An accurate C0 finite element model of moderately thick and deep laminated doubly curved shell considering cross sectional warping

2015 ◽  
Vol 94 ◽  
pp. 384-393 ◽  
Author(s):  
Sandipan Nath Thakur ◽  
Chaitali Ray
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Cross Sectional ◽  
Doubly Curved

Behaviour of cold-formed steel built-up I-section columns composed of four U-profiles

2018 ◽  
Vol 22 (3) ◽  
pp. 613-625 ◽  
Author(s):  
M Anbarasu ◽  
M Venkatesan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Ultimate Strength ◽  
Element Model ◽  
Cross Sectional ◽  
Direct Strength Method ◽  
The North ◽  
Compression Members ◽  
Cross Sectional Dimension ◽  
Cold Formed Steel

This work reports numerical results concerning the cold-formed steel built-up I-section columns composed of four U-profiles under axial compression. A finite element model is developed by using the software program ABAQUS. The developed model includes geometric, material nonlinearities and geometric imperfections. The finite element model was verified against the experimental results reported in the cold-formed steel built-up open section columns. In the parametric study, the sections are analysed with several cross-sectional dimension ratios and lengths, in order to assess their influence on the buckling behaviour and ultimate strength of cold-formed steel built-up I-section columns. After presenting and discussing the numerical parametric results, the article shows that the current direct strength method in the North American Specification for cold-formed steel compression members design curve fails to predict adequately the ultimate strength of some of the columns analysed and addresses the modification proposed on current direct strength method curves, providing improved predictions of all the numerical ultimate strength available. The proposed method is also assessed by reliability analysis.

Finite element model of a novel short stemmed total hip arthroplasty implant developed from cross sectional CT scans

2013 ◽  
Vol 21 (5) ◽  
pp. 493-500 ◽  
Author(s):  
Matthias Lerch ◽  
Nelly Weigel ◽  
Henning Windhagen ◽  
Max Ettinger ◽  
Fritz Thorey ◽  
...  
Keyword(s):  
Finite Element ◽  
Total Hip Arthroplasty ◽  
Finite Element Model ◽  
Hip Arthroplasty ◽  
Element Model ◽  
Ct Scans ◽  
Cross Sectional ◽  
Total Hip

scholarly journals Analysis of the effect of repair welding/grinding on the performance of railway crossings using field measurements and finite element modeling

2017 ◽  
Vol 232 (3) ◽  
pp. 798-815 ◽  
Author(s):  
Lizuo Xin ◽  
Valeri Markine ◽  
Ivan Shevtsov
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Finite Element Model ◽  
Material Properties ◽  
Field Measurements ◽  
Element Model ◽  
Cross Sectional ◽  
Explicit Finite Element ◽  
Repair Welding ◽  
Welding Defect

In this paper, the effects of repair welding and grinding, which are currently the main components used in the maintenance of crossings, on the performance of crossings are analyzed. It has been observed that sometimes the welding and grinding activities that directly affect the geometry of the crossings and/or material properties can have negative effects on the performance and ultimately on the service life of the crossings. In this paper, the effect of the changes of geometry has been studied experimentally, while the effect of the changes in the material properties has been analyzed using a numerical model. When grinding the shape of the crossing nose, the resulting profile can deviate from the original one. To analyze the geometry-related effects of welding and grinding, the geometry of crossings (cross-sectional profiles) as well as the corresponding dynamic accelerations due to passing trains are measured before and after the welding and grinding activities. Based on the comparison of the measured accelerations, the performance of the measured crossings has been assessed. Also, a welding repair that is not properly performed can lead to undesirable changes in the material properties of the rails, resulting in defects in rails. The material-related effects of the welding and grinding are studied using the three-dimensional explicit finite element model wherein a wheelset moves over a railway crossing. To understand the microstructure of the welding defect and provide an input for the numerical model, the results of ultrasonic and microscopic analyses of some welded crossings are presented first. Then, a number of the numerical simulations of the crossing with the welding defect are performed to investigate the failure mechanism of the crossing. Furthermore, assessment using the fatigue model (coupled with the finite element model) that accounts for the ratcheting behavior of material by calculating a number of the load cycles to the crack initiation is performed. Finally, conclusions on the effects of changes in geometry and material of the crossings due to repair welding and grinding are given.

scholarly journals Finite element model of laminate construction element with multi-phase microstructure

2020 ◽  
Vol 27 (1) ◽  
pp. 405-414
Author(s):  
Jerzy Marszałek ◽  
Jacek Stadnicki ◽  
Piotr Danielczyk
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Bending Test ◽  
Cross Sectional ◽  
Limit Values ◽  
Construction Element ◽  
Calculation Results ◽  
Strength And Stiffness ◽  
Sectional Parameters

