scholarly journals Research on the Cascade-Connected Transducer with Multi-Segment Used in the Acoustic Telemetry System while Drilling

Micromachines ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 712
Author(s):  
Duo Teng
Keyword(s):  
Finite Element ◽  
High Power ◽  
Acoustic Telemetry ◽  
Low Frequency ◽  
Mode Shapes ◽  
Telemetry System ◽  
The Finite Element Method ◽  
Electroacoustic Transducer ◽  
Flexural Vibrations ◽  
The Cross

The electroacoustic transducer with the performances of low frequency, small size, and high power is desired in the application of the acoustic telemetry system while drilling. In order to fulfill the severe requirements, a novel cascade-connected transducer with multi-segment is developed. The essential framework of such a transducer is to add the cross-beams in the multi-segment cascade-connected arrangement, based on the fundamental configuration of the longitudinal transducer. The flexural vibrations of cross-beams help the transducer to present the appropriate coupling between longitudinal and flexural vibrations, which provide many benefits in keeping the advantages of the longitudinal transducer and lowering the resonance frequency. It is the finite element method to be used for simulating the mode shapes of the cascade-connected transducer, especially the behavior of the cross-beams, and some performances of transducer are also predicted. Several prototypes of cascade-connected transducers with different segments are manufactured. Their related tests show a good agreement with the finite element simulations and analyses. Their characteristics of low frequency, small size, light weight, and high power are attractive for the transmitting or receiving application in the acoustic telemetry system while drilling.

A New Type of Electroacoustic Transducer Used for Downhole Acoustic Telemetry System

2013 ◽  
Vol 336-338 ◽  
pp. 286-289
Author(s):  
Xuan Chao Liu ◽  
Yan Xia He ◽  
Guo Hong Li
Keyword(s):  
High Power ◽  
Acoustic Telemetry ◽  
Petroleum Industry ◽  
Low Frequency ◽  
Telemetry System ◽  
Magnetostrictive Materials ◽  
Electroacoustic Transducer ◽  
Giant Magnetostrictive Materials ◽  
Frequency Output ◽  
New Type

The high power and low frequency electroacoustic transducer plays a very important role in the underground acoustic telemetry system used for petroleum industry. How to realize electroacoustic conversion technology with the giant magnetostrictive materials was studied in this paper. The principles and methods of how to design it were proposed and the experimental verification was achieved. Results show that the electroacoustic transducer based on giant magnetostrictive materials features high-power and low-frequency output, high conversion efficiency, high temperature resistance, and excellent performance. It can completely meet the needs of the downhole acoustic telemetry system.

Low Frequency Analysis of the Tracheo-Bronchia

2002 ◽  
Author(s):  
A. M. Al-Jumaily ◽  
N. Mago
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Frequency Analysis ◽  
Respiratory System ◽  
Future Development ◽  
Natural Frequencies ◽  
Low Frequency ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
Element Method

Theoretical natural frequencies and mode shapes for the tracheo-bronchia of the human respiratory system are determined using the finite element method. Radial modes, which are anticipated to be used for contraction relaxation, are identified. It is anticipated that these values will give the initiation for future development of non-traditional techniques of relieving respiratory system constrictions.

scholarly journals Modal Analysis of Orthotropic Thin Rectangular Plate Based on Analytical and Finite Element Approaches

2020 ◽  
Vol 30 (5-6) ◽  
pp. 217-225
Author(s):  
Samir Deghboudj ◽  
Wafia Boukhedena ◽  
Hamid Satha
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Rectangular Plate ◽  
Analytical Approach ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Thin Rectangular Plate ◽  
Good Agreement

The present work aims to carry out modal analysis of orthotropic thin rectangular plate to determine its natural frequencies and mode shapes by using analytical method based on Rayleigh-Ritz energy approach. To demonstrate the accuracy of this approach, the same plate is discritisated and analyzed using the finite element method. The natural and angular frequencies were computed and determined analytically and numerically by using ABAQUS finite element code. The convergency and accuracy of the numerical solution was examined. The effects of geometrical parameters and boundary conditions on vibrations are investigated. The results obtained showed a very good agreement between the analytical approach and the numerical simulations. Also, the paper presents simulations results of testing of the plate with passive vibration control.

Effect of Low-Frequency Vibration on Human Body in Standing Position Exposed to Railway Vehicle

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
Rajesh Govindan ◽  
Suraj Prakash Harsha
Keyword(s):  
Finite Element ◽  
Natural Frequency ◽  
Human Body ◽  
Low Frequency ◽  
Vertical Direction ◽  
Standing Position ◽  
Mode Shapes ◽  
Railway Vehicle ◽  
Lateral Direction ◽  
Low Frequency Vibration

In this paper, the dynamic characteristics of the human body were investigated by developing a 3-D finite element model based on 50th percentile anthropometric data for a 54 kg Indian male subject in standing position by considering human body segments as an ellipsoid. The finite element modal analysis is carried out to extract several low-frequency vibration modes and its vibration mode shapes were presented in this paper. The results show that the lowest natural frequency of the standing passenger model occurs in the fore-and-aft direction. The second natural frequency occurs in the lateral direction and the first order natural frequency of the standing passenger model in the vertical direction occurs at 5.379 Hz. The model will be helpful to predict the vibration response of human body under various vibration environment encounters in the railway vehicle.

Finite Element Analysis of Turbine Blades

1991 ◽  
Author(s):  
A. Carnero ◽  
J. Kubiak ◽  
A. López
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Radio Telemetry ◽  
Turbine Blades ◽  
Research Work ◽  
Mode Shapes ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Element Method

Abstract Frequent failures of long turbine blades forced an electrical utility to sponsor research work to find out the causes of the failures. One of the techniques applied in this work was finite element analysis. The paper presents an application of the finite element method for computation of the natural frequencies, steady-state and alternating stresses, deformations due to forces acting on the blades and modal shapes of the turbine long blade groups. Two stages, L-1 and L-0 of the low pressure part of a steam turbine, were analyzed. It has been postulated that the results of the FEM analysis of the blades groups would be complementary to those obtained from the radio telemetry test (which was carried out during operation of the turbine) for the purpose of blade group failure diagnosis. However, the results of the analysis show that the FEM results were decisive in blade failure identification (L-1 stage moving blades). The graphical post processor of the FEM code revealed that the first blade in the group was the one most protruding from the stage rotating plane, thus indicating that this blade was the most prone to erosion. This was confirmed in the inspection of the turbine. This finding showed why only the first blade in the group was cracked (erosion induced cracks). The mode shapes were also very helpful in identifying other types of cracks which affected other parts of the blades. It can be concluded that the finite element method is very useful for identification of very difficult cases of blade faults and indispensable for carrying out modifications to prevent future failures.

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