Nonlinear Finite Element Analysis of Pipe Bends Subjected to Inplane Bending

2016 ◽  
Author(s):  
Venkata M. K. Akula ◽  
David W. Martin
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Structural Response ◽  
Sensitivity Analyses ◽  
Model Parameters ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Shell Elements ◽  
Length Changes

Pipe bends are structural components that provide flexibility to accommodate length changes in pipelines while allowing fluid flow. Estimating the collapse load is critical to ensuring the structural integrity of the pipeline. This research discusses modeling and analysis of pipe bends utilizing the finite element method. Three-dimensional models utilizing elbow elements, shell elements, and brick elements are generated to predict the collapse moment of pipe bends subjected to in-plane loading. All simulation was performed using Abaqus. To obtain a more physically-consistent response, material, geometric, and boundary nonlinearities are all included. A MPC user subroutine is utilized to capture the end behavior of the pipe bends correctly when utilizing shell and brick elements. Experimental data from two sources, available in literature, was used to evaluate the effect of the different element types on the predicted structural response. Finally, utilizing the shell, brick, and the elbow elements, parameter sensitivity analyses are performed to identify the key parameters influencing the response of pipe bends. Multiple parameters are varied independently of each other to fully understand and capture their influence on the response. SIMULIA’s Isight software was used to automate the workflow and vary the model parameters about their respective baseline values.

Finite Element Analysis for a CAD of a Concrete Mixer Drum

1994 ◽  
Author(s):  
Hossam S. Badawi ◽  
Sherif A. Mourad ◽  
Sayed M. Metwalli
Keyword(s):  
Finite Element ◽  
Computer Aided Design ◽  
Three Dimensional ◽  
Plain Concrete ◽  
Element Analysis ◽  
Shell Elements ◽  
Bending Stresses ◽  
Loading Effects ◽  
Concrete Mixer ◽  
Aided Design

Abstract For a Computer Aided Design of a concrete truck mixer, a six cubic meter concrete mixer drum is analyzed using the finite element method. The complex mixer drum structure is subjected to pressure loading resulting from the plain concrete inside the drum, in addition to its own weight. The effect of deceleration of the vehicle and the rotational motion of the drum on the reactions and stresses are also considered. Equivalent static loads are used to represent the dynamic loading effects. Three-dimensional shell elements are used to model the drum, and frame elements are used to represent a ring stiffener around the shell. Membrane forces and bending stresses are obtained for different loading conditions. Results are also compared with approximate analysis. The CAD procedure directly used the available drafting and the results were used effectively in the design of the concrete mixer drum.

Finite Element Analysis of Elliptical Chord

2013 ◽  
Vol 3 (4) ◽  
pp. 44-61
Author(s):  
K. S. Narayana ◽  
R. T. Naik ◽  
R. C. Mouli ◽  
L. V. V. Gopala Rao ◽  
R. T. Babu Naik
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Three Dimensional ◽  
Compressive Load ◽  
Dynamic Strength ◽  
Element Analysis ◽  
T Joints ◽  
Shell Elements ◽  
Tubular Joints ◽  
Plane Bending

The work presents the Finite element study of the effect of elliptical chords on the static and dynamic strength of tubular T-joints using ANSYS. Two different geometry configurations of the T-joints have been used, namely Type-1 and Type-2. An elastic analysis has been considered. The Static loading conditions used are: axial load, compressive load, In-plane bending (IPB) and Out-plane bending (OPB). The natural frequencies analysis (dynamic loading condition) has also been carried out. The geometry configurations of the T-joints have been used, vertical tubes are called brace and horizontal tubes are called chords. The joint consists of brace joined perpendicular to the circular chord. In this case the ends of the chord are held fixed. The material used is mild steel. Using ANSYS, finite element modeling and analysis of T-joint has been done under the aforementioned loading cases. It is one of the most powerful methods in use but in many cases it is an expensive analysis especially due to elastic–plastic and creep problems. Usually, three dimensional solid elements or shell elements or the combination of two types of elements are used for generating the tubular joints mesh. In tubular joints, usually the fluid induced vibrations cause the joint to fail under resonance. Therefore the natural frequencies analysis is also an important issue here. Generally the empirical results are required as guide or comparison tool for finite element investigation. It is an effective way to obtain confidence in the results derived. Shell elements have been used to model the assembled geometry. Finite element ANSYS results have been validated with the LUSAS FEA and experimental results, that is within the experimentation error limit of ten percentage.

