Vibration analysis of bi-stable composite cross-ply laminates using refined shape functions

2016 ◽  
Vol 51 (8) ◽  
pp. 1135-1148 ◽  
Author(s):  
A Firouzian-Nejad ◽  
S Ziaei-Rad ◽  
M Moore
Keyword(s):  
Finite Element ◽  
Composite Plates ◽  
Approximate Solutions ◽  
Element Model ◽  
Dynamic Responses ◽  
The Finite Element Method ◽  
Shape Functions ◽  
Design Modification ◽  
Qualitative And Quantitative ◽  
Applied Forces

In this article, static and dynamic responses of cross-ply bi-stable composite plates were studied. To accurately predict the natural frequencies and snap-through load, a set of higher order shape functions were proposed. In static analysis, the stable configurations, the deflection of corners, and the midpoint of the plate were calculated. For dynamic analysis, Hamilton’s principle is used to provide approximate solutions to the vibration problem under study. The responses of the plate under ramp and harmonic applied forces were determined, the effect of shape functions on the prediction of the first natural frequency of the plate and the required force for snap-through were investigated. A finite element model is also developed to study the static and vibration characteristics of bi-stable composite plate. The qualitative and quantitative comparisons between the finite element method results and those obtained from the present analysis are generally good and satisfactory. The developed analytical model can also be used for parametric study and further design modification.

Rolling Resistance Calculation Procedure Using the Finite Element Method

2019 ◽  
Vol 48 (3) ◽  
pp. 224-248
Author(s):  
Pablo N. Zitelli ◽  
Gabriel N. Curtosi ◽  
Jorge Kuster
Keyword(s):  
Finite Element ◽  
Energy Dissipation ◽  
Rolling Resistance ◽  
Element Model ◽  
The Finite Element Method ◽  
Temperature Changes ◽  
Rubber Compounds ◽  
Different Temperatures ◽  
Materials Used ◽  
Account Temperature

ABSTRACT Tire engineers are interested in predicting rolling resistance using tools such as numerical simulation and tests. When a car is driven along, its tires are subjected to repeated deformation, leading to energy dissipation as heat. Each point of a loaded tire is deformed as the tire completes a revolution. Most energy dissipation comes from the cyclic loading of the tire, which causes the rolling resistance in addition to the friction force in the contact patch between the tire and road. Rolling resistance mainly depends on the dissipation of viscoelastic energy of the rubber materials used to manufacture the tires. To obtain a good rolling resistance, the calculation method of the tire finite element model must take into account temperature changes. It is mandatory to calibrate all of the rubber compounds of the tire at different temperatures and strain frequencies. Linear viscoelasticity is used to model the materials properties and is found to be a suitable approach to tackle energy dissipation due to hysteresis for rolling resistance calculation.

Analysis of Hydroelectric Unit’s Upper Bracket Based on Test and FEM

2014 ◽  
Vol 721 ◽  
pp. 131-134
Author(s):  
Mi Mi Xia ◽  
Yong Gang Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Element Model ◽  
The Finite Element Method ◽  
Ansys Software ◽  
Element Analysis ◽  
Hydroelectric Unit ◽  
The Finite Element Analysis ◽  
Strain Rosette ◽  
The Finite Element Model

To research the load upper bracket of Francis hydroelectric unit, then established the finite-element model, and analyzed the structure stress of 7 operating condition points with the ANSYS software. By the strain rosette test, acquired the data of stress-strain in the area of stress concentration of the upper bracket. The inaccuracy was considered below 5% by analyzing the contradistinction between the finite-element analysis and the test, and match the engineering precision and the test was reliable. The finite-element method could be used to judge the stress of the upper bracket, and it could provide reference for the Structural optimization and improvement too.

scholarly journals Variational Methods for Glacier Mechanics Problems

1981 ◽  
Vol 27 (95) ◽  
pp. 19-24 ◽  
Author(s):  
Robert G. Oakberg
Keyword(s):  
Finite Element ◽  
Melting Point ◽  
Variational Principle ◽  
Finite Element Model ◽  
Related Problem ◽  
Cylindrical Channel ◽  
Direct Methods ◽  
Approximate Solutions ◽  
Element Model ◽  
Coordinate Functions

AbstractThe object of the research is to determine whether direct methods from the calculus of variations can provide convenient approximate solutions of complex problems in glacier mechanics. The Ritz technique is used to minimize an appropriate functional. Coordinate functions obtained from a finite-element model are combined with a coordinate function that is the solution of a related problem. The finite-element coordinate functions make localized adjustments to the related solution. Solutions of two sample problems are presented. An analysis of the closure of an intergranular vein in ice at the melting point is based upon a variational principle for velocities. An analysis of the flow of ice in a cylindrical channel is based upon a variational principle for stresses.

scholarly journals Numerical investigation of the effects of unsupported railway sleepers on train-induced environmental vibrations

