Multi-Field FE Modeling of Resistive Heating in a 6061-T6511 Aluminum Specimen

2006 ◽  
Author(s):  
Amir Khalilollahi ◽  
David H. Johnson ◽  
John Roth
Keyword(s):  
Finite Element ◽  
Mechanical Energy ◽  
Element Model ◽  
Tensile Specimen ◽  
Effect Of Temperature ◽  
Transient Temperature ◽  
Fe Model ◽  
Stress Strain ◽  
Aluminum Specimen ◽  
Property Changes

Electric current's effect on material mechanical properties has been of interest since it can lessen the mechanical energy associated with deforming/working a material. The objective of this work is to have a representative model of the thermal/structural effects of electricity on a tensile specimen so that the simple effect of temperature can be separated from any mechanical material property changes due to the electric current. The finite element models in this study were generated and their results were compared to experimental data obtained from a representative tensile test. Comparison with the experimental results on material engineering stress-strain curves and transient temperature profiles offers assurance for the further use of FEA as a significant tool in understanding the electrical effects on material properties. A multi-field large deformation finite element model for a cylindrical tensile bar of 6061-T6511 aluminum is developed to evaluate the distribution of temperature within the specimen. The model also evaluates the stress-strain characteristics of the material while the specimen is carrying a large DC current and being deformed. The simulation results are compared to surface infrared temperature measurements in order to verify the FE model first and then to attain more qualitative and possibly quantitative insight into the effects of electric field.

A Comparative Multifield FEA and Experimental Study on the Enhanced Manufacturability of 6061-T6511 Aluminum Using dc Current

2009 ◽  
Vol 131 (6) ◽  
Author(s):  
Amir Khalilollahi ◽  
David H. Johnson ◽  
John T. Roth
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Tensile Specimen ◽  
Transient Temperature ◽  
Stress Strain ◽  
Strain Behavior ◽  
Deformation Force ◽  
Property Changes ◽  
Dc Current

An electric current, applied during deformation, has been shown to reduce the deformation force/energy, while also increasing the maximum achievable strain and decreasing springback. Considering this, the present work initiates the development of a finite element model to investigate electricity’s thermal/structural effects on a tensile specimen. The model allows the effect of joule-heating to be separated from other nonthermal property changes caused by the electricity. Comparison with experimental tensile testing with respect to the predicted stress-strain behavior and transient temperature profiles demonstrates the model predicts these behaviors adequately. A multifield large deformation finite element model is then developed. The model evaluates the stress-strain characteristics of the material while the specimen is carrying a large dc current and is being deformed, incorporating the effect of thermal softening. The simulation results are compared with surface infrared temperature measurements in order to verify the finite element model and then to actual deformation results in order to attain more qualitative and quantitative insight into the effects of the electric field.

A Finite-Element Model for Residual Stresses and Deflections in Girth-Butt Welded Pipes

1978 ◽  
Vol 100 (3) ◽  
pp. 256-262 ◽  
Author(s):  
E. F. Rybicki ◽  
D. W. Schmueser ◽  
R. W. Stonesifer ◽  
J. J. Groom ◽  
H. W. Mishler
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Computational Models ◽  
Strain Range ◽  
Element Model ◽  
304 Stainless Steel ◽  
Transient Temperature ◽  
Stress Strain ◽  
Nonlinear Stress ◽  
Welded Pipe

Computational models for predicting transient temperature distributions, residual stresses, and residual deflections for girth-butt welds are described. Comparisons of predicted and measured temperatures for a two-pass welded pipe show agreement to within 9 percent and 17 percent of the measured values for passes one and two, respectively, the model for predicting residual stresses and residual deflections is based on a finite-element representation recognizing individual passes, temperature dependent elastic-plastic constitutive behavior, elastic unloading for material in the nonlinear stress-strain range, and changes in geometry due to the deformation of each weld pass. Load incrementation and incremental stress-strain relations are also used. Results for a two-pass girth-butt welded pipe show good correlation between residual stresses and residual deflections obtained from the computational model and data obtained from a welded 304 stainless steel pipe.

КОНСТРУКТИВНО-ТЕХНОЛОГІЧНІ ОСОБЛИВОСТІ ХВОСТО-ВИХ БАЛОК СІТЧАСТОГО ТИПУ З ПОЛІМЕРНИХ КОМПО-ЗИЦІЙНИХ МАТЕРІАЛІВ ВЕРТОЛЬОТІВ ТРАНСПОРТНОЇ КАТЕГОРІЇ

2020 ◽  
pp. 15-30
Author(s):  
А. Г. Гребеников ◽  
И. В. Малков ◽  
В. А. Урбанович ◽  
Н. И. Москаленко ◽  
Д. С. Колодийчик
Keyword(s):  
Finite Element ◽  
Strain State ◽  
Layer Structure ◽  
Metal Structure ◽  
Element Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Mesh Structure ◽  
Stress Strain State ◽  
Mesh Structures

