Simulating Real Life: Software With No Boundaries
Simulating Real Life: Software With No Boundaries
| ABSTRACTS
Here is some of the papers to be presented at the 1998 ANSYS Conference. TABLE OF CONTENTS:
Natural Convection in a Vertical Concrete Cask (VCC) Designed for Storage of Spent Nuclear FuelYuanyue Jin,Engineering & Design Services NAC International Norcross, Georgia, USA Michael C. Yaksh
ABSTRACT The vertical concrete cask (VCC) is a design for dry storage
of high-level nuclear waste, spent nuclear fuel. The VCC mainly consists
of canister, which contains the spent fuel, a right circular cylinder concrete
overpack, and the air annulus between the canister and the concrete overpack.
Heat generated by the spent fuel is rejected to the surface of the canister
by radiation and conduction. The air annulus provides a path of air circulation,
which allows for the rejection of heat by natural convection. The concrete
overpack provides neutron and gamma radiation shielding, and it is subjected
to thermal boundary conditions of solar insolance, natural convection,
and thermal radiation to the ambient. A 2-D axisymmetric finite element
CFD model, including thermal radiation across the air annulus region, is
developed using ANSYS FLOTRAN. Solution of the fluid flow and the temperature
distribution is achieved using FLOTRAN. The temperature dependence of the
material properties is considered during the solution process. The results
indicate, that the heat generated by the spent fuel is mainly carried out
by the natural circulation of air through the VCC. The radiation heat transfer
across the air annulus is found to be significant. In conjunction with
the development of a parametric model to accomplish the design of a family
of VCCs, a benchmark was performed demonstrating the adequacy of the methodology.
UNSTEADY FLOW, AND AEROELASTICITY ANALYSED BY A NEW SOFTWAREAnders B. Eriksson and Jari HyvarinenAnker-Zemer Engineering AB Karlskoga, Sweden ABSTRACT The efficiency, and in many cases surprisingly high accuracy,
of the Potential fluid flow method is often under estimated by engineers.
Solvers based on potential flow often produce satisfactory solutions in
short time for problems that would present overwhelmingly complex tasks
for a full Navier-Stokes solver. A program that uses the potential flow
equations is our new program called LINFLOW. LINFLOW is a user-friendly
and computatively fast solver for 3D steady and unsteady fluid flow analyses.
In LINFLOW spatial discretization is based on the boundary element method
(BEM). This makes meshing simple since only the structural surfaces need
to be meshed, not the surrounding fluid domain. Lifting structures (e.g.
aeroplane wings) can be modelled by attaching planar wake elements to the
model. We have developed an interface between ANSYS and LINFLOW to utilize
ANSYS pre- and post-processors, and the structural analysis tools present
in ANSYS. The user may use LINFLOW together with the modal analysis tools
in ANSYS to efficiently anslyse the stability of structures that interact
with fluid flow (a broad range of aeroelastic stability phonomena may be
analysed). For example, the critical regions of a flight envelope can be
studied and flutter boundaries predicted. In this presentation we compare
LINFLOW results with experimental results from NASA for an elastically
supported NACA0012 finite wing. The steady flow field and the critical
flutter speed are determined by LINFLOW with good agreement to experiments.
Another aspect of LINFLOW's capabilities is also presented by analysing
the natural frequencies of a steel ring submerged in water.
FE ANALYSIS OF MANDREL FIBER-OPTIC HYDROPHONES SENSITIVITIES USING ANSYSJong-in Im and Youg-rae RohABSTRACT This paper investigates the influence of structural parameters
on the performance of an optical fiber wound mandrel hydrophone using ANSYS.
Studied parameters are mandrel geometry, thickness of the molding coated
over the fiber, and material properties of constitutional parts of the
hydrophone. Analysis result shows that sensitivity of the hydrophone increases
with the length of the mandrel and the thickness of the molding. Higher
sensitivity also requires a mandrel or molding material of relatively low
Young's modulus and Poisson's ratio. On the other hand, flat frequency
response range of the hydrophone increases as either the mandrel length
becomes shorter or the mandrel materials becomes harder. The omni-directional
characteristic is improved also with the shorter mandrel. Hence, some trade-off
of the geometrical and the material parameters must be made to accomplish
the best performance of the hydrophone.
TOWARD MODELLING THE FORMATION OF MINERAL DEPOSITS: TWO AND THREE-DIMENSIONAL CALCULATIONS OF TRANSPORT PROCESSES ASSOCIATED WITH CONVECTION IN FREEZING MAGMA CHAMBERS AND ATTENDANT HYDROTHERMAL CIRCULATION IN COUNTRY ROCKKeith P. HarrisonDepartment of Physics Rhodes University Grahamstown, South Africa Alan R. Rice
Andre Botha
John M. Moore
Sotari Panagou
Shaun D. Bangay
Peter G. Clayton
ABSTRACT A program to model theoretically the formation of mineral
deposits of interest (e.g. copper, gold, platinum, etc) has been initiated
to assist exploration efforts, ore reserve estimation and to guide mine
production. This theoretical effort relies mainly on the FLOTRAN finite
element code which is a part of the ANSYS software package. Provided herein
are some initial results which arose in constructing the infrastructure
for undertaking this effort. Although 2-D calculations will be presented
for comparison, we have performed the first 3-D calculations of magma chamber
cooling and the response of the enclosing country rock. These results are
also the first to include collectively the effects of variable viscosity
and suspended crystal load. We have also attempted to mimic solidification
at the walls through the effect of variable viscosity (FLOTRAN as yet does
not support phase change). These are also the first results to obtain reasonable
Rayleigh numbers for mafic magma chambers (e.g. 1014 ) and hence
are the first results in the truly turbulent flow regime for such chambers.
Further, these are the first results to couple the hydrothermal circulation
to the cooling history of the magma chamber and vice versa. The effect
of geothermal gradient is also included. FLOTRAN provides wide flexibility
in this effort with regard to spacial variation in the permeability of
the country rock. There are few limitations, also, in the configuration
or shape of the geology to be modelled. The use of FLOTRAN has allowed
us to dismiss many of the simplifying assumptions commonly found in the
literature that attend the descriptive equations employed for assessing
magma chamber dynamics (e.g. the complete set of streaming terms are retained
in the momentum equations rather than dropped, as has been the universal
approach in order to cut down on calculation expense and time). In addition,
we have separately developed interactive fly-through capabilities for the
graphical display of results in order to rotate or slice up the modelled
ore body to examine in detail its time evolution. A general observation
is that non-symmetric, complex structure is common (e.g. in temperature
distributions) although completely symmetric boundary and initial conditions
have been applied. Time evolution of these complexities will be shown.
The initial results of this program have provided useful insight into processes
of emplacement of ore bodies and have allowed us to propose explanations
for observations in the field that have been enigmatic. A video of transient
results will be shown.
COMPOSITE SIMULATIONSLead Technical Chair: Grama BhashyamSession Chairs: Peter Kohnke, Pakal Rahulkumar Reviewed by: Grama Bhashyam, Ray Browell, Dave Conover, Peter Kohnke, and Seker Govindarajan ABSTRACT The failure process of a motor case in aramid/epoxi is
analyzed. The residual stresses created in the cure process of the matrix
epoxy are introduced in the model. This process is modelled numerically
and compared with the measurements taken after the fabrication of the motor
case. The nonlinear behaviour is considered in the model. The damage of
the matrix demonstrated to be a very important factor in the failure mechanism.
