Finite Element-Based Parametric Investigations of the Stepped-Lap Repairs to Laminated Cylindrical Shell

2011 ◽  
Vol 90-93 ◽  
pp. 2682-2690
Author(s):  
Jian Xin Xu ◽  
Lu Chun Zhao ◽  
Ding He Li
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Cylindrical Shells ◽  
Fe Model ◽  
Stacking Sequence ◽  
Improve Design ◽  
Analysis Techniques ◽  
Insight Into ◽  
Laminated Cylindrical Shell ◽  
Load Conditions

A parametric finite element (FE) model was developed to allow a broad investigation into the influence of various parameters, such as load conditions, stacking sequence and the number of steps on the performance of the stepped-lap repairs in composite laminated cylindrical shells. And the peak stresses determined with respect to changes in stacking sequence and the number of steps. Furthermore, the adhesive stress distribution resulting from joining mismatched laminate cylindrical shells was investigated. The results of this investigation provide further insight into the stresses that develop in stepped repairs of composite structures under load. This insight may lead to improve design and analysis techniques of stepped repairs in composite structures.

Structure-Soil Interaction of Buried Corrugated Steel Arch Bridge

2010 ◽  
Vol 163-167 ◽  
pp. 2112-2117
Author(s):  
Miao Xin Zhang ◽  
Bao Dong Liu ◽  
Peng Fei Li ◽  
Zhi Mao Feng
Keyword(s):  
Finite Element ◽  
Steel Structures ◽  
Internal Force ◽  
Structural Deformation ◽  
Fe Model ◽  
Soil Pressure ◽  
Load Range ◽  
Finite Element Program ◽  
Load Conditions ◽  
Peak Value

Corrugated steel plate and surrounding soils are working together to share the load in buried corrugated steel structures. It is complicated to consider the structure-soil interaction, so the finite element method has already become the chief means of complicated structure analysis. Based on a practical project, considering structure-soil interaction, by using the finite element program of ANSYS, the paper set up a 2-D FE model and analyzed the soil pressure, the structural deformation and the internal force under different load conditions in detail. The analysis shows that structure-soil interaction has brought about stresses redistribution of surrounding soils, and adverse effects of soil pressure and displacement were limited. The variation range of soil pressure on the crown of arch increases with the load increases and the peak value of soil pressure approach to the code value and a rebound appears in the vehicle load range. The tendencies of vertical soil displacement are nearly the same to different load conditions, and the peak value of moments has an obvious change and can be influenced greatly by deflective load.

Finite Element Modeling and Experimental Characterization of Enhanced Hybrid Composite Structures for Improved Crashworthiness

2013 ◽  
Vol 80 (5) ◽  
Author(s):  
Luciana Arronche ◽  
Israel Martínez ◽  
Valeria La Saponara ◽  
Elias Ledesma
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Hybrid Composite ◽  
Composite Structures ◽  
Testing Machine ◽  
Strain Curve ◽  
Qualitative Behavior ◽  
Fe Model ◽  
Impact Tests ◽  
Highly Nonlinear

In this work, two hybrid composite structures were designed, modeled, and tested for improved resistance to impact. They were inspired by bistable composite structures, which are structures composed of two parts: a so-called “main link” and a so-called “waiting link.” These links work together as a mechanism that will provide enhanced damage tolerance, and the structure exhibits a bistable stress/strain curve under static tension. The function of the main link is to break early, at which point the waiting link becomes active and provides a redundant load path. The goal of the current study was to design, manufacture, and test a similar concept for impact loading and achieve greatly improved impact resistance per unit weight. In the current project, the main link was designed to be a brittle composite material (in this case, woven carbon/epoxy) exposed to impact, while the waiting link was chosen to be made with a highly nonlinear and strong composite material (in this case, polyethylene/epoxy), on the opposite surface. Hence, the structure, if proven successful, can be considered an enhanced hybrid concept. An explicit finite element (FE) commercial code, LS-DYNA, was used to design and analyze the baseline as well as two proposed designs. The simulations' methodology was validated with results published in the literature, which reported tests from linear fiber-reinforced composites. The plots were obtained via the ASCII files generated from the FE code, processed using matlab®, and compared to experimental impact tests. An instrumented drop-weight testing machine performed impact tests, and a high-speed camera validated the specimens' displacement under impact. It is shown that the FE model provided qualitative behavior very consistent with the experiments but requires further improvements. Experimentally, it is shown that one of the two enhanced hybrid models leads to up to a 30% increase of returned energy/weight when compared to its baseline and, therefore, is worthy of further investigations.

