This method is known as impedance tube method (Two-Microphone Method). The absorption coefficient depends on the frequencies. In this study the values of the frequencies used was in the range from 350 Hz to 1000 Hz.

Investigation on Vibration Reduction Effects of a New Vibration Isolation Module for Pier Foundation

This paper presents a new vibration isolation module which is set somewhere out of pier footings of footbridges. The isolation vibration effect of the vibration isolation module was analysed by means of experiment and FEM analysis. The attenuation decibels of the vibration strength were measured and researched under various working conditions. Making use of the finite element program, the new vibration isolation module was simulated and calculated. That the calculated results were in good agreement with the measured ones indicated the reliability of the numerical model. The simulation and measured results suggest that vibration reduction effects are satisfactory. The results can provide reference for vibration attenuation and vibration isolation of footbridges.

3D Analysis of Vibration Isolation by Wave Impeding Block in Non-Uniform Layered Ground under Horizontal-Rocking Coupled Loading

The thin-layered method (TLM) is very efficient to the wave propagation in layered ground and boundary element method (BEM) is very precise to solve infinite domain problems. In order to study the isolation vibration effectiveness of non-uniform three-dimensional (3D) layered ground wave impeding block (WIB), this paper is accomplished with the aid of a 3D semi-analytical BEM based on TLM, on which the Green’s function is regarded as fundamental solution of a stratified half-space. Then the active isolation effectiveness by WIB is studied under horizontal-rocking coupled loading in elastic half-space in the upper stiff-layer and lower soft-layer. The results show that the foundation of the stratification parameter and the characteristics of non-uniform have significant influence on the vibration isolation effect of the WIB, and the isolation vibration effectiveness of lower soft-layer is better than the upper stiff-layer.

A Semi-Analytical Model for the Simulation of the Isolation of the Vibration Due to a Harmonic Load Using Pile Rows Embedded in a Saturated Half-Space

The isolation of the vibration due to a harmonic vertical load using pile rows embedded in a saturated poroelastic half-space is investigated in this study. Using the fundamental solution for a circular patch load and Muki’s method, the second kind of Fredholm integral equations describing the dynamical interaction between the pile rows and the saturated poroelastic half-space are obtained. Numerical solution of the integral equations yields the dynamic response of the pile-half-space system. The vibration isolation effect of the pile rows is investigated via the proposed semi-analytical model. Numerical results indicate that stiffer piles have better isolation vibration effect than flexible piles. Moreover, the pile length and the spacing between neighboring piles in one pile row have significant influence on the isolation vibration effect of pile rows, while the influence of the spacing between neighboring pile rows is relatively smaller.