DEVELOPING A FRP-SANDWICH STRUCTURE OF A 72 M WEIGHT OPTIMIZED STEALTH CORVETTESten M. R. Vallbo and Johan E. EdvardssonSystems/Hull Kokums AB Karlskronavarvet Kariskrona, Sweden ABSTRACT This paper presents the use of FEA in the development
of the structure of the FRP-sandwich (Fibre Reinforced Plastics) fully
stealth optimized Visby class corvette. The driving requirements for the
structure have been; extremely light weight and an integration of stealth
qualities into the structure. The FRP-sandwich concept with carbon fibre
laminates was found to fulfill the requirements. The complexity of the
chosen concept have however called for an extensive use of FEA in order
to ensure structural strength and stiffness of the hull. Experience gained
from 25 years of building GRP-sandwich (Glass fibre Reinforced Plastics)
mine-sweepers have formed the platform for the further developing program
together with the results from the prototype stealth vessel called Smyge.
During the years, the use of FEA have gradually become a more important
design tool. Today, typical analysis includes a complete hull structure
model for global loads and submodels for detailed analysis of slamming
loads and foundations. Modeling techniques, evaluation of the results and
special considerations concerning sandwich structures and FEA are discussed.
MICROMECHANICAL AND MACROMECHANICAL FAILURE ANALYSIS OF GRAPHITE-EPOXY COMPOSITESAnil Saigal and Robert GreifDepartment of Mechanical Engineering Tufts University Medford, MA 02155 ABSTRACT This paper is an investigation of the failure of unidirectional
[90] and 8-ply [0/0/90/90]s P75 Graphite/934 Epoxy composites subjected
to mechanical and thermal loads. Thermal residual stresses develop as a
result of the differences in the coefficients of thermal expansion of the
fiber and the matrix, and the difference in temperature between the operating
and stress-free (or cure) temperatures. Both micro and macro-mechanical
models are used to analyze failure mechanisms. The micro-mechanical model
uses finite element methods (FEM) based on the ANSYS program for a fiber/matrix
configuration that simulates the actual composite structure. The initiation
and propagation of failure at the fiber/matrix interface is carefully examined.
The procedure is iterative, in order to properly account for the failed
nodes and to maintain equilibrium. The effects of different boundary condition
assumptions are analyzed in order to ensure accurate simulations. The macro-mechanical
model uses laminated plate theory (LPT) based on average material properties.
Failure criteria include maximum stress and Tsai-Wu criteria. Since LPT
is often used to design composite structures, it is essential to compare
FEM and LTP. FEM provides more details on the exact distribution of failure
at the fiber/matrix interface, and the propagation of failure with increasing
loads. In general, FEM predicts initial failure at a lower stress than
LPT, and in this sense, FEM is more conservative than LPT in analyzing
composite structures.
CONTACT SIMULATIONSLead Technical Chair: Grama BhashyamSession Chairs: Dave Conover, Yongyi Zhu Reviewed by: John Dulis, Sekar Govindarajan, Yong-Cheng Liu, and Yongui Zhu ABSTRACT The ANSYS finite element code was used to predict the
elastic deformation of a fiber optic ferrule assembly. First, the symmetric
contact between two ferrule assemblies was analyzed to determine the contact
load distribution and the fiber recession range which results in fiber
contact. Three models of increasing material composition complexity were
analyzed to baseline the performance and to explore the effects of fiber
recession. Finite element predictions of contact deformation were validated
by comparison with a known analytical solution. Numerical predictions for
allowable fiber recession ranges and load partitioning are in excellent
agreement with numerical analyses conducted by other investigators using
the finite element and boundary element methods. Predicted fiber recession
ranges are also in accord with accepted manufacturing standards. Next,
the analysis was extended to model a complete optical experiment to correlate
experimental measurements of contact zone size with numerical predictions.
Again, numerical predictions of contact zone size are in excellent agreement
with experimental measurements.
STUDIES OF CONTACT PROBLEMS AND CYCLIC PLASTICITY IN HIGH-PRESSURE TOOLS BY USE OF NON-LINEAR FE ANALYSESTorben Birker and Thomas Orts PedersenSTRECON® Technology Danfoss A/S DK-6400 Sonderborg, Denmark ABSTRACT A short introduction to the products of STRECON® Technology is given and the principle and technology on which the products are based is described. The feature of ANSYS to simulate initial interference is used to model the shrink fitting of the strip-wound container and die. For this purpose, contact elements are used. As the analyses include elastic-plastiic material behavior, a weak initial stiffness is applied to the contact elements. The stiffness is gradually increased over several load steps. Thus, it is possible to simulate yielding of the tool materials during the shrink fitting [1]. A tool for cold forging of bevel gears used in automobiles is used as illustrative example. Dies used in strip-wound containers are typically loaded
cyclically with surface pressures alternating between 0 and 2-6 GPa. Despite
the use of high strength tool steels or tungsten carbides, the materials
may be subjected to plastic yielding. Hence, a risk of fatigue crack initiation
is present. To analyze this problem and to establish means for proper designs
of dies and strip-wound containers, a material model suitable for describing
complex cycle loadings should be applied. In this work, a material model
based on mixed non-linear hardening [2] is implemented in ANSYS using the
user-programmable feature userpl (UPF). The model is used to study the
influence of applied pre-stressing concept on permanent changes in the
geometry during a number of load cycles for a die for manufacture of industrial
synthetic diamonds.
APPLICATION OF THE FINITE ELEMENT METHOD IN COLD FORGING PROCESSESCristina Maria Oliveira Lima RoqueSergio Tonini Button School of Mechanical Engineering, State University of Campinas, Campinas, SP, 13083-970, Caixa Postal 6122, Brazil (email: crism@fem.unicamp.br) ABSTRACT The demand for more efficient manufacturing processes
has been increasing in the last few years. The cold forging process is
presented as a possible solution, because it allows the production of parts
with a good surface finishing and with good mechanical properties. Nevertheless,
the cold forming sequence design is very empirical and it is based on the
designer experience. The computational modeling of each forming process
stage by the finite element method can make the sequence design faster
and more efficient, decreasing the use of conventional "trial and error"
methods. In this study the application of a commercial general finite element
software - ANSYS - has been applied to model a forming operation. Models
have been developed to simulate the ring compression test and to simulate
a basic forming operation (upsetting) that is applied in most of the cold
forging parts sequences. The simulated upsetting operation is one stage
of the automotive starter parts manufacturing process. Experiments have
been done to obtain the stress-strain material curve, the material flow
during the simulated stage and the required forming force. These experiments
provided results used as numerical model input data and as validation of
model results. The comparison between experiments and numerical results
confirms the developed methodology potential in the forming processes simulation.
