scholarly journals Finite Element Calculation with Experimental Verification for a Free-Flooded Transducer Based on Fluid Cavity Structure

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 3128
Author(s):  
Zhengyao He ◽  
Geng Chen ◽  
Yun Wang ◽  
Kan Zhang ◽  
Wenqiang Tian

A free-flooded transducer that couples the vibration of a longitudinal vibration transducer and the fluid cavity of an aluminum ring was investigated. Given the transducer is based on a fluid cavity structure and has no air cavity, it can resist high hydrostatic pressure when working underwater, which is suitable for application in the deep sea. At first, the structure and working principle of the transducer were introduced. Then, the axisymmetric finite element model of the transducer was established; and the transmitting voltage response, admittance, and radiation directivity of the transducer were simulated using the finite element method. According to the size of the finite element model, a prototype of the transducer was designed and fabricated, and the electro-acoustic performance of the prototype was measured in an anechoic water tank. The experimental results were consistent with the simulation results and showed a good performance of the transducer. Finally, the improvement of the radiation directivity of the transducer by the optimal design of the free-flooded aluminum ring was obtained using the finite element method and verified by experiments.

1992 ◽  
Vol 20 (4) ◽  
pp. 212-229 ◽  
Author(s):  
H. Murakoshi ◽  
H. Ide ◽  
S. Nishihata

Abstract A vehicle sometimes drifts in a straight lane. This is caused by wind, road contour, suspension alignment, and tire properties. In this paper, characteristic tire properties which affect vehicle pull are defined and analyzed by the finite element method. The effect of tire construction and tread pattern on these characteristics are discussed.


Author(s):  
M. K. Sarwar ◽  
A. A. Shabana ◽  
Toshikazu Nakanishi

Abstract The objective of this study is to develop a design procedure that integrates multibody techniques, the finite element method, and experimental modal analysis techniques. Multibody techniques and the finite element method are first used to develop and numerically test the performance of the proposed design. Based on this computer analysis, a prototype model can be built. The vibration modal parameters of this model can be determined experimentally and used with general purpose multibody computer programs to evaluate the performance of the design. The obtained numerical results can be compared with the results obtained previously using multibody techniques and the finite element method. Adjustments can then be made in the finite element description in order to obtain a more realistic model that compares well with the experimental data. Using the more realistic finite element model, design modifications can be made in order to improve the performance of the design model. The use of the design methodology proposed in this paper is demonstrated using a flexible tracked vehicle model that consists of fifty four interconnected bodies. In this model, the nonlinear contact forces that describe the interaction between the track links and the vehicle components and the ground are developed. The nonlinear dynamic equations of the vehicle are developed in terms of a coupled set of reference and chassis elastic modal coordinates. The flexibility of the chassis of the tracked vehicle is described using the finite element method and experimentally identified modal parameters. The results obtained using the finite element model are compared with the results obtained using experimentally identified modal parameters.


2012 ◽  
Vol 516-517 ◽  
pp. 1584-1589
Author(s):  
Yuan Cheng ◽  
Xue Fan Wang

For Brushless Doubly-fed Machine(BDFM), the main feature of field is that there are two kinds of magnetic fields differing in pole number in the machine’s iron circuit and the two fields have the same order of magnitude. Hence, it is difficult to calculate the machine’s performance accurately using conventional analytic method. In this paper, the author constructed one finite-element model of BDFM, and analyzed the machine’s performance using transient solver. The author also compared the finite-element method with experiment and conventional analytic method. Because taking into account the saturation, the results of finite-element method are closer to the measurements than that of conventional analytic method. The validity of model is verified.


2021 ◽  
Vol 9 (9) ◽  
pp. 956
Author(s):  
Yi-Qing Zhou ◽  
Wen-Yu Luo

The finite element method is a popular numerical method in engineering applications. However, there is not enough research about the finite element method in underwater sound propagation. The finite element method can achieve high accuracy and great universality. We aim to develop a three-dimensional finite element model focusing on underwater sound propagation. As the foundation of this research, we put forward a finite element model in the Cartesian coordinate system for a sound field in a two-dimensional environment. We firstly introduce the details of the implementation of the finite element model, as well as different methods to deal with boundary conditions and a comparison of these methods. Then, we use four-node quadrilateral elements to discretize the physical domain, and apply the perfectly matched layer approach to deal with the infinite region. After that, we apply the model to underwater sound propagation problems including the wedge-shaped waveguide benchmark problem and the problem where the bathymetry consists of a sloping region and a flat region. The results by the presented finite element model are in excellent agreement with analytical and benchmark numerical solutions, implying that the presented finite element model is able to solve complex two-dimensional underwater sound propagation problems accurately. In the end, we compare the finite element model with the popular normal mode model KRAKEN by calculating sound fields in Pekeris waveguides, and find that the finite element model has better universality than KRAKEN.


