EPMESC VII. International Conference on Enhancement and Promotion of Computational Methods in Engineering and Science, 2–5 August 1999, Macao

732 Pages·1999·40.673 MB·English

by  E. Arantes e Oliveira, J. Bento and E. Pereira (Eds.)

Elsevier Science Internet Homepage
http://www.elsevier.nl (Europe)
http://www.elsevier.com (America)
http://www.elsevier.co.jp (Asia)
Full catalogue information on all books, journals and electronic products.
Elsevier Titles of Related Interest
Mathematics of Finite Elements & Applications
Ed. John Whiteman
ISBN: 0080435688 (Forthcoming)
APCOM'99- 4th Asia Pacific Conference on Computational Mechanics
Ed. K.H. Lee
ISBN: 0080432093 (Forthcoming)
Deformation and Progressive Failure in Geomechanics
Ed. A. Asaoka, T. Adachi, F. Oka
ISBN: 008042838X
CREAM- Cognitive Reliability and Error Analysis Method
Erik Hollnagel
ISBN: 0080428487
Engineering Rock Mechanics: An Introduction to Principles
John A.Hudson & John P. Harrison
ISBN: 0080419127
Related Journals
Free specimen copy gladly sent on request: Elsevier Science Ltd, The Boulevard,
Langford Lane, Kidlington, Oxford, OX5 1GB, UK
Computer Methods in Applied Mechanics and Engineering
Computers and Fluids
Finite Elements in Analysis and Design
Engineering Analysis with Boundary Elements
Advances in Engineering Software
Soil Dynamics and Earthquake Engineering
Computers and Geotechnics
Engineering Failure Analysis
Probabilistic Engineering Mechanics
Reliability Engineering & System Safety
Structural Safety
EPMESC VII
International Conference on Enhancement and Promotion
of Computational Methods in Engineering and Science
2-5 August, 1999, Macao
Volume 1
Edited By
Joâo Bento
E. Arantes e Oliviera
Eduardo Pereira
Instituto Superior Técnico
Lisboa, Portugal
1999
ELSEVIER
Amsterdam · Lausanne · New York · Oxford · Shannon · Singapore · Tokyo
ELSEVIER SCIENCE Ltd
The Boulevard, Langford Lane
Kidlington, Oxford ΟΧ5 1GB, UK
© 1999 Elsevier Science Ltd. All rights reserved.
This work is protected under copyright by Elsevier Science, and the following terms and conditions apply to its use:
Photocopying
Single photocopies of single chapters may be made for personal use as allowed by national copyright laws. Permission of the Publisher
and payment of a fee is required for all other photocopying, including multiple or systematic copying, copying for advertising or
promotional purposes, resale, and all forms of document delivery. Special rates are available for educational institutions that wish to make
photocopies for non-profit educational classroom use.
Permissions may be sought directly from Elsevier Science Rights & Permissions Department, ΡΟ Box 800, Oxford ΟΧ5 1DX, UK;
phone: [phone], fax: [phone], e-mail: [email protected]. You may also contact Rights & Permissions
directly through Elsevier's home page (http://www.elsevier.nl), selecting first 'Customer Support', then 'General Information', then
'Permissions Query Form'.
In the USA, users may clear permissions and make payments through the Copyright Clearance Center, Inc., 222 Rosewood Drive,
Danvers, MA 01923, USA; phone: [phone], fax: [phone], and in the UK through the Copyright Licensing Agency Rapid
Clearance Service (CLARCS), 90 Tottenham Court Road, London W1P OLP, UK; phone: [phone]; fax: [phone].
Other countries may have a local reprographic rights agency for payments.
Derivative Works
Tables of contents may be reproduced for internal circulation, but permission of Elsevier Science is required for external resale or
distribution of such material.
Permission of the Publisher is required for all other derivative works, including compilations and translations.
Electronic Storage or Usage
Permission of the Publisher is required to store or use electronically any material contained in this work, including any chapter or part
of a chapter.
Except as outlined above, no part of this work may be reproduced, stored in a retrieval system or transmitted in any form or by any means,
electronic, mechanical, photocopying, recording or otherwise, without prior written permission of the Publisher.
Address permissions requests to: Elsevier Science Rights & Permissions Department, at the mail, fax and e-mail addresses noted above.
Notice
No responsibility is assumed by the Publisher for any injury and/or damage to persons or property as a matter of products liability,
negligence or otherwise, or from any use or operation of any methods, products, instructions or ideas contained in the material herein.
Because of rapid advances in the medical sciences, in particular, independent verification of diagnoses and drug dosages should be made.
This book has been reproduced in its entirety directly from the original manuscripts of the authors.