2017 ◽  
Vol 36 (2) ◽  
pp. 160-176 ◽  
Author(s):  
Seyed-Ali Mosayebi ◽  
Morteza Esmaeili ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Two Dimensions ◽  
Railway Track ◽  
Sensitivity Analyses ◽  
Regression Equations ◽  
The Finite Element Method ◽  
Technical Literature ◽  
Support Force ◽  
Comparison Of The Results

Review of technical literature regarding to train-induced vibrations shows that the effects of unsupported railway sleepers on this issue have been less investigated. So, the present study was devoted to numerical investigations of the mentioned issue. In this regard, first the problem of longitudinal train–track dynamic interaction was simulated in two dimensions by using the finite element method and the developed model was validated through comparison of the results with those obtained by previous researchers. In the next stage, a series of sensitivity analyses were accomplished to account for the effects of value of gap beneath the unsupported sleeper(s) and the track support stiffness on increasing the sleeper displacement and track support force. Moreover, the raised sleeper support force was introduced as applied load to a two-dimensional plane strain finite element model of track in lateral section and consequently the train-induced vibrations were assessed. As a result, a series of regression equations were established between the peak particle velocity in the surrounding environment of railway track and the sleeper support stiffness for tracks without unsupported sleepers and with one and two unsupported sleepers.

Dynamic Responses Analysis of Permeable Breakwater Subjected to Random Waves

2014 ◽  
Vol 1061-1062 ◽  
pp. 809-812
Author(s):  
Hu Ping
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Dynamic Responses ◽  
Exceedance Probability ◽  
Random Waves ◽  
The Finite Element Method ◽  
Wave Load ◽  
Power Spectral ◽  
Density Analysis ◽  
Element Method

In this paper, based on the finite element method and ANSYS software, the dynamic responses of permeable breakwater under wave load response is analyzed and studied. Taking the method of combining modal analysis and power spectrum analysis research on dynamic response of breakwater in the frequency domain and the principal stress and displacement distribution of the structure in the exceedance probability of 0.7%. The results prove that the finite element method of power spectral density analysis can provide effective guidance for the actual engineering.

Separating the Contributions in Localization Methods: A Technique to Enhance Identification of Damping Related Parameters

1999 ◽  
Author(s):  
Hervé Algrain ◽  
Calogero Conti ◽  
Pierre Dehombreux
Keyword(s):  
Finite Element ◽  
Model Updating ◽  
Element Model ◽  
Dynamic Responses ◽  
Finite Element Model Updating ◽  
Global Localization ◽  
Localization Method ◽  
The Family ◽  
Family Based ◽  
The Stability

Abstract Finite Element Model Updating has for objective to increase the correlation between the experimental dynamic responses of a structure and the predictions from a model. Among different initial choices, these procedures need to establish a set of representative parameters to be updated in which some are in real error and some are not. It is therefore important to select the correct properties that have to be updated to ensure that no marginal corrections are introduced. In this paper the standard localization criteria are presented and a technique to separate the global localization criteria in family-based criteria for damped structures is introduced. The methods are analyzed and applied to both numerical and experimental examples; a clear enhancement of the results is noticed using the family-based criteria. A simple way to qualify the stability of a localization method to noise is presented.

Implementation of p and h-p Versions of the Finite Element Method

1992 ◽  
Author(s):  
Ye-Chen Lai ◽  
Timothy C. S. Liang ◽  
Zhenxue Jia
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Analysis ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Shape Functions ◽  
Linear Elastic ◽  
Finite Element Software ◽  
Analysis Process ◽  
Adaptive Analysis

Abstract Based on hierarchic shape functions and an effective convergence procedure, the p-version and h-p adaptive analysis capabilities were incorporated into a finite element software system, called COSMOS/M. The range of the polynomial orders can be varied from 1 to 10 for two dimensional linear elastic analysis. In the h-p adaptive analysis process, a refined mesh are first achieved via adaptive h-refinement. The p-refinement is then added on to the h-version designed mesh by uniformly increasing the degree of the polynomials. Some numerical results computed by COSMOS/M are presented to illustrate the performance of these p and h-p analysis capabilities.

Dynamic Instability of Delaminated Composite Plates under Parametric Excitation

2006 ◽  
Vol 326-328 ◽  
pp. 1765-1768 ◽  
Author(s):  
Meng Kao Yeh ◽  
Kuei Chang Tung
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Parametric Excitation ◽  
Composite Plate ◽  
Dynamic Instability ◽  
Composite Plates ◽  
Modal Parameters ◽  
The Finite Element Method ◽  
Electromagnetic Device ◽  
Instability Regions

The dynamic instability behavior of delaminated composite plates under transverse excitations was investigated experimentally and analytically. An electromagnetic device, acting like a spring with alternating stiffness, was used to parametrically excite the delaminated composite plates transversely. An analytical method, combined with the finite element method, was used to determine the instability regions of the delaminated composite plates based on the modal parameters of the composite plate and the position, the stiffness of the electromagnetic device. The delamination size and position of composite plates were varied to assess their effects on the excitation frequencies of simple and combination resonances in instability regions. The experimental results were found to agree with the analytical ones.

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