FE Modeling of EB-FRP Strengthened RC Beams

2014 ◽  
Vol 1065-1069 ◽  
pp. 1147-1150
Author(s):  
Kang Liu
Keyword(s):  
Finite Element ◽  
Fe Model ◽  
Rc Beams ◽  
Fe Modeling ◽  
Test Results ◽  
Structural System ◽  
Externally Bonded ◽  
Insight Into

A finite element (FE) model for externally bonded FRP (EB-FRP) strengthened RC beams is developed to simulate the responses of the structural system, to gain a better insight into the mechanism of the system. Comparisons between the predictions of the model and test results are presented to demonstrate its capability and accuracy.

Analysis of Composite Bolted Connection Joints Under Out of Plane Loading

2020 ◽  
Author(s):  
Hassan A. Mahmoud ◽  
Mostafa Shazly ◽  
Yehia Bahei-El-Din ◽  
Emad El-Kashif
Keyword(s):  
Finite Element ◽  
Areal Density ◽  
Finite Element Models ◽  
Fe Model ◽  
Stacking Sequence ◽  
Bolted Connection ◽  
Structural Applications ◽  
Edge Distance ◽  
Out Of Plane ◽  
Bolt Diameter

Abstract The use of composite joints has been increased in recent years in structural applications such as aircraft, civil engineering structure, ship structure, wind energy sector, and automotive industry. In this paper, the behaviour of composite bolted connection joints under out of plane loading is investigated. A parametric study was conducted to study the joint stiffness variation with various geometric parameters, which include the edge distance, bolt diameter, plate width, and the laminate stacking sequence. The experimental work was conducted on GFRP tension clips (L-angle) joint specimens manufactured by the vacuum infusion technique. In the present work, two types of laminates were used, unidirectional laminates [0°]5 with an areal density of 1050 gm/m2, triaxial laminates [−45°/+45°/0°]5 with an areal density of 1200 g/m2. A 3D finite element (FE) model was developed to study the effect of joint parameters on its stiffness. Finite element models were constructed, and the experimental results were used to validate the finite element models. The analysis concluded that the failure load increases when the edge distance to bolt diameter ratio (E/D) increases and the triaxial stacking sequence is better than unidirectional. The (E/D) ratio, the (W/D) ratio and stacking sequence were found to be very significant parameters.

To Understand Myopic Alleviation by Conducting Finite Element Structural Analysis of a Cornea With an Intrastromal Corneal Ring Implant

2015 ◽  
Author(s):  
Salman N. Khan ◽  
Panos S. Shiakolas
Keyword(s):  
Finite Element ◽  
Focal Length ◽  
Optical Power ◽  
The United States ◽  
Valuable Insight ◽  
Fe Model ◽  
Computationally Efficient ◽  
Intrastromal Corneal Ring ◽  
Light Rays ◽  
Insight Into

Myopia or shortsightedness is a visual impairment condition that is affecting more than 32 million Americans according to the American Academy of Ophthalmology, and this number is expected to increase even further with the increasing life expectancy in the United States. Myopia occurs when light rays entering the cornea are focused in front of the retina due to: high corneal curvature, short axial length of the eye, or high optical power of the natural lens. These reasons suggest that light refracting elements play a pivotal role in determining visual acuity. The cornea is the principal refractive element in the eye contributing almost 75 percent of ocular refractive power and if the shape of the cornea can be changed to increase or decrease the focal length of the converging light rays it could present a possible solution to improving myopia. The presented research focuses on the effects of intrastromal corneal ring (ICR) implantation on the shape of the cornea by developing a computationally efficient 3D axisymmetric finite element (FE) model of the cornea utilizing hyperelastic material properties. The results of the developed corneal FE model with a 360° ICR implant are analyzed and discussed. The FE model results provide confidence in the ability of the ICR implants to reduce myopia. The attained FE model results not only agree qualitatively with published clinical data but also provide a valuable insight into the surgery.

scholarly journals Non-linear Vibrations of Deep Cylindrical Shells by thep-Version Finite Element Method

2010 ◽  
Vol 17 (1) ◽  
pp. 21-37 ◽  
Author(s):  
Pedro Ribeiro ◽  
Bruno Cochelin ◽  
Sergio Bellizzi
Keyword(s):  
Finite Element ◽  
Degrees Of Freedom ◽  
Natural Frequencies ◽  
Numerical Study ◽  
Cylindrical Shells ◽  
Element Formulation ◽  
Fe Model ◽  
Various Boundary Conditions ◽  
Non Linear ◽  
Linear Vibrations

Ap-version shell finite element based on the so-called shallow shell theory is for the first time employed to study vibrations of deep cylindrical shells. The finite element formulation for deep shells is presented and the linear natural frequencies of different shells, with various boundary conditions, are computed. These linear natural frequencies are compared with published results and with results obtained using a commercial software finite element package; good agreement is found. External forces are applied and the displacements in the geometrically non-linear regime computed with thep-model are found to be close to the ones computed using a commercial FE package. In all numerical tests thep-FE model requires far fewer degrees of freedom than the regular FE models. A numerical study on the dynamic behaviour of deep shells is finally carried out.

