Dynamic Analysis of Elastic Structures on Spreadsheet

2012 ◽  
Author(s):  
J.-M. Rambach
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Safety Assessment ◽  
Degrees Of Freedom ◽  
Vertical Plane ◽  
Design Stage ◽  
Margin Assessment ◽  
Sensitivity Studies ◽  
Stick Model

It is recalled the interest of modal analysis of heavy structures on stick model with reduced number of degrees-of-freedom (DOF), at every age of the structure: at the presizing stage, at the design stage, for assessing the results given by large tridimensional Finite Element (FE) models, and at every further seismic review (Seismic Margin Assessment studies, Seismic Probabilistic Safety Assessment studies). This article indicates a practical means for a simple programing of a modal analysis based FE code on spreadsheet able to handle up to 50 DOF. The beams, of Timoshenko’s type, are supposed moving along a vertical plane, with 2 DOF per node: the horizontal translational DOF and the rotational DOF around the horizontal axis perpendicular to the vertical plane. The analysis follows the classical steps of any FE code. The programing of such dynamic modal analysis on a spreadsheet is besides quite easy and provides a very convenient tool i) for the intimate understanding of the dynamic behavior of structures ii) for any accurate modal analysis and iii) for any sensitivity studies.

Selection of Degrees of Freedom for Dynamic Analysis

1987 ◽  
Vol 109 (1) ◽  
pp. 65-69 ◽  
Author(s):  
K. W. Matta
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Degrees Of Freedom ◽  
General Purpose ◽  
Component Mode Synthesis ◽  
Complex Structures ◽  
Large Complex ◽  
Static Condensation ◽  
Basis Vectors ◽  
Selection Of

A technique for the selection of dynamic degrees of freedom (DDOF) of large, complex structures for dynamic analysis is described and the formulation of Ritz basis vectors for static condensation and component mode synthesis is presented. Generally, the selection of DDOF is left to the judgment of engineers. For large, complex structures, however, a danger of poor or improper selection of DDOF exists. An improper selection may result in singularity of the eigenvalue problem, or in missing some of the lower frequencies. This technique can be used to select the DDOF to reduce the size of large eigenproblems and to select the DDOF to eliminate the singularities of the assembled eigenproblem of component mode synthesis. The execution of this technique is discussed in this paper. Examples are given for using this technique in conjunction with a general purpose finite element computer program GENSAM[1].

The Finite Element Analysis and Comparison of Wind Turbine Tower under Static Wind Load and Fluctuating Wind Load

2013 ◽  
Vol 446-447 ◽  
pp. 733-737
Author(s):  
Chi Chen ◽  
Hao Yuan Chen ◽  
Tian Lu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Wind Turbine ◽  
Modal Analysis ◽  
Large Scale ◽  
Wind Load ◽  
Element Analysis ◽  
Finite Element Software ◽  
Wind Turbine Tower ◽  
Fluctuating Wind

In this paper, a 1.5 MW wind turbine tower in Dali, Yunnan Province is used as the research object, using large-scale finite element software Ansys to carry on the dynamic analysis. These natural frequencies and natural vibration type of the first five of tower are obtained by modal analysis and are compared with natural frequency to determine whether the resonance occurs. Based on the modal analysis, the results of the transient dynamic analysis are obtained from the tower, which is loaded by the static wind load and fluctuating wind load in two different forms. By comparing the different results, it provides the basis for the dynamic design of wind turbine tower.

Modeling and Modal Analysis of Less-Teeth Gear Shaft

2013 ◽  
Vol 385-386 ◽  
pp. 192-195
Author(s):  
Dong Sheng Zhang ◽  
Jian Jun Zhang
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Helix Angle ◽  
Mode Shapes ◽  
Contact Ratio ◽  
Finite Element Software ◽  
Meshing Characteristics ◽  
Dynamic Meshing ◽  
Ansys Workbench

As the less-teeth gear has the less-teeth, the bigger helix angle and the more contact ratio etc. The research of dynamic meshing characteristics makes focus, and modal analysis is the basis of dynamic analysis. In order to get the modal analysis characteristics: firstly the parametric solid modeling is realized through the software of MATLAB and PRO/E; secondly multistage inherent frequencies and mode shapes are achieved by the finite element software of ANSYS Workbench.

Output-Only Modal Analysis of an Internal Unreachable Module Embedded in a Space Electronic Equipment

2012 ◽  
Author(s):  
Lassaad Ben Fekih ◽  
Georges Kouroussis ◽  
David Wattiaux ◽  
Olivier Verlinden ◽  
Christophe De Fruytier
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Degrees Of Freedom ◽  
Transverse Direction ◽  
Mode Shapes ◽  
Fe Model ◽  
Fe Method ◽  
Numeric Model ◽  
Stiffness Matrices ◽  
Output Only

An approach is proposed to identify the modal properties of a subsystem made up of an arbitrary chosen inner module of embedded space equipment. An experimental modal analysis was carried out along the equipment transverse direction with references taken onto its outer housing. In parallel, a numerical model using the finite element (FE) method was developed to correlate with the measured results. A static Guyan reduction has led to a set of master degrees of freedom in which the experimental mode shapes were expanded. An updating technique consisting in minimizing the dynamic residual induced by the FE model and the measurements has been investigated. A last verification has consisted in solving the numeric model composed of the new mass and stiffness matrices obtained by means of a minimization of the error in the constitutive equation method.