ANALYSIS OF FRICTION AND INTERFACIAL SLIP IN CROSS WEDGE ROLLING USING EXPLICIT DYNAMIC FEMM.R. Lovell, K.A. Tagavi, and Y. DongDepartment of Mechanical Engineering & Center for Manufacturing Systems University of Kentucky ABSTRACT Friction and interfacial slip in metal forming processes
are very important parameters when considering tool design, tool wear,
and finished product integrity. This paper investigates the interfacial
slip between the forming tool and workpiece in a relatively new metal forming
process, cross wedge rolling (CWR). After a brief description of CWR is
given, a three-dimensional finite element model is introduced which realistically
characterizes the interfacial slip that occurs during a flat-wedge CWR
process. Finite element results, which are generated for various workpiece
area reductions, are verified using experimental data obtained from a CWR
prototype machine that was specially designed and constructed for understanding
the deformations encountered in CWR. From the close agreement between the
experiment and numerical results, it is shown that all of the important
physical phenomena in the nonlinear deformation process of CWR are included
in the FEM. The relevance of developing such a model, as applied to automating
CWR tool design, is subsequently discussed.
A GENERAL TOOL FOR FINITE ELEMENT SIMULATION OF LONG-TIME SLIDING WEARPar-Ola Andersson, Martin Eriksson, and Ake BurmanDepartment of machine Design, Lund Institute of Technologyat Lund University, Lund Sweden ABSTRACT Finite Element (FE) modeling and simulation of long-time wear is an interesting topic with many fields of application, i.e. gear transmission analyses and biomechanics. The difficulties lie in the process of continuously updating and modelling the altered contact surface and contact pressure that result from unsymmetric wear over a long period of time. To do this, the geometry has to be changed due to the wear throughout the simulation. In this work, a wear module is implemented into the FE solftware ANSYS, using User Programmable Features (UPF). The module is general, and can be used to perform long-time wear simulations of bodies in sliding contact. The model is automatically updated, and no redefinition of data is needed. The wear theory used in the implementation is outlined,
as well as the wear calculation procedure. To show on the capabilities
of the module and to verify the implementation, two examples of long-time
wear simulations are reported in the study. The implementation can be used
by an engineering designer in lifetime studies, investigation of structural
behavior due to mechanical wear etc.
CUSTOMIZATION AND EDUCATIONLead Technical Chair: Dale OstergaardSession Chairs: Greg Sharpe and Eric Clevenger Reviewed by: Ray Browell, Dave Conover, Dave Looman, Jay Oppenheim, Dale Ostergaard, Ahmed Salem, and John Swanson ABSTRACT A customized version of the ANSYS® program has been developed for AlliedSignal Engines which improves productivity for the over 200 engineers and analysts who use it in their daily work. The enhancements made to the AlliedSignal version of ANSYS fall into three main categories: The paper will illustrate the improved productivity which
results from using these added features, examples of the programming involved
to create them, and the results from our experiences using them.
DEVELOPMENT OF EXCEL-BASED EASY-INPUT SYSTEM FOR ANSYSYasumasa Shoji and Satoshi NagataEngineering Technology Department Toyo Engineering Corporation Narashino, Chiba, Japan ABSTRACT In this paper we will report our development of easy-to-use input systems for ANSYS and show the effectiveness of the systems. In chemical plants, there are several types of pressure vessels which require fatigue evaluation in their design. If they are required to comply with an appropriate Design Codes, we must analyze those pressure vessels to obtain stress condition considering the stress concentration. As the stress concentration normally occurs at such structural discontinuity portions as a nozzle neck, a flange hub and so on, the portions are selected from the vessels regarding to the severity for fatigue design. On the other hand, as stress concentration analysis needs fine meshes with precise geometry definition, it takes a long time and much cost. If we do these kinds of jobs in one-by-one basis, it is sometimes too long comparing to the total engineering time even the works are "routine" for us, and the cost is too much relative to the total engineering fee. To overcome this situation, we developed easy-to-use input systems and design optimization tools for the detailed analyses on the portions of vessels. The newly developed systems are based on widely used Microsoft EXCEL on an ordinary Windows-95 personal computer to deliver freely to any designer in our company. The Excel-based input systems have reduced our engineering time and costs remarkably. The optimization tools are aiming to reduce the number of design-analysis loops before reaching a "good" design. The tools employed the "design optimization" function of ANSYS and are kinds of templates. These newly developed systems reduced our engineering time and cost, especially analysis time, roughly from one month to one week. Our system development was realized because of ANSYS's
unique functions, such as its built-in pre-processor and the data compatibility
between engineering work stations and personal computers.
CUSTOMIZED SYSTEM FOR STRUCTURAL ANALYSIS OF CRANE BOOMSFatima Maria Nogueira de SouzaSoftware Technology Ltda Rio de Janeiro, Brazil Leonardo Vilain Joao
Alexandre Hansen
ABSTRACT This paper describes an ANSYS customized system, developed by SOFTEC, to evaluate the crane boom structural capability of operating with damaged members. The ANSYS UIDL (User interface Design Language) is used to define specific windows. The calculations are performed by ANSYS solver and macros. The service was requested by PETROBRAS, to be used in sectors where services depend on the cranes. The goal of the system is to analyze the damaged crane boom performance and guarantee that the boom can be operated with reliability with a specific load. The system permits to exclude, recuperate or modify boom lacings and model damages such as local strain, corrosion, local and global eccentricity in crane boom members. Macros were developed to: The system makes the user's job faster and more efficient
and consequently improve the productivity. Operating costs and losses are
minimized and the production increases.
SYNTHESIZING ENTERPRISE-WIDE ENGINEERING INTO EDUCATIONKathleen L. KittoEngineering Technology Western Washington University Bellingham, Washington, USA ABSTRACT Even though enterprise-wide engineering is widely considered a methodology to improve the bottom line in industrial applications, the synthesis of an enterprise-wide engineering philosophy into educational environments is equally important. Students who are entering the market place after graduation find themselves immersed in a world where product time to market and rapid development to manufacturing are keys to corporate success. To be properly prepared for this environment, students should be immersed in the same enterprise-wide philosophy while they are undergraduates. For the past six years, faculty in the Engineering Technology Department at Western Washington University have incorporated concurrent engineering and enterprise-wide engineering into their courses and into various undergraduate research/design projects. For the past eight years, ANSYS has been used to teach introductory finite element analysis (FEA) and computer aided engineering (CAE) tools. ANSYS also has been widely used for FEA in undergraduate senior capstone projects, undergraduate research projects, and in student design competition programs. This paper describes the integration of enterprise-wide
engineering within the six Engineering Technology Department programs:
Manufacturing Engineering Technology, Plastics Engineering Technology,
Electronics Engineering Technology, Industrial Design, Industrial Technology
and Technology Education. The paper further describes recent senior capstone
projects where ANSYS and solid modeling programs such as Pro/E or Solid
Edge have been used. Undergraduate research projects that have made significant
use of CAD/CAM and FEA are also described. Specific CAM programs used include:
Pro/Manufacture, SmartCAM, MasterCAM and EasyCAM. Finally, the paper outlines
goals for creating a total enterprise-wide system within the department
during the next five years that includes a major infrastructure network
upgrade and the addition of three new CAE laboratories that will be jointly
funded by Western Washington University and Boeing.
Incremental Magnetic Inductance ComputationMiklos Gyimesi and Dale OstergaardANSYS, Inc. Canonsburg, PA, U.S.A. The paper introduces the enhanced incremental energy method,
EIEM, for the accurate and efficient computation of nonlinear differential
inductance coefficients.