The analysis of the design and technological features of the tail boom (ТB) of a helicopter made of polymer composite materials (PCM) is carried out.Three structural and technological concepts are distinguished - semi-monocoque (reinforced metal structure), monocoque (three-layer structure) and mesh-type structure. The high weight and economic efficiency of mesh structures is shown, which allows them to be used in aerospace engineering. The physicomechanical characteristics of the network structures are estimated and their uniqueness is shown. The use of mesh structures can reduce the weight of the product by a factor of two or more.The stress-strain state (SSS) of the proposed tail boom design is determined. The analysis of methods for calculating the characteristics of the total SSS of conical mesh shells is carried out. The design of the tail boom is presented, the design diagram of the tail boom of the transport category rotorcraft is developed. A finite element model was created using the Siemens NX 7.5 system. The calculation of the stress-strain state (SSS) of the HC of the helicopter was carried out on the basis of the developed structural scheme using the Advanced Simulation module of the Siemens NX 7.5 system. The main zones of probable fatigue failure of tail booms are determined. Finite Element Analysis (FEA) provides a theoretical basis for design decisions.Shown is the effect of the type of technological process selected for the production of the tail boom on the strength of the HB structure. The stability of the characteristics of the PCM tail boom largely depends on the extent to which its design is suitable for the use of mechanized and automated production processes.A method for the manufacture of a helicopter tail boom from PCM by the automated winding method is proposed. A variant of computer modeling of the tail boom of a mesh structure made of PCM is shown.The automated winding technology can be recommended for implementation in the design of the composite tail boom of the Mi-2 and Mi-8 helicopters.

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

Finite Element Mesh Generator Applying Constraints’ Propagation and Isoparametric Mapping

1991 ◽  
Author(s):  
J. Rodriguez ◽  
M. Him
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Finite Element Mesh ◽  
Fe Model ◽  
Element Analysis ◽  
Element Mesh ◽  
Mesh Generator ◽  
Generation Algorithm ◽  
Essential Input

Abstract This paper presents a finite element mesh generation algorithm (PREPAT) designed to automatically discretize two-dimensional domains. The mesh generation algorithm is a mapping scheme which creates a uniform isoparametric FE model based on a pre-partitioned domain of the component. The proposed algorithm provides a faster and more accurate tool in the pre-processing phase of a Finite Element Analysis (FEA). A primary goal of the developed mesh generator is to create a finite element model requiring only essential input from the analyst. As a result, the generator code utilizes only a sketch, based on geometric primitives, and information relating to loading/boundary conditions. These conditions represents the constraints that are propagated throughout the model and the available finite elements are uniformly mapped in the resulting sub-domains. Relative advantages and limitations of the mesh generator are discussed. Examples are presented to illustrate the accuracy, efficiency and applicability of PREPAT.

scholarly journals On the issue of dynamic loading of supporting structures of special wheeled chassis

2019 ◽  
pp. 73-83
Author(s):  
V. I. Tarichko ◽  
P. I. Shalupina
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Loading ◽  
Strain State ◽  
Element Model ◽  
Stress Strain ◽  
Full Size ◽  
Equivalent Stresses ◽  
Stress Strain State ◽  
Supporting Structures

The paper focuses on a method for assessing the dynamic loading of the frame of a special wheeled chassis when it moves on roads of various categories. Based on the developed finite element model of the frame, we obtained and analyzed full-size patterns of the stress-strain state of the frame and oscillograms of equivalent stresses in the most loaded zones of the frame.

scholarly journals Finite element analysis to assess the biomechanical behavior of a finger model gripping handles with different diameters

2019 ◽  
Vol 11 (1) ◽  
pp. 69-79 ◽  
Author(s):  
Benedict Jain A.R. Tony ◽  
Masilamany S. Alphin
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Subcutaneous Tissue ◽  
Fe Model ◽  
Stress Strain ◽  
Element Analysis ◽  
Biomechanical Behavior ◽  
Biomechanical Response ◽  
Human Finger ◽  
Finger Model

SummaryStudy aim: Interactions between the fingers and a handle can be analyzed using a finite element finger model. Hence, the biomechanical response of a hybrid human finger model during contact with varying diameter cylindrical handles was investigated numerically in the present study using ABAQUS/CAE.Materials and methods: The finite element index finger model consists of three segments: the proximal, middle, and distal phalanges. The finger model comprises skin, bone, subcutaneous tissue and nail. The skin and subcutaneous tissues were assumed to be non-linearly elastic and linearly visco-elastic. The FE model was applied to predict the contact interaction between the fingers and a handle with 10 N, 20 N, 40 N and 50 N grip forces for four different diameter handles (30 mm, 40 mm, 44mm and 50 mm). The model predictions projected the biomechanical response of the finger during the static gripping analysis with 200 incremental steps.Results: The simulation results showed that the increase in contact area reduced the maximal compressive stress/strain and also the contact pressure on finger skin. It was hypothesized in this study that the diameter of the handle influences the stress/strain and contact pressure within the soft tissue during the contact interactions.Conclusions: The present study may be useful to study the behavior of the finger model under the static gripping of hand-held power tools.

Sign in / Sign up

Export Citation Format

Share Document