157 Nonlinear Vibration Analysis of a Beam with Breathing Cracks : Finite Element Analysis Based on the Mixed Variational Principle

2006 ◽  
Vol 2006 (0) ◽  
pp. _157-1_-_157-6_
Author(s):  
Keisuke KAMIYA ◽  
Terumitsu YOSHINAGA
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Variational Principle ◽  
Nonlinear Vibration ◽  
Vibration Analysis ◽  
Element Analysis ◽  
Mixed Variational Principle

Application of ESPI in the Vibration Analysis of Turbine Blading

1995 ◽  
Author(s):  
Robert X. Wang ◽  
Graham M. Chapman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Analysis ◽  
Speckle Pattern ◽  
Vibration Measurement ◽  
Simplified Model ◽  
Electronic Speckle Pattern Interferometry ◽  
Coupled Modes ◽  
Element Analysis ◽  
Turbine Blading

Abstract This paper reports on the application of Electronic Speckle Pattern Interferometry (ESPI) technique in vibration measurement of turbine blading. Using the time-averaged mode of ESPI, the first six modes of a turbocharger blade with airfoil profile were identified. The effect of the complicated profile of the blade was established by studying simplified model blades. Coupled modes were identified and successfully separated. Experimental results are compared with those obtained using finite element analysis.

Investigation of stiffness of small wind turbine blade based on vibration analysis technique

2019 ◽  
Vol 44 (1) ◽  
pp. 49-59
Author(s):  
Nilesh Chandgude ◽  
Nitin Gadhave ◽  
Ganesh Taware ◽  
Nitin Patil
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Wind Turbine ◽  
Natural Frequency ◽  
Vibration Analysis ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Element Analysis ◽  
Finite Element Software ◽  
Small Wind Turbine

In this article, three small wind turbine blades of different materials were manufactured. Finite element analysis was carried out using finite element software ANSYS 14.5 on modeled blades of National Advisory Committee for Aeronautics 4412 airfoil profile. From finite element analysis, first, two flap-wise natural frequencies and mode shapes of three different blades are obtained. Experimental vibration analysis of manufactured blades was carried out using fast Fourier transform analyzer to find the first two flap-wise natural frequencies. Finally, the results obtained from the finite element analysis and experimental test of three blades are compared. Based on vibration analysis, we found that the natural frequency of glass fiber reinforced plastic blade reinforced with aluminum sheet metal (small) strips increases compared with the remaining blades. An increase in the natural frequency indicates an increase in the stiffness of blade.

scholarly journals What's that Noise?

2011 ◽  
Vol 133 (10) ◽  
pp. 44-45
Author(s):  
Lynn Manning
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Automotive Industry ◽  
Vibration Analysis ◽  
Instrument Panel ◽  
Analysis Method ◽  
Element Analysis ◽  
Noise And Vibration ◽  
To Come ◽  
Testing Company

This article focuses on various features of a finite element analysis (FEA) program designed by IDIADA, a Barcelona-based company providing design, engineering, testing, and homologation services to the automotive industry. The program has been designed as a solution to the problem of squeaks and rattles in an automobile. FEA software used by engineers from automotive testing company IDIADA detects potential automotive noise. The company uses Abaqus Unified Finite Element Analysis from Dassault Systèmes’ brand Simulia. The team delivered a paper at the Simulia Customer Conference in Barcelona in May 2011 to present the latest improvements in their methodology, applied to rattle in a car instrument panel and correlated with real-world testing. Research has shown that a standard noise-and-vibration analysis method alone can’t model, or predict, the contact that will result in a rattle. The engineers need to come up with a simulation that can accommodate both frequency for noise and vibration and contact for squeak and rattle.

Finite Element Analysis (FEA) of Honeycomb Sandwich Panel for Continuum Properties Evaluation and Core Height Influence on the Dynamic Behavior

2011 ◽  
Vol 326 ◽  
pp. 1-10 ◽  
Author(s):  
Hammad Rahman ◽  
Rehan Jamshed ◽  
Haris Hameed ◽  
Sajid Raza
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytical Solution ◽  
Vibration Analysis ◽  
Sandwich Structure ◽  
Sandwich Panel ◽  
Fe Analysis ◽  
Element Analysis ◽  
Honeycomb Sandwich ◽  
Core Height

Finite element analysis of honeycomb sandwich panel has been performed by modeling the structure through three different approaches. Continuum properties are calculated through analytical solution and verified through FE analysis of bare core. In addition to that the thickness of core has also been varied in all the three approaches in order to study its effect on vibration analysis of sandwich structure.

Parametric Variational Principle for Bi-Modulus Materials and Its Application to Nacreous Bio-Composites

2016 ◽  
Vol 08 (06) ◽  
pp. 1650082 ◽  
Author(s):  
Liang Zhang ◽  
Huiting Zhang ◽  
Jian Wu ◽  
Bo Yan ◽  
Mengkai Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Variational Principle ◽  
Principal Stress ◽  
Stress Strain ◽  
Element Analysis ◽  
Parametric Variational Principle ◽  
Strain Relation ◽  
Stress Strain Relation ◽  
Nonlinear Stress

Bi-modulus materials have different moduli in tension and compression and the stress–strain relation depends on principal stress that is unknown before displacement is determined. Establishment of variational principle is important for mechanical analysis of materials. First, parametric variational principle (PVP) is proposed for static analysis of bi-modulus materials and structures. A parametric variable indicating state of principal stress is included in the potential energy formulation and the nonlinear stress–strain relation is evolved into a linear complementarity constraint. Convergence of finite element analysis is thus improved. Then the proposed variational principle is extended to a dynamic problem and the dynamic equation can be derived based on Hamilton’s principle. Finite element analysis of nacreous bio-composites is performed, in which a unilateral contact behavior between two hard mineral bricks is modeled using the bi-modulus stress–strain relation. Effective modulus of composites can be determined numerically and stress mechanism of “tension–shear chain” in nacre is revealed. A delayed effect on stress propagation is found around the “gaps” between mineral bricks, when a tension force is loaded to nacreous bio-composites dynamically.

scholarly journals Dynamic Analysis of Folded Low Shells by Using Finite Element Analysis

2020 ◽  
pp. 94-103
Author(s):  
Emmanuel E. T. Olodo ◽  
Georges Adjibola A. Ale ◽  
Edmond Codjo Adjovi ◽  
Antoine Vianou
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Variational Principle ◽  
Harmonic Analysis ◽  
Forced Vibrations ◽  
Internal Damping ◽  
Element Analysis ◽  
Dynamic Stresses ◽  
Element Algorithm ◽  
Calculation Code

Aims: This work is devoted to the development of a finite element algorithm for solving problem in forced vibrations of folded low shells. Methodology: The differential equations for harmonic analysis are obtained from the Lagrange variational principle. Description of the dynamic behavior is made by the structure discretization into a system of curvilinear iso-parametric finite elements used in modal analysis. The method is implemented by a calculation code on a square-plane folded shell model withnumber of crease edges in both directions k=l=3. Results: Displacement amplitudesare obtained by decomposition into vibration eigenforms. The maximum values of dynamic stresses are determined taking into account the shell's support conditions.The results of the harmonic analysis show thatimprovement in frequency characteristics and reduction of stresses in the folded shell depend on the constructive and internal damping of the structureand the increase in the number of fold edges k and l in both directions for examplebecause this contributes to decrease in the forced vibration amplitudes.

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