Electromagnetic Particle Trajectory TracingMiklos Gyimesi, Vladmir Zhulin, Dale OstergaardANSYS, Inc. Canonsburg, PA, U.S.A. The paper describes the electromagnetic particle trajectory
tracing capability of the ANSYS commercial finite element program.
3D Induction Heating Simulation of a Helical GearBill BulatSilverado Software and Consulting Huntington Beach, CA Mahyar S. Dadkhah
Scott A. Schroeder
ABSTRACT A simulation of the induction heating of a helical gear using a 3D finite element model was performed. A collection of input files and software "macros" were created in which the gear and coil geometry and the coil excitation were parameterized to simplify re-specification in design studies in a productive environment. The files automated a solution procedure which accounted for the coupling which exists between electromagnetic and thermal phenomena during induction heating. This solution procedure consisted of sequential executions of harmonic response electromagnetic and transient thermal analyses in iterative loop. Joule heating calculated by the harmonic electromagnetic analysis was used as an input load in a single time step of the transient thermal analysis. New temperatures predicted at the end of the time step were used in the subsequent harmonic electromagnetic analysis for material property evaluation. This procedure allowed the strong variations in magnetic permeability and electrical and thermal conductivities which exist over the range of temperatures produced by induction heating to be taken into account. One phenomenon having a potentially significant effect
on the outcome of induction heating is magnetic saturation. Due to a lack
of material property data, saturation effects were not incorporated in
the present study. Despite error anticipated by the omission of this effect,
work proceeded to establish the feasibility of and groundwork for performing
this kind of coupled field simulation with a 3D finite element model. When
the data becomes available, it will be incorporated into this ongoing effort
using a procedure which will be described subsequently. Results were compared
to experimental measurements to verify the simulation method in preparation
for applying it in a production environment.
No Year 2000 BoundariesSamuel A. Murgie, Manager Systems EngineeringANSYS, Inc. Canonsburg, PA ABSTRACT The Twenty-first Century will provide challenges for us all. The first of these challenges is the issue of the century date change itself. This is due to the fact that many applications, operating systems, databases, and processes will have logic problems when the two-character data representations for the year changes from 99 to 00 and beyond. ANSYS, Inc. is committed to having its products, services, and business operations functioning during the century date change and beyond. We have taken steps to ensure that our flagship ANSYS product line is Year 2000 compliant with the 5.4 release. Additionally, we are currently in the midst of ensuring that our other products, services, and business operations will function so well during the century date change that it would appear to the outside world that we were unaffected by the date change. ANSYS, Inc. has a two-prong assault on the Year 2000 dilemma.
First, is to ensure that all products are Year 2000 compliant, and to ensure
that they remain so. The second is a comprehensive Year 2000 Project Plan
to address our ability to do business at the start of the next century.
Both assaults are well on their way; far enough, in fact, that we are confident
that we will be able to provide products, services, and support that first
week of January, 2000.
Maximizing the Efficiency and Benefits of a Quality System for Software Engineering Through the Use of CASE and CAST ToolsKenneth G. PodlaszewskiQuality Assurance Engineer ANSYS, Inc. Canonsburg, PA ABSTRACT Quality systems which encompass all aspects of software
development and delivery have long been considered instrumental in providing
quality software. Advances in desktop computing and available CASE and
CAST tools has made it possible to go from a minimal, expensive and sometimes
agonizing infrastructure required by the software engineering quality system
to a much more advanced, useful and symbiotic system that facilitates as
well as supports the quality system. This paper will investigate the use
of CASE and CAST tools to support and facilitate software engineering quality
systems. Practical cases from the quality system in use at ANSYS, Inc.
will be used to demonstrate how such tools can improve the quality of software,
increase cost effectiveness in developing, delivering and servicing software
and how tools can serve as a catalyst for continuous improvement of a quality
system.
Nonlinear Transient and Steady State Thermal-electric Coupled Field Analysis of a Conductor for CryogenicsPavel HanzelkaAcademy of Sciences of the Czech RepublicInstitute of Scientific Instruments Brno, CZ Tibor Bachorec
ABSTRACT This paper shows how a nonlinear transient and steady
state thermal-electric coupled field analysis of a conductor applied in
cryogenics can be performed to understand the lead behavior using the ANSYS
5.4 new Multiphysics capabilities. The thermal problem involves conduction,
as well as, radiation. The resistively, thermal conductivity and specific
heat are strongly dependent on temperature. The analysis determines the
temperature and electric potential distribution along the conductor, radiated
and conducted part of the generated heat. Experience with numerical stability
of the voltage and current driven FE models are also included. A comparison
of the finite element result with the measured temperature is made, too.
A Shell Optimization Add-On Module for ANSYS Rev. 5.4Frank VogelFuerth, Germany G.Mueller
ABSTRACT The purpose of this paper is to describe the development
and the application of a new optimization strategy POPT, developed by the
authors and incorporated into ANSYS Rev. 5.4 to efficiently solve shell
thickness optimization problems of large scale. We will first review the
fundamentals of the techniques and algorithms involved of both, the mathematical
optimization algorithm and the analytical gradient calculation for displacement
(i.e. nodal displacement, ...) and eignevalue dependent (i.e. natural frequency,
...) functions with respect to shell thicknesses. After that we describe
the set of additional ANSYS commands developed to set up an POPT shell
optimization problem, and the steps necessary to take account of any user-defined
displacement dependent function into the optimization problem. Then, some
applications and conclusions are presented.
Finite Element Analysis of Distortion and Residual Stress of Welded PlatesM. Meo and R. VignjevicCollege of Aeronautics Cranfield University Bedford, United Kingdom ABSTRACT This paper presents the results of a study aimed at establishing
distortion and residual stress due to the welding process in welded aluminum
plates. The material considered was of A1-2024-T3, commonly used for aircraft
components. Moreover, the effect of thickness and width of plate over residual
stress distribution and distortion were investigated. A numerical analysis
of welding process was carried out with ANSYS Finite Element Code.
Validation of the ANSYS CONTAC12 Element Used for Predicting Gaps Under Seismic LoadsH.S. Sehmi and R.J. GibsonRolls Royce and Associates Limited Derby, England ABSTRACT This paper describes work carried out to test the performance of the CONTAC12 gap element under seismic loads. The purpose of this work was to provide validation of the element when used for predicting the behaviour of structures likely to lift under such loads. The validation is based on comparison of experimental results from a series of shaker table tests with results from ANSYS. The main variables considered in the study were the gap stiffness and the magnitude of the seismic motion. In the analytical model, a number of damping models were also considered. The main conclusion of the study is that the CONTAC12 element in ANSYS performs correctly under seismic loads, but within the limitations on modeling damping. Currently, the direct time integration method used in ANSYS for solving non-linear transients problems does not support modal damping. A best estimate solution can be obtained by identifying the governing damping mechanism and using the x-B damping model appropriately. For this study, the stiffness (B) based damping model provided the best estimate solution. However, the results obtained were found to be generally optimistic. To overcome this, a conservative solution can be obtained by using zero damping. During the course of this study, a technique for including
modal damping in a direct time integration analysis in ANSYS was uncovered.
