scholarly journals Hermitian Mindlin Plate Wavelet Finite Element Method for Load Identification

2016 ◽  
Vol 2016 ◽  
pp. 1-24
Author(s):  
Xiaofeng Xue ◽  
Xuefeng Chen ◽  
Xingwu Zhang ◽  
Baijie Qiao ◽  
Jia Geng
Keyword(s):  
Finite Element ◽  
Spline Interpolation ◽  
Cubic Spline ◽  
Mindlin Plate ◽  
Load Identification ◽  
Plate Element ◽  
Wavelet Finite Element Method ◽  
The Time Domain ◽  
Wavelets On The Interval ◽  
Value Decomposition

A new Hermitian Mindlin plate wavelet element is proposed. The two-dimensional Hermitian cubic spline interpolation wavelet is substituted into finite element functions to construct frequency response function (FRF). It uses a system’s FRF and response spectrums to calculate load spectrums and then derives loads in the time domain via the inverse fast Fourier transform. By simulating different excitation cases, Hermitian cubic spline wavelets on the interval (HCSWI) finite elements are used to reverse load identification in the Mindlin plate. The singular value decomposition (SVD) method is adopted to solve the ill-posed inverse problem. Compared with ANSYS results, HCSWI Mindlin plate element can accurately identify the applied load. Numerical results show that the algorithm of HCSWI Mindlin plate element is effective. The accuracy of HCSWI can be verified by comparing the FRF of HCSWI and ANSYS elements with the experiment data. The experiment proves that the load identification of HCSWI Mindlin plate is effective and precise by using the FRF and response spectrums to calculate the loads.

Coupled Analysis of Structural–Acoustic Problems Using the Cell-Based Smoothed Three-Node Mindlin Plate Element

2016 ◽  
Vol 13 (02) ◽  
pp. 1640007 ◽  
Author(s):  
Z. X. Gong ◽  
Y. B. Chai ◽  
W. Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Solid Mechanics ◽  
Mindlin Plate ◽  
Coupled Analysis ◽  
Plate Element ◽  
Fem Model ◽  
The Face ◽  
Smoothed Finite Element Method ◽  
Element Method

The cell-based smoothed finite element method (CS-FEM) using the original three-node Mindlin plate element (MIN3) has recently established competitive advantages for analysis of solid mechanics problems. The three-node configuration of the MIN3 is achieved from the initial, complete quadratic deflection via ‘continuous’ shear edge constraints. In this paper, the proposed CS-FEM-MIN3 is firstly combined with the face-based smoothed finite element method (FS-FEM) to extend the range of application to analyze acoustic fluid–structure interaction problems. As both the CS-FEM and FS-FEM are based on the linear equations, the coupled method is only effective for linear problems. The cell-based smoothed operations are implemented over the two-dimensional (2D) structure domain discretized by triangular elements, while the face-based operations are implemented over the three-dimensional (3D) fluid domain discretized by tetrahedral elements. The gradient smoothing technique can properly soften the stiffness which is overly stiff in the standard FEM model. As a result, the solution accuracy of the coupled system can be significantly improved. Several superior properties of the coupled CS-FEM-MIN3/FS-FEM model are illustrated through a number of numerical examples.

scholarly journals A Stochastic Wavelet Finite Element Method for 1D and 2D Structures Analysis

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Xingwu Zhang ◽  
Xuefeng Chen ◽  
Zhibo Yang ◽  
Bing Li ◽  
Zhengjia He
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Polynomial Interpolation ◽  
Virtual Work ◽  
Structural Response ◽  
Mindlin Plate ◽  
Stochastic Finite Element ◽  
Wavelet Finite Element Method ◽  
Rigid Frame ◽  
Element Method

A stochastic finite element method based on B-spline wavelet on the interval (BSWI-SFEM) is presented for static analysis of 1D and 2D structures in this paper. Instead of conventional polynomial interpolation, the scaling functions of BSWI are employed to construct the displacement field. By means of virtual work principle and BSWI, the wavelet finite elements of beam, plate, and plane rigid frame are obtained. Combining the Monte Carlo method and the constructed BSWI elements together, the BSWI-SFEM is formulated. The constructed BSWI-SFEM can deal with the problems of structural response uncertainty caused by the variability of the material properties, static load amplitudes, and so on. Taking the widely used Timoshenko beam, the Mindlin plate, and the plane rigid frame as examples, numerical results have demonstrated that the proposed method can give a higher accuracy and a better constringency than the conventional stochastic finite element methods.

Hybrid Least Squares Finite Element Methods for Reissner-Mindlin Plates

1999 ◽  
Author(s):  
Lonny L. Thompson ◽  
Yuhuan Tong
Keyword(s):  
Finite Element ◽  
Least Squares ◽  
Equations Of Motion ◽  
Generalized Least Squares ◽  
Dispersion Relations ◽  
Wave Number ◽  
Design Parameters ◽  
Mindlin Plate ◽  
Plate Element ◽  
State Equations

Abstract An assumed-stress hybrid 4-node plate element is developed based on the Hellinger-Reissner variational principle modified with a generalized least-squares operator for accurate vibration and wave propagation response of Reissner-Mindlin plates. The least-squares operator is proportional to a weighted integral of a differential operator acting on the residual of the steady-state equations of motion for Reissner-Mindlin plates. Through judicious selection of the design parameters inherent in the least-squares modification, this formulation provides a consistent framework for enhancing the accuracy of mixed Reissner-Mindlin plate elements that have no shear locking or spurious modes. Improved methods are designed such that the complex wave-number finite element dispersion relations closely match the analytical relations for all wave angle directions. For uniform meshes, optimal methods are designed to achieve zero dispersion error along given wave directions. Comparisons of finite element dispersion relations demonstrate the superiority of the new hybrid least-squares plate element over the underlying hybrid element, and standard Galerkin elements based on selectively reduced integration. Numerical experiments validate these conclusions.