1982 ◽  
Vol 104 (1) ◽  
pp. 84-90 ◽  
Author(s):  
M. C. Moyer ◽  
K. M. Marshek

This paper presents a procedure on the finite element method for analyzing a bolted flange connector and compares this method with three traditional approaches. The finite element method considers such effects as flange interface separation, nonlinear and nonconstant flange stiffness, and bolt bending. A comparison of the finite element model with the three traditional methods (each employs a formula for flange stiffness) shows a fairly close correlation for total bolt force versus applied load, but a wide discrepancy for maximum bolt stress versus applied load. The discrepancy between the finite element model analysis and the three other methods (empirical by Weiss and Wallner, truncated conical area by Roetscher, and the classical hollow cylinder approach) can be attributed to the change in flange stiffness during separation and the occurrence of bolt bending. The selected method of analysis was shown to significantly affect the results of a bolt fatigue analysis, but was shown to have little effect on a static analysis. In offshore applications, the environment creates dynamic stresses which make a fatigue analysis essential for long-term safety.


Author(s):  
J. Poirier ◽  
P. Radziszewski

The natural frequencies of circular saws limit the operating speeds of the saws. Current industry methods of increasing natural frequency include pretensioning, where plastic deformation is induced into the saw. To better model the saw, the finite element model is compared to current software for steel saws; C-SAW, a software program that calculates frequencies for stiffened circular saws. Using C-SAW and the finite element method the results are compared and the finite element method is validated for steel saws.


2020 ◽  
Vol 299 ◽  
pp. 1184-1189
Author(s):  
V.V. Zhukov ◽  
Anton V. Eremin ◽  
D.V. Stepanec

In this article, the object of study is a three–layer honeycomb panel with fixing elements (FE), which are used for transporting the panel, and fixing it to the spacecraft. The goal of the work is to determine experimentally the load carrying capacity of the fixing elements under various types of loading, to determine the load carrying capacity of the honeycomb panel of the spacecraft at fixing points and further comparison of the experimental results with the finite element method results calculated by MSC.Patran / Nastran. A method for conducting static tests of fixing elements of a spacecraft honeycomb panel under an external load is described, a description of computer technology of a finite–element solution to the problem of static strength of a honeycomb panel structure in the MSC.Patran environment is presented, and a finite–element model of a honeycomb panel is designed. An assessment of the strength of a three–layer structure at fixing points was carried out, followed by validation of the finite–element model of a honeycomb panel. On the basis of the validated model, the evaluation of the strength of the honeycomb structure was carried out; based on results obtained, the conclusion has been made about the convergence of the results by the finite element method with the results obtained during the experiment.


Author(s):  
Yong Bai ◽  
Zhimeng Yu

Pipeline on-bottom stability is one of the sophisticated problems in subsea pipeline design procedure. Due to the uncertainty of the pipe-soil interaction and environment loads, including wave, current, or earthquake, etc., it is classified as the typical nonlinear problem. The Finite Element Method is introduced into pipeline engineering several years ago. More and more special engineering software such as AGA, PONDUS are available in market. However, when doing a project, some abnormal data was found when compared the DnV calculation results and AGA. In order to know the behavior of pipeline on seabed under wave and current load, finite element method – ABAQUS is introduced to do this analysis. The ABAQUS/explicit is used to simulate 600s pipeline dynamic response. The pipeline is supposed to be exposed on seabed and the selected seabed model is large enough to avoid the edge effect. ABAQUS calculation results are compared with the requirements in DnV rules to verify the validity of finite element model.


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Jianwei Li ◽  
Jinghua Wang ◽  
Leian Zhang ◽  
Xuemei Huang ◽  
Yongfeng Yu

Delamination is detrimental to the composite materials, and it may occur in the manufacturing process of the unidirectional laminate of the spar cap in wind turbine blades. This paper studies the effect of different delamination defects on the strength of the unidirectional laminate. The finite element model of laminate with different delamination areas and delamination heights is established using solid elements. The eigenvalues of laminates have different parameters calculated based on the finite element method. The final coupon test is used to verify the conclusions of simulation results. The finite element method presented in this study shows excellent capabilities to predict the buckling behavior of the laminate. The buckling eigenvalue of tested laminate is negatively correlated with the delamination area and positively correlated with the delamination height under the edgewise load. The S11, which is too high at the boundary of the delamination region, plays a significant role in buckling failure. It has a particular reference value for testing the laminate of blade both in theory and practice.


2014 ◽  
Vol 984-985 ◽  
pp. 431-437
Author(s):  
Vijaykumar Hiremath ◽  
Girija Bidarimath ◽  
Basavaraj Endigeri

In this paper finite element model of steel dental bracket is generated along with bonding agent, enamel & stress analysis is carried out on the bracket for different loading conditions. Three dimensional finite element model developed are constrained with boundary condition that resembles to the reality. The Vonmisses stress is recorded for each loading conditions and compared with experimental results. The experimental work for 60 samples were carried out on Universal testing machine at material testing laboratory, Basaveshwar Engineering College, Bagalkot. It is found from FEM results that the shear bonding strength for different loadings from 60 N to 80 N varies from 7.276 N/mm2 to 9.7N/mm2, which are closer to experimental values with acceptable error. The study reveals that Finite Element Method can be used as a strong tool to analyze the dental bracket and study different parameters to improve its performance and to avoid time and cost required for experimentation.


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