The logistics of this technique are briefly outlined in this paper, although
it is recognized that its proper implementation into ANSYS would require
further work.
Sheet Forming Process Simulation and Implicit Spring-Back RelaxationU.KocabiqakDeparmtne of Mechanical Engineering
M.Firat
T.Kurtay
ABSTRACT Increased potential for solving large-scale finite element models with even desktop Computers coupled with market pressure for faster sheet metal die-design result about the extensive use of explicit FEA codes like ANSYS/LS-DYNA in automotive industry. The aim of this paper is to evaluate the mathematical models used in die surface modeling and to determine the effects on both the deep-drawing analysis and spring-back quality. The two alternatives, that is traditional finite elements vs. Pure geometrical surfaces like IGES Standards, exist for modeling rigid tool in multi-stage forming. The need for several trimming operations results into a number dio set-ups to be used in the process simulations. From a global perspective, the errors introduced due to improper surface curvatures at each die set-up and due to incorrect spring-back analysis will propagate for next stages which makes the analyses useless. The paper will point-out the variation of stretching ratio
and spring-back form and amount wrt. The tool surface representation. In
addition, an methodology to evaluate the relaxation of residual stresses
over the workpiece during explicit spring-back analysis will be presented.
For verification purposes, all first order results are compared with experimental
ones over one automotive sheet design.
Dimensioning of Composite Structures with a New Failure Criterion in ANSYSClemens Kaiser, Reiner GleichmarChair for Lighweight-Structures, Technische Universitat Munchen Munich, Germany Martin Kracht, Klemens Rother
ABSTRACT In co-operation with CAD-FEM GmbH Grafing and Burgdorf, Germany, the chair of Lightweight-Structures at the Technische Universitat Munchen implemented the new inter-fiber-failure hypothesis of Puck into the commercial FE-program ANSYS. This new physically based failure criterion of Puck, meanwhile confirmed experimentally, allows a more detailed analysis of the failure-type of composite laminates than all the failure criteria used in ANSYS up to now. In ANSYS the criterion of maximum stress and maximum strain and the Tsai/Wu criterion are available. The implementation of the action plane related inter-fiber-failure (IFF) criterion of Puck into ANSYS was made by an external program, which can be called up by simple commands from the post-processor. For that only two additional fracture-values have to be defined in the data table during the pre-processing. With that, it is now possible to make a more differentiating
analysis regarding to the failure behaviour during the design process of
a composite structure. Distinguishing between fiber-failure (FF) and IFF
and specification of the IFF mode allows an optimization of geometry and
material for an optimal carrying capacity of the structure. An example
shows the simple usage of the external program, the correct calculation
of experimental results, and the extensive power of expression of the new
failure hypothesis.
Finite Element Analysis of Catheter Navigation through Tortuous Body VesselsBrendan Cunniffe B. E., Dr. Peter McHugh, Dr. Conchur O'Bradaigh, and R. Bard Galway, IrelandABSTRACT The paper will discuss the development of an explicit
finite element model to simulate the behavior of the distal portion of
a medical catheter in a tortuous body vessel. The objective was to replace
some of the expensive experimental trials currently used to develop catheters
with modeling analyses. Studies were performed to gauge the effects of
different parameters in the model. Considerable effort had to be made to
control mesh instabilities and contact penetrations in the different analyses.
Validation of the finite element models was carried out through comparisons
between FE results and results obtained from laboratory tests.
Life Assessment of Chest Valve Under Pressure and Thermal StressesProf. R. Miroshnik, A. Jeager, and Dr. H. B. HaimR&D Division Israel Electrical Corp. Haifa, Israel ABSTRACT The goal of the paper is to estimate the service life's model of the power station chest valve. The chest valve is located at the outlet of the main steam piping forward to the turbine. After 23 years of service several circular fatigue cracks have been discovered at the bottom of the chest valve chamber. Finite element analyses of transient thermal stresses, caused by power station startup, are carried out in the work. The finite element Solid-5 with transitional degrees of freedom per node is used to generate actual element mesh. This thermal-structure solid element enables us to model the stress-strain state by considering the steel thermal conductivity and thermal convection process between steel and steam due to static and transient thermal loads. Since there are planes of symmetry in chest valve, only one eighth of the chest valve is modeled with appropriately applied symmetry boundary conditions. The analyses results give a good correlation between the theoretical locations of the maximum stresses and actual locations of the cracks. There is a good agreement between theoretical evaluation and actual life assessment, as well. The possibility of machining out cracks in order to prevent
their growing is examined here. The machining enables us to extend the
power station component's service life.
Biomechanics of Acetablular Press-Fit in Total Hip Replacement:Evaluation of Modeling Parameters for an Idealized 3-D ModelLarisa GoldmintsDepartment of Civil and Environmental EngineeringCarnegie Mellon University, Pittsburgh, Pennsylvania Branislav Jaramaz
Anthony M. DiGioia III
ABSTRACT The subject of this study is biomechanical modeling of joint replacement in Total Hip Replacement surgery. In particular, it deals with the acetabular side of the joint, during and immediately following the insertion of the cementless acetabular implant. Selection of the appropriate oversize of the acetabular component relative to the acetabular cavity decreases the risk of intraoperative fracture and short-term postoperative implant loosening. In order to determine the appropriate oversize of the acetabular cup and to understand the effects of stress shielding responsible for the long-term implant loosening, it is necessary to analyze stress and strain fields in the bone produced by the insertion of the prosthesis. A 3-D finite element model of the acetabulum of an idealized geometry, created using ANSYS 5.3 finite element software, is used to analyze the press-fitting of an oversized hemispherical acetabular cup during surgery and immediate postoperative activity. An attempt is made to account for the complexity of material properties and plastic behavior as well as the accurate modeling of frictional contact of bone-implant interface during the press-fitting. Special emphasis is given to the accuracy of the finite element model and the results of the finite element analysis. For the finite element model, an additional study is performed to choose the appropriate mesh resolution and to make a decision on the small vs. Large deformations assumption. To avoid numerical instability and ensure the accuracy of results, a sensitivity analysis is performed with respect to "contact stiffness", a numerical parameter regulating the contact between two surfaces. The idealized 3-D model used in this study does not fully account for the complexity in the geometry nor for all aspects of the bone material behavior, and therefore represents an intermediate step between the simple 2-D models and anatomically accurate 3-D models. Yet, it gives more information and better insight into the biomechanical process in the acetabulum during and right after the Total Hip Replacement surgery than 2-D or axisymmetric models. Results obtained during the analysis are in accordance
with the reports of experimental studies. In particular, zones with the
maximum stresses occur in the same regions of the acetabulum where the
fractures during the experimental tests were reported.