Parametric Studies on Moving Axle Load Identification

2001 ◽  
Author(s):  
Ling Yu ◽  
Tommy H. T. Chan
Keyword(s):  
Time Domain ◽  
Time Domain Method ◽  
Identification Accuracy ◽  
Load Identification ◽  
System Parameters ◽  
Domain Method ◽  
Parametric Studies ◽  
The Time Domain ◽  
Value Decomposition ◽  
Pseudo Inverse

Abstract This study addresses the effects of various parameters on moving axle load identification when vehicles move across a bridge. Main emphases are placed on evaluation of two solutions, pseudo-inverse (PI) and Singular value decomposition (SVD) solutions, to an over-determined set of equations established under the time domain method (TDM) and frequency-time domain method (FTDM). The effects of vehicle-bridge system parameters and of measurement system parameters on the TDM and FTDM are also investigated. Assessment results based on experiments in laboratory show that the TDM is a better and non-sensitive method. The SVD technique can effectively improve identification accuracy when using TDM and FTDM particularly in the case of the FTDM.

A Deformation Analysis and Compensation Algorithm for Bracket Structure of Automatic Drill-Riveting System

2014 ◽  
Vol 912-914 ◽  
pp. 539-544 ◽  
Author(s):  
Yuan Yang ◽  
Zhong Qi Wang ◽  
Yong Gang Kang ◽  
Zheng Ping Chang
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Fe Simulation ◽  
Spline Interpolation ◽  
Cubic Spline ◽  
Deformation Analysis ◽  
Analytic Method ◽  
Simulation Data ◽  
Cubic Spline Interpolation ◽  
Envelope Surface

Since the bracket deformation caused by its deadweight is too large, and the riveting of aircraft panel is always over-tolerance, a new algorithm for analysis and compensation of bracket deformation is presented in this paper. The algorithm is formed by combining finite element (FE) simulation with analytic method, which is fit for different combinations of supporting plates of bracket system. The formula is constructed through cubic spline interpolation and envelope surface fitting according to the FE simulation data. Meanwhile, a corresponding compensation method is proposed. Finally, a numerical simulation example with the software of ABAQUS shows that the algorithm and its results are valid and feasible.

A REINTERPRETATION OF EMD BY CUBIC SPLINE INTERPOLATION

2011 ◽  
Vol 03 (04) ◽  
pp. 527-540 ◽  
Author(s):  
MINJEONG PARK ◽  
DONGHOH KIM ◽  
HEE-SEOK OH
Keyword(s):  
Empirical Mode Decomposition ◽  
Time Domain ◽  
Spline Interpolation ◽  
Cubic Spline ◽  
Data Driven ◽  
Constant Frequency ◽  
Cubic Spline Interpolation ◽  
Mode Decomposition ◽  
The Time Domain ◽  
Theoretical Results

Empirical mode decomposition (EMD) is a data-driven technique that decomposes a signal into several zero-mean oscillatory waveforms according to the levels of oscillation. Most of the studies on EMD have focused on its use as an empirical tool. Recently, Rilling and Flandrin, [2008] studied theoretical aspects of EMD with extensive simulations, which allow a better understanding of the method. However, their theoretical results have been obtained by considering constraints on the signal such as equally spaced extrema and constant frequency. The present study investigates the theoretical properties of EMD using cubic spline interpolation under more general conditions on the signal. This study also theoretically supports modified EMD procedures in Kopsinis and Mclaughlin, [2008] and developed for improving the conventional EMD. Furthermore, all analyses are preformed in the time domain where EMD actually operates; therefore, the principle of EMD can be visually and directly captured, which is useful in interpreting EMD as a detection procedure of hidden components.

SHEAR STRAIN SAMPLING POINTS OF PLATE ELEMENT FROM DESIRABLE DISPLACEMENT FIELDS AND MIXED FINITE ELEMENTS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Teerapon Kowsuwan ◽  
Vanissorn Vimonsatit
Keyword(s):  
Finite Element ◽  
Plate Theory ◽  
Mixed Finite Element ◽  
High Order ◽  
Mindlin Plate ◽  
Transverse Displacement ◽  
Plate Element ◽  
Element Discretization ◽  
Assumed Strain ◽  
Sampling Points

A newly developed four-node bilinear plate element based on linked interpolation and Desirable Displacement Field (DDF) concept is formulated for the analysis of general plate problems. The proposed element is formulated on a mixed finite element for Reissner-mindlin plate theory and transverse displacement is linked to the rotation degree of freedom to ensure high-order interpolation capacity. By assumed strain method, the DDF is introduced for the investigation of strain sampling points. A high order polynomial for transverse displacement with linking shape function is used in finite element discretization to provide a better solution for the plate problems. A number of commonly selected problems will be tested using the present element to compare with other element models in the open literature to assess their relative convergence and accuracy.

Sign in / Sign up

Export Citation Format

Share Document