Representation of bolted joints in a structure using finite element modelling and model updating

2020 ◽  
Vol 14 (3) ◽  
pp. 7141-7151 ◽  
Author(s):  
R. Omar ◽  
M. N. Abdul Rani ◽  
M. A. Yunus
Keyword(s):  
Finite Element ◽  
Dynamic Behaviour ◽  
Model Updating ◽  
Complex Structure ◽  
Bolted Joints ◽  
Model Parameters ◽  
Fe Model ◽  
Bolted Joint ◽  
Fe Modelling ◽  
Joint Structure

Efficient and accurate finite element (FE) modelling of bolted joints is essential for increasing confidence in the investigation of structural vibrations. However, modelling of bolted joints for the investigation is often found to be very challenging. This paper proposes an appropriate FE representation of bolted joints for the prediction of the dynamic behaviour of a bolted joint structure. Two different FE models of the bolted joint structure with two different FE element connectors, which are CBEAM and CBUSH, representing the bolted joints are developed. Modal updating is used to correlate the two FE models with the experimental model. The dynamic behaviour of the two FE models is compared with experimental modal analysis to evaluate and determine the most appropriate FE model of the bolted joint structure. The comparison reveals that the CBUSH element connectors based FE model has a greater capability in representing the bolted joints with 86 percent accuracy and greater efficiency in updating the model parameters. The proposed modelling technique will be useful in the modelling of a complex structure with a large number of bolted joints.

Torsional Analysis of a Steel Cord-Rubber Tire Belt Structure

1996 ◽  
Vol 24 (4) ◽  
pp. 339-348 ◽  
Author(s):  
R. M. V. Pidaparti
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Composite Structures ◽  
Three Dimensional ◽  
Element Model ◽  
Torsional Stiffness ◽  
Element Analysis ◽  
Rubber Belt ◽  
Steel Cord ◽  
Torsional Analysis

Abstract A three-dimensional (3D) beam finite element model was developed to investigate the torsional stiffness of a twisted steel-reinforced cord-rubber belt structure. The present 3D beam element takes into account the coupled extension, bending, and twisting deformations characteristic of the complex behavior of cord-rubber composite structures. The extension-twisting coupling due to the twisted nature of the cords was also considered in the finite element model. The results of torsional stiffness obtained from the finite element analysis for twisted cords and the two-ply steel cord-rubber belt structure are compared to the experimental data and other alternate solutions available in the literature. The effects of cord orientation, anisotropy, and rubber core surrounding the twisted cords on the torsional stiffness properties are presented and discussed.

Finite Element Analysis of Composite Cylindrical Shells with and without Cutouts

2012 ◽  
Vol 1 (1) ◽  
pp. 34-38
Author(s):  
B. Siva Konda Reddy ◽  
◽  
CH. Srikanth ◽  
G. Sandeep Kumar ◽  
◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cylindrical Shells ◽  
Element Analysis ◽  
Composite Cylindrical Shells

Behaviour of Axially Loaded Composite Wall Panel by Using Finite Element Analysis

2015 ◽  
Vol 815 ◽  
pp. 49-53
Author(s):  
Nur Fitriah Isa ◽  
Mohd Zulham Affandi Mohd Zahid ◽  
Liyana Ahmad Sofri ◽  
Norrazman Zaiha Zainol ◽  
Muhammad Azizi Azizan ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Element Analysis ◽  
Steel Sheets ◽  
Linear Behavior ◽  
Non Linear ◽  
Composite Wall ◽  
Experimental Values ◽  
Civil Engineering Infrastructure

In order to promote the efficient use of composite materials in civil engineering infrastructure, effort is being directed at the development of design criteria for composite structures. Insofar as design with regard to behavior is concerned, it is well known that a key step is to investigate the influence of geometric differences on the non-linear behavior of the panels. One possible approach is to use the validated numerical model based on the non-linear finite element analysis (FEA). The validation of the composite panel’s element using Trim-deck and Span-deck steel sheets under axial load shows that the present results have very good agreement with experimental references. The developed finite element (FE) models are found to reasonably simulate load-displacement response, stress condition, giving percentage of differences below than 15% compared to the experimental values. Trim-deck design provides better axial resistance than Span-deck. More concrete in between due to larger area of contact is the factor that contributes to its resistance.

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