Accuracy of the Finite Element Method for an Internal Fixation Fixation Forearm Fracture PlateIsaac Flitta and Xavier VelayDepartment of Product Design and Manufacture School of Design, Engineering and Computing Bournemouth University Bournemouth, United Kingdom ABSTRACT The purpose of this paper is to discuss the differences found in results when using an irregular and regular mesh, and the advantages of the regular mesh. The study was con ducted on the design of internal fixation forearm fracture devices. During services, internal fixation devices are normally subjected to cyclic stresses, which occasionally result in their failure. Ten different designs of the fracture plate were developed in order to optimize the implant geometry, the stress/strain ratio and the deflection. They were modeled on the I-DEAS Master Series software for structural analysis using the finite element method. In order to produce an accurate an reliable analysis an efficient modeling process was performed. To improve the accuracy of the new designs, a regular mesh was applied to the models using solid brick elements. With the same boundary conditions and analysis set ups, the results were correlating with the experiments and no more discrepancies were found. The management and the display of the results were easier and faster. The use of ANSYS improved the understanding of the fracture
plate behavior under complex loading and conducted to an optimum design.
The accuracy and mathematical advantage of the regular mesh helped to save
time and reduced cost while building confidence on the optimum design.
The new design will be manufactured and physically tested before being
implanted in patients in the near future.
Numerical Evaluation of Fatigue Behavior Using FalancsKlemens RotherCAD-FEM GmbH Grafing/Munich, Germany ABSTRACT The sizing of parts with respect to static loading using numerical simulation is state of the art and a widely acknowledged tool to proof feasibility. In case of cyclic loading this holds true only for a few industrial applications. High risk of products with respect to cyclic loading is existent for a lot of applications. Pressure vessel technology, nuclear energy, traffic industry, structural engineering and mechanical engineering are areas in which cyclic loaded parts are produced. Spectacular and tragic failures like for example the collapse of the oil platform "Alexander Kielland" in 1980 where 123 people died, underline the high cooperate and especially economic risk induced by cyclic loaded parts. The fear of developers to be on the unsafe side of the evaluation of cyclic stresses sometimes leads to the situation that new development issues are not tried out. This is dangerous because to survive in competition is endangered without innovation. This paper shows that useable tools are available to do
fatigue evaluations economically and in early stages of development. A
design department using these methods constantly over a longer period of
time will gain experience in addition to experimental fatigue evaluations.
In combination with a verifying test cost for prototypes can be reduced
dramatically
using a numerically optimized part.
Thermal and Dynamic Evaluation and Optimization of Paper Mill ScannersMetin OzenASTECH Manufacturing, Inc. Santa Ana, California, U.S.A. Kenneth Joyce
ABSTRACT Paper mill scanners consist of structural and electronic
components that require a careful integration through analysis and optimization.
The structure has to sustain the harsh vibration environment of paper mills
as well as satisfying the cooling requirements of the electronic components.
ANSYS has been used as an analysis and optimization tool where the diversity
of analyses options made it possible to evaluate the various designs. Design
evaluation criteria necessitated analyses in the following principles;
static, modal, single point response spectrum, steady-state and transient
heat transfer, and coupled Computational Fluid Dynamics (CFD). This paper
describes the different aspects of the scanner design and how the design
and analysis/optimization cycle was achieved through the use of a diversified
finite element code like ANSYS.
Using Design-of-Experiments Techniques for an Efficient Finite Element Study of the Influence of Changed Parameters in DesignMartin ErikssonPär-Ola Andersson and Åke BurmanDeparment of Machine Design Lund Institute of Technology at Lund University, Lund Sweden ABSTRACT All designs are marred by uncertainties and tolerances in dimensions, load levels., etc. Traditionally, one has often over-dimensioned to take these uncertainties into account. The demand for optimized designs with high quality and reliability increases, which means that more sophisticated methods have been developed, see e.g. Lochner and Matar (1990). By describing the fluctuations in design parameters in terms of distributions with expectation and variance, the design can be examined with statistical methods, which results in a more optimized design. This treatment of the design often demands several experiments, and to plan these experiments Design Of Experiments (DOE) techniques, see e.g. Montgomery (1991), are often used. By using DOE methods the design variables are systematically altered, which minimizes the number of experiments needed. The output of the experiments is the results of a specified response function, giving an indication of the influence of design variable fluctuations. A FME system is a suitable tool when performing repeated, similar analyses. Examples exist where the DOE process has been performed externally and then transferred to the FEM system in the form of parameter sets defining the analysis cases that are to be solved, see e.g. Summers et al. (1996) and Billings (1996). This paper describes a statistical DOE module based on
Taguchi's method that works within ANSYS. The module plans the FEM analysis
and calculates the standard statistical moments of the FEM result. This
module serves as a powerful tool for the engineering designer or analysts
when examining the influence of variance and mean value of different design
variables. It also serves as an exploration of where to concentrate an
optimization process.
Optimization of the Parameters Introduced by a Modularized Modeling Approach Based on the Sub-structuring MethodDrogou RaphaelDepartment of Machine Design Royal Institute of Technology, KTH Stockholm, Sweden ABSTRACT Modularization is many times an efficient method to reduce
the complexity of a generic product that frequently is adapted and produced
in small series. A product module is usually a subsystem with a well defined
function and well defined interfaces, that can be connected to other subsystems.
Numerical modeling of both the geometry and the physical behavior of modularized
products would also benefit from a modularized approach, where a submodel
can be retrieved from a database and properly connected to other submodels.
Attributes, such as material properties, FE model, and a definition of
the geometry of the interfaces and the related degrees of freedom (DOF),
is preferably contained within each submodel. This paper presents a modularized
approach to the modeling of the dynamic behavior of products and an optimization
tool that has been implemented as an ANSYS macro.
Designing an Impeller Hub Using Topology OptimizationAndreas Back-PedersenGrundfos A/S Bjerringbro, Denmark ABSTRACT The method of topology optimization is introduced. The theory of the method is presented and discretized, and an algorithm for preventing checkerboard pattern in the final topology layout is outlined. The topology optimization method is implemented as a User Programmable Feature within the ANSYS software environment using an external optimizer. The implemented topology optimization design tool has
been used for initial design study of an impeller hub. Topology optimizations
have been performed for both single and multiple load cases. Based on the
initial design study, basic geometry's for manufacturing and shape optimization
have been elaborated.
ANSYS Analyses of Gas and Oil EquipmentEvgueni L. MouravinChief Expert JSC "Central Design Office for Oil and Gas Equipment" Podolsk, Russia Victor V. Alksnin
ABSTRACT Feasibility of gas and oil equipment (pressure vessels) serviceable capability is made by applicance of normative documents (standards, codes) on the basis of theoretically and experimentally reasonable decisions of the applied mechanics, strength criteria and safety factors. The normative documents solve the probelm of vessel strength as a whole, but, nevertheless, in many cases leave many questions opened. Practical engineering problems arise with designing vessels, if the design parameters are outside the normative parameters, if the transients take place in and etc. After a vessel manufactured and put into operation it is necessary to analyze defective zones, consequence of operation in undersign modes and in case of a fire, etc. In these cases the FEM modeling enables to get answers and adequate results. There are some examples of these applications realized in CKBN (Central Design Office for Oil and Gas Equipment, Russia, Moscow region, Podolsk). Results given below are obtained with the system of the ANSYS-analysis. Example of simulating real life emergency situation, i.e.
column performance in fire conditions is considered in details. Solution
of such problems affords to answer a number of important questions dealing
with evaluation of vessel condition in a fire and to determine fire-extinguishing
parameters.