Oyster Creek Nuclear Generating Station Containment Drywell Buckling Analysis

2010 ◽  
Author(s):  
Soo Bee Kok ◽  
Shu S. Tang ◽  
Francis H. Ku ◽  
Marcos L. Herrera ◽  
John F. O’Rourke ◽  
...  
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Three Dimensional ◽  
Buckling Analysis ◽  
Eigenvalues And Eigenvectors ◽  
Analysis Software ◽  
Element Analysis ◽  
3D Finite Element ◽  
Buckling Stability ◽  
Stability Limits

This article presents the overall methodology and the results of the three-dimensional (3D) finite element buckling analysis of the primary containment drywell shell at the Oyster Creek Nuclear Generating Station (Oyster Creek). The buckling stresses, eigenvalues, and eigenvectors are computed using ANSYS finite element analysis software [1], and the structural integrity of the drywell in terms of the buckling (stability) limits are based on the ASME B&PV Code Case N-284-1 [2].

scholarly journals Vibration and Modal Analysis of Low Earth Orbit Satellite

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Asif Israr
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Integrity ◽  
Center Of Mass ◽  
Low Earth Orbit ◽  
Element Analysis ◽  
Satellite Structure ◽  
Modeling And Analysis ◽  
Material Optimization ◽  
Theoretical Predictions

This paper presents design, modeling, and analysis of satellite model used for remote sensing. A detailed study is carried out for the design and modeling of the satellite structure focusing on the factors such as the selection of material, optimization of shape and geometry, and accommodation of different subsystems and payload. The center of mass is required to be kept within the range of (1-2) cm from its geometric center. Once the model is finalized it is required to be analyzed by the use ofAnsys, a tool for finite element analysis (FEA) under given loading and boundary conditions. Static, modal, and harmonic analyses inAnsysare performed at the time of ground testing and launching phase. The finite element analysis results are also validated and compared with the theoretical predictions. These analyses are quite helpful and suggest that the satellite structure does not fail and retains its structural integrity during launch environment.

The Finite Element Modeling and Analysis of Involute Spur Gear

2012 ◽  
Vol 516-517 ◽  
pp. 673-677 ◽  
Author(s):  
Shun Xu ◽  
Yan Zhang
Keyword(s):  
Finite Element ◽  
Mechanical Design ◽  
Three Dimensional ◽  
Spur Gear ◽  
Analysis Model ◽  
Element Analysis ◽  
Finite Element Analysis Model ◽  
Modeling And Analysis ◽  
Gear Mesh ◽  
Design Software

Through three-dimensional mechanical design software Pro/E to build a spur gear solid model, using ANSYS software for the gear mesh, as well as the constraints imposed by the most unfavorable load to determine the location of the discussion, in order to get accurate finite element analysis model. By analyzing, this shows that the effectiveness of the application of ANSYS in gear calculation.

A Three-Dimensional Finite Element Analysis of Restored Deciduous Canine

2015 ◽  
Vol 638 ◽  
pp. 123-129 ◽  
Author(s):  
Florin Baciu ◽  
Claudia Bratosin ◽  
Aurelia Rusu-Casandra
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Bone Structure ◽  
Three Dimensional ◽  
Medical Problem ◽  
Ct Scanner ◽  
Chronic Infections ◽  
Element Analysis ◽  
Tooth Structure ◽  
Three Dimensional Finite Element

The literature reports that dental cavities are an international public health challenge and treatment of decays especially for young children is a medical problem of great importance. Early childhood caries progress rapidly and can cause functional, physical and dentofacial aesthetic impairment. Recent studies show that caries lesions can compromise children’s quality of life due to the pain and discomfort which could lead to disfigurement, acute and chronic infections and to alteration of meals and sleeping habits. Tooth decay occurs when acids in the mouth dissolve the outer layers of the tooth, stripping the tooth of important minerals. Because dental decay often goes untreated, the cavity grows and more tooth structure is lost. Restorative dentistry has the main purpose of rehabilitating the function and aesthetic of tooth. The structural integrity of the restored teeth depends on the state of stress in their different regions due to occlusal loads. The aim of this study performed with the finite element method is to evaluate the stress and strain distributions in bone structure-primary canine-restorative material assembly when a load of 120N is applied all over the upper surface of the model. Particular attention was given to an accurate computer reconstruction of the canine. Therefore with the aid of a CT scanner the tomography images obtained were processed with a special software (Mimics). Two dental restorative materials, commonly used in practice were chosen for the analysis and the results acquired are compared. Also the contact pressure at the interface bone-deciduous canine and deciduous canine-dental material is evaluated in both cases.

