High-Frequency Vibration Analysis of Thin Plate Based on B-Spline Wavelet on Interval Finite Element Method

Author(s):  
Jia Geng ◽  
Xingwu Zhang ◽  
Xuefeng Chen ◽  
Xiaofeng Xue

For the dynamic analysis of thin plate bending problems, the Finite Element Methods (FEMs) are the most commonly used numerical techniques in engineering. However, due to the deficiency of low computing efficiency and accuracy, the FEMs can’t be directly used to effectively evaluate dynamic analysis of thin plate with high modal density within low-high frequency domain. In order to solve this problem, the Wavelet Finite Element Methods (WFEMs) has been introduced to solve the problem by improving the computing efficiency and accuracy in this paper. Due to the properties of multi-resolution, the WFEMs own excellently high computing efficiency and accuracy for structure analysis. Furthermore, for the destination of predicting dynamic response of thin plate within high frequency domain, this paper introduces the Multi-wavelet element method based on c1 type wavelet thin plate element and a new assembly procedure to significantly promote the calculating efficiency and accuracy which aim at breaking up the limitation of frequency domain when using the existing WFEMs and traditional FEMs. Besides, the numerical studies are applied to certify the validity of the method by predicting state response of thin plate within 0∼1000Hz based on a special numerical example with high modal density. According to the literature, the frequency domain between 0 to 1000Hz contains the low-high frequency domain aiming at the numerical example. The numerical results show excellent agreement with the reference solutions captured by FEM and analytical expressions respectively. Among these, it is noteworthy that the relative errors between the analytical solutions and numerical solution are less than 0.4% when the dynamic response involved with 1000 modes.

2006 ◽  
Vol 33 (2) ◽  
pp. 169-182 ◽  
Author(s):  
B F Sparling ◽  
L D Wegner

Both frequency- and time-domain methods have been employed in the dynamic analysis of guyed telecommunication masts subjected to turbulent winds. Although the probabilistic frequency-domain approach offers some advantages in terms of its relative ease of implementation and in the statistical reliability of wind load descriptions, the deterministic time-domain method permits a more realistic treatment of system nonlinearities. In this study, a numerical investigation was undertaken to compare frequency- and time-domain dynamic response predictions for a selected guyed mast in gusty winds. Two different analysis techniques were employed, with the frequency-domain calculations performed using response influence lines and the time-domain analyses carried out using a stiffness-based finite element model. Good agreement was observed in root-mean-square and peak dynamic response estimates after compensation was included for differences in turbulence intensity levels assumed in the two models. In general, natural frequencies and mode shapes were also similar.Key words: guyed mast, dynamic analysis, wind, turbulence, nonlinear behaviour, finite element analysis, cables, frequency domain, time domain.


2011 ◽  
Vol 189-193 ◽  
pp. 1914-1917
Author(s):  
Lin Ji

A key assumption of conventional Statistical Energy Analysis (SEA) theory is that, for two coupled subsystems, the transmitted power from one to another is proportional to the energy differences between the mode pairs of the two subsystems. Previous research has shown that such an assumption remains valid if each individual subsystem is of high modal density. This thus limits the successful applications of SEA theory mostly to the regime of high frequency vibration modeling. This paper argues that, under certain coupling conditions, conventional SEA can be extended to solve the mid-frequency vibration problems where systems may consist of both mode-dense and mode-spare subsystems, e.g. ribbed-plates.


1984 ◽  
Vol 106 (3) ◽  
pp. 270-275
Author(s):  
J. F. Loeber

In this paper, representation of the effects of incompressible fluid on the dynamic response of parallel beams in fluid-filled containers is developed using the concept of hydrodynamic mass. Using a two-step process, first the hydrodynamic mass matrix per unit (beam) length is derived using finite element methods with a thermal analogy. Second, this mass matrix is distributed in a consistent mass fashion along the beam lengths in a manner that accommodates three-dimensional beam bending plus torsion. The technique is illustrated by application to analysis of an experiment involving vibration of an array of four tubes in a fluid-filled cylinder.


1997 ◽  
Vol 119 (4) ◽  
pp. 831-833 ◽  
Author(s):  
Fan Zijie ◽  
Lu Bingheng ◽  
C. H. Ku

The main objective of this work is to predict the effect of distributed viscoelastic damping on the dynamic response of multilink flexible robot manipulators. A general approach, based on the principle of virtual work, is presented for the modeling of flexible robot arms with distributed viscoelastic damping. The finite element equations are developed, and a recurrence formulation for numerical integration of these equations is obtained. It is demonstrated, by a numerical example, that the viscoelastic damping treatments have a significant effect on the dynamic response of flexible robot manipulators.


2019 ◽  
Vol 17 (09) ◽  
pp. 1950060
Author(s):  
Tengfei Dai ◽  
Xia Jin ◽  
Huaze Yang ◽  
Tianran Lin ◽  
Yuantong Gu

Modeling and simulation of the acoustic response in enclosed cavities of a diesel engine are of great significance for optimal design of an engine to achieve a better acoustic performance. Nevertheless, the use of the traditional finite element method (FEM) for the mid to high frequency acoustic prediction is limited by the well-known numerical dispersion errors and the tedious preprocessing of the model. Smoothed finite element methods (SFEMs) proposed originally for solid mechanics have been employed for the modeling of acoustic problems in the low to medium frequency ranges whilst acoustic modeling in the mid to high frequency range remains untouched. This paper comprehensively investigates into the performance of SFEMs in modeling and simulation of mid to high frequency acoustic problems. It is shown that the mass-redistributed edge-based smoothed finite element method (MR-ES-FEM) can yield an excellent prediction result in the mid to high frequency range in terms of accuracy, efficiency and robustness. The MR-ES-FEM is also used to simulate sound propagation in a cylinder head chamber of a four-cylinder diesel engine to prove its effectiveness. The findings presented in this paper offer an in-depth insight for engineers to select suitable numerical methods for solving mid to high frequency acoustic problems in the design of diesel engines.


2010 ◽  
Vol 143-144 ◽  
pp. 1264-1269 ◽  
Author(s):  
Wen Hui Mo

Material properties, geometry parameters and applied loads are modeled as random variables. Sensitivity of linear vibration is formulated. If displacement vector is not sensitive to a parameter, we regard it as constant. If displacement vector is very sensitive to a parameter, designer should modify its datum and provide a rational tolerance. The numerical example demonstrates the proposed method. Stochastic finite element that does not analyze sensitivity is unreasonable.


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