A Coupled Fluid-Structural Procedure for the Analysis of Journal Bearings with Structural DeflectionsRobert W. StephensonR.W. Stephenson & Associates Cincinnati, Ohio Keith E. Rouch
ABSTRACT In many journal bearing applications, the radial structural
deflections of both the bearing journal and the bearing housing can have
a significant effect on the performance of the bearing. Experience has
shown that these deflections should be accounted for in an analysis to
properly evaluate the bearing design since the structural deflections and
the pressure solution in the oil film are coupled. In this paper, a method
is shown in which substructure matrices from ANSYS finite element models
of the journal and bearing housing are used in the bearing analysis. The
hybrid hydrodynamic-hydrostatic bearing solution is solved using a separate
computer program, and the structural deflections are accounted for by importing
the ANSYS substructure information in terms of a flexibility matrix. The
bearing program then iterates as necessary to converge on the pressure
and deflection solution.
Optimization of the SKILSAW Gear HousingAlex Yatskov, Ph.D, P.E.Compression, Inc. Indianapolis, Indiana ABSTRACT Optimization of the SKILSAW Gear Box Housing is described. The goal of optimization was in the part material reduction without the stress increasing in the critical areas. Ways of seeking effective variants of structure design are shown. A comparative analysis of variants with different Gear box Housing design and parametric optimization of structure in a space of eight geometric variable parameters are conducted. The mass of the Housing and Von Mises in the critical areas are selected as the optimization criterion. The search of the optimal design is realized through mathematical modeling on computer using PROE modeling, ANSYS FEA package, and sensitivity theory. Realization of this optimization approach permitted, with
a relatively small number of calculation points (N=19), to reduce the material
content by 21% of and reduce the stress in the critical areas. If some
of the constraints are relaxed, the material content may be reduced even
more. It allowed SKILSAW manufacturer to substantially cut the cost of
the product and gain a better understanding of the design improvement.
Maintenance and Product Cost Reduced by Implementation of Numerical Simulations and New Material Technology into the Production Process at Norsk Hydro A/SJari HyvärinenAnker-Zemer Engineering AB Karlskoga, Sweden ABSTRACT This paper describes the analysis work performed to improve
the 44 big fans (4.2 m in diameter) included in the pollution control system
at a Norsk Hydro aluminum plant. The performed analysis work include such
areas of engineering as computational fluid dynamics, structural analysis,
and composite materials. The development of the new system was initiated
by an analysis to check if ANSYS/FLOTRAN could determine the physical reasons
for the high maintenance cost of the original system. The initial work
was followed by a series of analysis improving the aerodynamics and reducing
the weight of the fan. Maintenance and pollution control costs were reduced
significantly. The weight of the complete fan system for the final design
was 69% less than for the original design. This result was achieved by
using analysis tools to find the "optimum" concept of the design.
Support Structure of the Chinese Large Astronomical Reflecting Schmidt TelescopeDehua Yang & Xiangqun CuiNanjing Astronomical Instruments Research CenterChinese Academy of Sciences Nanjing, Jiangsu, P.R. China ABSTRACT In about seven coming years, China will build a distinctive
astronomical telescope, the Large Sky Area Multi-object
Fiber Spectroscopic Telescope (LAMOST), which is a very especially
designed reflecting Schmidt telescope. It will have both the large field
of view (5 degree) and the large aperture (4 meters). The reflecting Schmidt
plate MA will not only serve as the correcting plate for eliminating
the spherical aberration of the primary mirror MB, but also
will serve as the tracking mirror simultaneously during the observation
with an alt-azimuth mounting. The support structure of MA, corresponding
to its 24 hexagonal sub-mirrors, is composed of 24 hexagonal sub-mirror
cells and a primary MA cell which is a space truss support structure.
This paper presents the optimization design and analysis of MA
cell, the support structure. Aided by ANSYS, a currently optimal configuration
of the structure with approximate dimension of 6x5x3 meters was reached.
According to static and modal analyses, the structure is comparatively
light, about 3516 kg, while very stiff, the lowest natural frequency is
22.68 Hz. During 1.5 hours continuous observation, the image quality degrading
due to gravity deflection needs no active correction. All the results are
acceptable.
Attachment of Mating Faces - An Interrelational Feature ApproachMany engineering systems are characterized by a physical behavior that to a large extent is determined by complex interactions between subsystems. FE modeling and simulation of the physical behavior of complex systems is enabled by methods and technologies that allow subsystems to be modeled independently of other subsystems, and where systems models can be aggregated from a set of submodels, that may be defined at various levels of abstraction, i.e. detailed, coarse, and condensed super-elements. A method to attach pairs of nodally incompatible submodels is presented in this paper. A major benefit of the approach is that FE submodels and superelement are treated with the same formalism. The essence of the approach starts by first establishing a master-slave relation between sets of nodes on mating faces, followed by a Delaunay triangulation of the selected master node set, and finally a step where each slave nodal degree of freedom (DOF) is mapped to the DOF's of the three most appropriate master nodes. The method is robust and it has been developed as a support tool for FE modeling and simulation of muliphysics behavior of complex systems. It has been implemented in the general purpose FE software ANSYS as a macro library.Analysis of Dynamic Building Envelope Components by Comparing Experimental and Finite-Element Model ResultsAntonino GiacconeIEREN - Institute for Buildings and Energy SavingsNational Council of Research Palemero - Italy Italo Meroni, Fabio Scamoni
ABSTRACT In this paper, the authors present the results of some experiences made by using ANSYS software which has been suitably employed to assess the behavior of ventilated and breathing external wall systems. Different types of panels and a dynamic window have been realized and submitted to real working conditions for about one year during which the parameters, which have been afterwards used to demonstrate the mathematical model, were recorded. One set of analysis allowed the identification of the most meaningful typology on which the model was then developed. It was believed convenient to rely on a practical tool to be used to assess the different systems typologies under different working and climatic configurations. This is the reason why a mathematical model was studied, optimized and validated on the basis of data obtained from experimentation carried out in real working conditions on the opaque multi-layer system and on the ventilated dynamic window. The results obtained must be considered as particularly interesting, since: The Challenge of Transferring Solid Model Data to ANSYSTony FirminH.G. Engineering Toronto, Ontario, Canada Joe Walsh
ABSTRACT The switch from 2D design to 3D solid modeling is well
underway throughout industry. A dozen different programs are in use for
the creation of 3D design. It is frequently expected that data can be passed
directly to ANSYS for the creation of a finite element mesh. Although the
method of data definition is similar between these programs the quality
of data being transferred leaves much to be desired. This paper will illustrate
some of the problems that have to be dealt with. Techniques have been developed
by ANSYS, FEGS, New Renaissance and others to correct or bypass the problems
as they are encountered. This paper discusses the nature of the difficulties
and some alternatives for fixing the geometry.