Structural Integrity Assessment Criteria and Service Life Prediction of Cold Wrinklebends

2012 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Finite Element ◽  
Service Life ◽  
Structural Integrity ◽  
Pipeline Steel ◽  
Three Dimensional ◽  
Computation Time ◽  
Element Analysis ◽  
Integrity Assessment ◽  
Fea Model ◽  
Hardening Models

Three-dimensional elastic-plastic finite element analysis (FEA) is performed in this paper to simulate the complicated stresses and deformation of wrinklebends in a pipeline from its bending formation to operation under cyclic loading. Three plastic hardening models (isotropic, kinematic and combined isotropic/kinematic) are discussed and used in FEA of wrinklebend response that considers strain hardening and Bauschinger effects. The FEA simulation is carried out first for an elbow held at constant pressure while subject to cyclic bending, which serves as a benchmark case. The results show that the three hardening models lead to very different outcomes. Comparable FEA simulations are then developed for wrinklebends under cyclic pressure. Detailed parametric analysis is considered, including finite-element type, element sensitivity, computation time, and material input data. Based on those results viable nonlinear FEA model is developed as the basis to quantify wrinklebend response under service-like conditions. Based on the FEA results, fatigue damage is quantified using the Smith, Watson and Topper (SWT) parameter, and thereafter a damage criterion is proposed to predict the fatigue life of a wrinklebend under the pressure cycles of 72%–10% of SMYS for typical X42 pipeline steel. The results show that the wrinkle aspect ratio H/L is a key parameter to control the service life of a wrinklebend.

Virtual Prototype Design and Test-Simplifying the CAD/Analysis Interface

2013 ◽  
Vol 284-287 ◽  
pp. 3473-3476
Author(s):  
Qiong Li ◽  
Carol A. Rubin
Keyword(s):  
Finite Element ◽  
Structural Integrity ◽  
Medial Axis ◽  
Three Dimensional ◽  
Virtual Design ◽  
Element Analysis ◽  
Feature Geometry ◽  
Cad Models ◽  
Structural Parts ◽  
Treat All

The design of mechanical structural parts is now predominantly a digital process. As an important element of the virtual design cycle, these parts must be tested for their structural integrity using finite element analysis (FEA) software. However, the interface between CAD and FEA is imperfect. The process of preparing CAD models for FEA consumes a great deal of the stress analyst’s time. Existing “automatic” CAD to FEA translators tend to treat all part features as “solid”; this leads to longer computation times and less accurate results for features that can be better characterized as “thin” or “long.” In addition, many features of CAD parts (e.g. fillets and chamfers) are important for their size and shape in the manufactured product, but have relatively little impact on the strength of the part and needlessly complicate the stress analysis—these features are usually removed by the analyst prior to FEA; they may need to be evaluated with additional analyses to test if it is safe to remove them. The Automatic CAD-FEA Interface Project (ACFI), is developing algorithms to make the translation from CAD to FEA seamless and automatic; these algorithms are based on mathematical theory and the principles of theoretical mechanics. This paper presents the latest ACFI advances for (i) automatically evaluating and reworking three dimensional CAD part geometries to prepare them for finite element meshing, (ii) exporting the revised geometries to a preprocessor, and (iii) identifying element type to be associated with each feature geometry. The algorithms used in this work approximate the medial axis transform (MAT) of the CAD part, a “power shape” that represents the three-dimensional solid part. This part can then be evaluated for its geometric properties. This approach has been shown to be a robust method for shape interrogation of three dimensional geometries.

A New Tightening Methodology for Gasketed Joints Based on Nonlinear Finite Element Analysis

2008 ◽  
Author(s):  
Sayed A. Nassar ◽  
Zhijun Wu ◽  
Xianjie Yang
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Elastic Interaction ◽  
Element Model ◽  
Nonlinear Finite Element ◽  
Bolted Joints ◽  
Model Parameters ◽  
Element Analysis ◽  
Loading And Unloading ◽  
Nonlinear Finite Element Model

A three dimensional nonlinear finite element model is developed for achieving a uniform clamp load in gasketed bolted joints. The model is used for both multiple and single pass tightening patterns. Geometric nonlinearity of the gasket is taken into account and plastic model parameters are experimentally determined. The effect of the tightening pattern, gasket loading and unloading history, and the preload level is investigated. The validity of the FEA methodology is experimentally verified. This study helps improve the reliability of gasketed bolted joints by minimizing the bolt-to-bolt clamp load variation caused by elastic interaction among the various bolts in the joint during initial joint bolt-up.

Intelligent Automatic Mesh Generation for Multichip Modules

1993 ◽  
Author(s):  
Anagha G. Jog ◽  
Ian R. Grosse ◽  
Daniel D. Corkill
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Mesh Generation ◽  
A Priori ◽  
Three Dimensional ◽  
Element Model ◽  
Design Tool ◽  
Element Analysis ◽  
Modeling And Analysis ◽  
Element Modeling

Abstract Currently, the pre-processing stage of finite element analysis is a major stumbling block towards automation of the entire finite element modeling and analysis (FEMA) process. The lack of complete automation of FEMA greatly limits its impact as a design tool. This paper presents a blackboard-based, object-oriented modeling system for intelligent a-priori automatic three dimensional mesh generation. The modeling system enables the user to define the physical system at a natural domain-specific high level of abstraction and automatically derives lower-level finite element model representations. Knowledge sources interact with the blackboard to make modeling idealizations and select optimal meshing strategies. An example application in the domain of finite element modeling of multi-chip module microelectronic devices is presented.

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