AbstractThe article describes a method of creating a mesoscale finite element model of a fabric reinforced laminate that replicates the smallest repetitive fragment of its microstructure – RUC (Repetitive Unit Cell). The model takes into account the influence of the number and orientation of layers, the weave of the reinforcement fabric as well as manufacturing technology on the strength and stiffness of the laminate. The constants of the finite elements forming RUC (equivalent cross-sectional parameters, limit values of forces ensuring layer integrity) are determined experimentally by performing uncomplicated tests of specimens of a particular laminate. A special preprocessor was developed to generate the finite element model of the construction element from laminate, which automatically creates the so-called batch file defining the model. The usefulness of the preprocessor was checked by simulating a three-point bending test of a laminate door beam of a passenger car. The obtained calculation results were verified experimentally.

scholarly journals Coupled Bending-Bending-Torsion Vibration of a Rotating Pre-Twisted Beam with Aerofoil Cross-Section and Flexible Root by Finite Element Method

2004 ◽  
Vol 11 (5-6) ◽  
pp. 637-646 ◽  
Author(s):  
Bulent Yardimoglu ◽  
Daniel J. Inman
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Cross Section ◽  
Centrifugal Force ◽  
Axial Stress ◽  
Element Model ◽  
Torsional Stiffness ◽  
Extended Model ◽  
Beam Model ◽  
Cross Sectional

The purpose of this paper is to extend a previously published beam model of a turbine blade including the centrifugal force field and root flexibility effects on a finite element model and to demonstrate the performance, accuracy and efficiency of the extended model for computing the natural frequencies. Therefore, only the modifications due to rotation and elastic root are presented in great detail. Considering the shear center effect on the transverse displacements, the geometric stiffness matrix due to the centrifugal force is developed from the geometric strain energy expression based on the large deflections and the increase of torsional stiffness because of the axial stress. In this work, the root flexibility of the blade is idealized by a continuum model unlike the discrete model approach of a combination of translational and rotational elastic springs, as used by other researchers. The cross-section properties of the fir-tree root of the blade considered as an example are expressed by assigning proper order polynomial functions similar to cross-sectional properties of a tapered blade. The correctness of the present extended finite element model is confirmed by the experimental and calculated results available in the literature. Comparisons of the present model results with those in the literature indicate excellent agreement.

Quick Method for Aeroelastic and Finite Element Modeling of Wind Turbine Blades

2014 ◽  
Author(s):  
Jeffrey Bennett ◽  
Robert Bitsche ◽  
Kim Branner ◽  
Taeseong Kim
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Wind Turbine ◽  
Natural Frequencies ◽  
Turbine Blades ◽  
Element Model ◽  
Wind Turbine Blades ◽  
Quick Method ◽  
Cross Sectional ◽  
Aeroelastic Simulations

In this paper a quick method for modeling composite wind turbine blades is developed for aeroelastic simulations and finite element analyses. The method reduces the time to model a wind turbine blade by automating the creation of a shell finite element model and running it through a cross-sectional analysis tool in order to obtain cross-sectional properties for the aeroelastic simulations. The method utilizes detailed user inputs of the structural layup and aerodynamic profile including ply thickness, orientation, material properties and airfoils to create the models. After the process is complete the user has two models of the same blade, one for performing a structural finite element model analysis and one for aeroelastic simulations. Here, the method is implemented and applied to reverse engineer a structural layup for the NREL 5MW reference blade. The model is verified by comparing natural frequencies to the reference blade. Further, the application to aeroelastic and structural evaluations is demonstrated. Aeroelastic analyses are performed, and predicted fatigue loads are presented. Extreme loads from the aeroelastic simulations are extracted and applied onto the blade for a structural evaluation of the blade strength. Results show that the structural properties and natural frequencies of the developed 5MW blade match well with the reference blade, however the structural analysis found excessive strain at 16% span in the spare caps that would cause the blade to fail.

scholarly journals Vibration Analysis of Rotating Tapered Timoshenko Beams by a New Finite Element Model

2006 ◽  
Vol 13 (2) ◽  
pp. 117-126 ◽  
Author(s):  
Bulent Yardimoglu
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Rectangular Cross Section ◽  
Element Model ◽  
Transverse Displacement ◽  
Timoshenko Beams ◽  
Cross Sectional ◽  
New Model ◽  
Polynomial Coefficients ◽  
Energy Equations

A new finite element model is developed and subsequently used for transverse vibrations of tapered Timoshenko beams with rectangular cross-section. The displacement functions of the finite element are derived from the coupled displacement field (the polynomial coefficients of transverse displacement and cross-sectional rotation are coupled through consideration of the differential equations of equilibrium) approach by considering the tapering functions of breadth and depth of the beam. This procedure reduces the number of nodal variables. The new model can also be used for uniform beams. The stiffness and mass matrices of the finite element model are expressed by using the energy equations. To confirm the accuracy, efficiency, and versatility of the new model, a semi-symbolic computer program in MATLAB® is developed. As illustrative examples, the bending natural frequencies of non-rotating/rotating uniform and tapered Timoshenko beams are obtained and compared with previously published results and the results obtained from the finite element models of solids created in ABAQUS. Excellent agreement is found between the results of new finite element model and the other results.

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