scholarly journals Modal Analysis of a Discrete System in the Form of a Rocket Launcher Installed on a Motor Vehicle

2016 ◽  
Vol 7 (3) ◽  
pp. 47-58
Author(s):  
Zbigniew DZIOPA ◽  
Maciej NYCKOWSKI
Keyword(s):  
Modal Analysis ◽  
Degrees Of Freedom ◽  
Motor Vehicle ◽  
Vertical Plane ◽  
Amplitude Distribution ◽  
Analytical Form ◽  
Distribution Coefficients ◽  
Characteristic Values ◽  
Definition Of ◽  
Second Order Equations

A discrete model of an unguided rocket missile launcher installed on a motor vehicle was developed on the basis of a real assembly. The model is simplified to a vertical plane; it has four degrees of freedom and is adapted for a modal analysis. A mathematical model was derived using the variational method on the basis of the assumed physical model. Analytical dependencies in the form of adjoint second order equations taking ordinary derivatives describe the dynamics of the considered system. The equations describing the autonomous motion of the system provided a definition of the generalized eigenvalue problem and the age equation forming the basis of the characteristic values. An analytical form of particular integrals was assumed for equations describing proper vibrations and the amplitude distribution coefficients were calculated. Four forms of proper vibrations of the considered system were obtained on the basis of the determined eigenvectors.

scholarly journals Finite Element Analysis of F1 Halo Safety Structure

2021 ◽  
Vol 9 (12) ◽  
pp. 1686-1689
Author(s):  
Manas Metar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Static Analysis ◽  
Element Analysis ◽  
Permissible Levels

Abstract: The Federation Internationale de L’Autobile (FIA) has been working on improving safety of drivers in open wheel racing series. Numerous incidents caused serious impacts on drivers’ lives. The car-to-car collision, car to environment collision and injuries due to flying debris are common threats to these drivers. In 2016 the introduction of Halo surrounding the cockpit was appreciated by the FIA. The following study includes the analysis of this Halo system using Finite Element Analysis (FEA). The dynamic, static and modal analysis is carried out with the help of Simscale software and the results obtained showed the values under permissible levels. Keywords: Finite Element Analysis, Static Analysis, Modal Analysis, Dynamic Analysis, F1 Halo, FIA.

Analysis of Impeller Vibration in Radial Compressors

1986 ◽  
Author(s):  
J. Wachter
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Dynamic Behaviour ◽  
Modal Parameters ◽  
Centrifugal Impeller ◽  
Experimental Investigations ◽  
Finite Element Program ◽  
Element Program ◽  
Detailed Application

The prediction of the dynamic behaviour of the impellers is of considerable importance in the design of turbomachines. The excitation possibilities of the radial impellers by the forces or imposed displacements are various and an appreciation of the life of radial impellers is strongly bounded to an accurate dynamic analysis. Therefore, it is necessary to analyze them in order to improve the geometry or modify the design. In order to better understand and explain the dynamic behaviour of impellers, a series of impeller models with various numbers of blades of radial or tangential extention have been examined. Because of complexity of analytical analysis shown in earlier works, the eigenfrequencies and modes of the impellers were evaluated using a Finite Element program. Interferometric holography served as a means to visualize the dynamic behaviour of the impellers. An experimental modal analysis was used to identify the modal parameters. A detailed application of these methods to an actual centrifugal impeller was also reported along with theoretical and experimental investigations on the impeller models.

Dynamic Analysis of Steelwork of the Small Capacity and Economic Mechanical Parking System

2012 ◽  
Vol 252 ◽  
pp. 158-161
Author(s):  
Hai Ying Li ◽  
Hua Liang Wu ◽  
Xiao Hong Chen ◽  
Sheng Jian Xie
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Modal Analysis ◽  
Theoretical Basis ◽  
Analysis Model ◽  
Full Load ◽  
Finite Element Software ◽  
Parking System ◽  
Small Capacity

By using finite element software, the paper establishes the steelwork analysis model of the small capacity and economic mechanical parking system and provides the modal analysis of steelwork in both cases of no-load and full load. In this paper, it provides a theoretical basis for the design of mechanical parking system steelwork.

Transient Dynamic Analysis of Maglev Linear Feed Unit

2011 ◽  
Vol 317-319 ◽  
pp. 405-409
Author(s):  
An Dong Jiang ◽  
Jiang Jin ◽  
Su Yang Ma ◽  
Zheng Peng Xia ◽  
Ping Liao
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Magnetic Levitation ◽  
Element Model ◽  
Design Stage ◽  
Transient Dynamic Analysis ◽  
Element Analysis ◽  
Forecast Performance ◽  
Transient Dynamic ◽  
Feed Unit

Abstract. The magnetic levitation linear feed unit is a new type of machine features. In machining, the tool and workpiece interaction force will be delivered to the table and make the deformation, resulting in processing errors of machine tools, machining of precision and surface quality. In this paper we established three-dimensional finite element model of the table of feed unit, use the finite element analysis software ANSYS to analysis of the transient dynamic analysis of the pre-designed table and improve the structure of the table at the design stage and forecast performance of the table and provide a theoretical basis for structure optimization.

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