Specialized Macros for Model Construction and Loading of Semi-Conductor PackagesBaskaran Bhuvaraghn & Subhendu KunduASIC (India) Texas Instruments (India) Ltd., Bangalore, Karnataka, India Steve Groothuis
ABSTRACT This paper describes two flows that can be used to generate hexagonal mesh from solid models. The first flow discusses the creation of hexagonal mesh from the complete three-dimensional solid model of semiconductor package. The second flow deals with generating a brick mesh from two-dimensional solid model. Each flow has a set of macros. These macros use the geometrical information available from the solid model. Dialog boxes and prompts are created by ANSYS UIDL (User Interface Design Language) and these input mechanisms are used to gather the remaining information. Each flow is unique and employs different techniques to reduce the user intervention and meshing time. Many semiconductor packages have a typical construction, which allows an extrusion method to be used extensively to create the mesh. Therefore, both of the flows focus on automating the extrusion process as much as possible. However, the flows make use of special macros to mesh the parts that are not amenable for extrusion. In the flow that generates mesh from the three-dimensional solid model, the first macro forms the footprint of the solids at the bottom plane. The user can mesh the areas of the footprint using the second macro. The third macro performs the extrusion of these areas to different heights that are extracted from the information available from the solid geometry. After extrusions, two more macros assign the proper material identification to the elements. The material identification is also determined from the solid geometry information available. The external features (e.g., interconnecting leads, solder joints, etc.) are meshed using special purpose macros. In the second flow that creates a three-dimensional mesh
from a two-dimensional geometry, the extrusion process is automated. Unlike
the previous flow, the extrusion height information or material identification
information is not available from the geometry. The user enters this information
and the macros perform the extrusion process for each material in each
extrusion. This flow too has a special macro to create a meshed ball at
any desired keypoint.
Geometry Import techniques of Semi-Conductor Packages from Pro/ENGINEER and AutoCADBaskaran Bhuvaraghn & Subhendu KunduASIC (India) Texas Instruments (India) Ltd., Bangalore, Karnataka, India Steve Groothuis
ABSTRACT Thermal stresses play a vital role in the design of semiconductor IC packages. Accurate evaluation of these stresses is becoming important in their design. Finite Element tools are widely used to calculate the stress levels in the package assemblies. Solid modeling is becoming popular since objects can be represented in an unambiguous way. Pro/ENGINEER is a popular MCAD package to generate solid models. It is a well known fact that three-dimensional analysis using hexagonal (brick) elements are very accurate. However, generating such a Finite Element mesh is time consuming and laborious process. There is a need to reduce the meshing or preprocessing time since a design cycle involves much iteration. This paper outlines the method of generating different semiconductor package assembly in Pro/ENGINEER, transferring the geometry to ANSYS by means of IGES files and then recreating the assembly from the IGES files. The method makes use of Pro/PROGRAM to create multiple versions of package assemblies. Macros are written using APDL (ANSYS Parametric Design Language) to recreate the assembly in ANSYS. UIDL (User Interface Design Language) available in ANSYS is extensively used in these macros to gather the necessary input from the user. AutoCAD is another popular CAD package, which is widely
used to create drawings. From the drawings created in AutoCAD or Pro/ENGINEER,
it may be necessary to generate the finite element mesh. This paper discusses
about the ANSYS macros, which will be used to build the finite element
mesh from the drawings.
Optimisation of DC Electric Arc Furnace Parameters: Optimal Distance Between Bottom Electrodes, Determination of Anode GeometryMilorad Pavlicevic, Alessandro Martinis, Cristina Bassi, and Andrea CoduttiR&D Department Danieli & C, Buttrio, Italy ABSTRACT In a DC electric arc furnace many physical phenomena occur simultaneously and affect each other quite heavily. It is important to study the varying parameters through an interdisciplinary program, like ANSYS Multiphysics, and check them with experimental data. The study presented in this paper was focused on three topics: stirring inside the liquid bath due to the arc current; stirring inside the anode liquid pool and thermal behaviour of electrode. The analysis of the stirring patterns of the liquid metal, both inside the melted bath and the anode pit, involved a three state calculation: electric, magnetic and hydrodynamic. The study was completely three-dimensional in the first case and in part two-dimensional, axis-symmetric in the second. The complete analysis of the anode involved also thermal calculations. In this case the average liquid metal velocity determined with the precedent study was used to set the initial boundary conditions. The paper illustrates also the comparison between numerical
results and data from experimentation. The accuracy of the calculation
can clearly be seen by this comparison.
Numerical Simulation of the Resistance Spot Welding Process Using SpotwelderMartin J. GreitmannState Material Testing Institute (MPA), University of Stuttgart Stuttgart, Germany Klemens Rother
ABSTRACT Resistance Spot Welding is a widely used method to join sheet metal. Different batches of sheet bear the risk of having different physical properties. This is true especially for the very sensitive parameter of contact Resistance. To assure continuous quality and reliability of spot-welds, mainly trial and error techniques have been used. In other cases intitially optimized parameter set-ups are fixed and are used for different batches of sheet metal. The last case especially might produce spot-welds with unacceptable quality, i.e. strength. The quality of spot-welds depends on a lot of different quanties which are dependent on each other, thus coupled: Using SPOTWELDER one can optimize and define the process
relevant parameters of the spot welding machine. SPOTWELDER is a powerful
tool which is easy to use and can be used by quality assurance as well
as design engineers. The analyst gets an inside view of the process zone
using simulation techniques. Some basic examples of resistance spot welding
of aluminum alloys are discussed.
USING ANSYS®â BASED ALUMINUM REDUCTION CELL ENERGY BALANCE MODELS TO ASSIST EFFORTS TO INCREASE LAURALCO'S SMELTER PRODUCTIVITYMarc Dupuis GeniSim Inc.311 Alger St., Jonquiere, Quebec, Canada G7S 2m9 Claude Fradet Lauralco Inc. 1 des Sorces Blvd, Deschambault, Quebec, Canada G0A 1S0 ABSTRACT State of the art ANSYS®â based aluminum reduction cell energy balance models have been successfully used to assist efforts to increase Lauralco's smelter productivity by improving cell thermo-electric design. In this paper, the different models developed are presented
and model validation efforts are described intensively. Initial smelter's
productivity improvements results are presented.
INTEGRAL ANSYS SOFTWARE IMPLEMENTATION FOR MATHEMATICAL SIMULATION OF PIPELINE OBJECTSGennady S. Klishin, Vadim E. Seleznev, and Vladimir V. AleshinJSC "SPE VNIIEF - Volgogaz" Sarov, Nizhny Novgorod reg., Russia ABSTRACTUniversal and wide capabilities and the power of the ANSYS software give the opportunity to implement it for solution of mathematical simulation problems related to the pipeline transport.Works conducted by the JSC "SPE VNIIEF - Volgogaz" resulted in creation of techniques to evaluate the pipelines state from the point of view of their safe operation. The techniques include the methods and algorithms to solve a set of the interconnected problems of magnet dynamics, non-linear structural dynamics that make it possible to evaluate the degree of danger of different pipelines sections. As solvers the techniques use such software as ANSYS, FLOTRAN, LS-DYNA3D, etc. Here ANSYS software plays the main role. ANSYS software allowed us to simulate successfully the accidents leading to the pipeline objects destruction. In this case we conduct complex structural, gas dynamic and thermal calculations that allow us to simulate possible accidents and obtain the real picture of how the accident happened. The area for these techniques implementation: calculations
for the transporting, distributing and field pipelines in gas and oil industry,
for processing pipelines in nuclear power plants.
Q-MORPH: AN INDIRECT APPROACH TO ADVANCING FRONT QUAD MESHING*
Steve J. Owen, Matthew L. Staten, and Scott A. Canann
Canonsburg, PA USA
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