First edition 1999
Library of Congress Cataloging in Publication Data
A catalog record from the Library of Congress has been applied for.
British Library Cataloguing in Publication Data
A catalogue record from the British Library has been applied for.
ISBN: 0 08 043570 X HC
@ The paper used in this publication meets the requirements of ANSI/NISO Z39.48-1992 (Permanence of Paper).
Printed in The Netherlands.
NOTE FROM THE EDITORS
The first EPMESC Conference took place in 1985.
As explained several times since then, the idea of the Conference was due to Prof Tadahiko Kawai,
then Professor of the University of Tokyo, and to the first Editor of these proceedings.
The late Prof Luo Songfa, from the South China Institute of Technology, became our Chinese
colleague in the Organising Committee. It will never be too much remembering his enthusiastic
contribution for the organisation of the first EPMESC Conference, and for making it a significant
scientific event in the Region.
The Government of Macao agreed in sponsoring right from the beginning. Dr. Jorge Rangel, then
Secretary for Education (he became later President of the Macao Foundation and, still later, again
member of the Government of Macao), was the highly qualified representative of the Territory
Administration with whom the Committee dialogued since the very beginning.
The first EPMESC Conference could take place, therefore, in the summer of 1985. It was during the
Conference, and recognising the success it had been, that the promoters decided to organise other
EPMESC conferences, giving birth to a new series of international meetings devoted to
computational methods in engineering.
The second Conference was held in the South China Institute of Technology (now called the South
China University of Technology-SCUT), in Guangzhou, the fourth in the Dalian University of
Technology, under the chairmanship of Prof. Zhong Wanxie, and the sixth in the South China
University of Technology, under the chairmanship of Prof. Han Dajian. The University of Macao,
the venue chosen for the first, the third and the fifth, will host also the seventh.
The interest of the Chinese scientific community in these meetings explains in part their remarkable
success.
Special acknowledgements are due, however, to the authorities of Macao, namely His Excellency the
Governor, General Vasco da Rocha Vieira, himself a civil engineer, who was already the Governor
when the 5th EPMESC was held, and the Secretary for Education, Dr. Jorge Rangel, a humanist
who perfectly understands the role of Science and Technology in the development of societies. The
Macao Foundation, presided by Antonio Rodrigues Junior, was the main local funding agency.
A word of acknowledgement is due also to the Territory academic, scientific and cultural
institutions, as well as to other kind of sponsors whose complete list is to be made public during the
Conference. The University of Macao and the Laboratory of Civil Engineering of Macao are the two
best examples to be quoted, for the active support provided to the Organisation from the beginning.
It is amazing how much the Macao scientific and higher education community and system have
progressed since fifteen years ago, when the first EPMESC Conference took place.
Many other changes took place, however.
On one hand, China, the main actor of the EPMESC Conferences, together with Europe, became one
of the great scientific powers of the World. The economical crisis of the Region, which seems to
have spared such a gigantic nation, did not stop its scientific growth.
On the other hand, the global scientific reality, as well as that of the Asia-Pacific Region, have also
changed. For this reason, the acronym EPMESC has now evolved to a more universal meaning.
The variety of subjects covered by the papers submitted to the 7th Conference demonstrates how
much computational methods expanded and became richer in their applications to Science and
Technology. New paradigms are being cultivated as non-numerical applications started to compete
with the more traditional numerical ones. The scientific and technological communities to which the
EPMESC Conferences use to be addressed themselves have changed.
The two-volume Proceedings that we achieved to gather represent many of the interesting
developments that are taking place, not only in the Asia Pacific Region, but also in some other
ν
vi
scientifically advanced parts of the World, and cover a vast list of subjects grouped under the
following headings:
Applied Mathematics
Physics and Materials Science
Solid Mechanics
Finite Element and Boundary Element Methods
Structural Analysis
Structural Dynamics and Earthquake Engineering
Structural Engineering
Reinforced Concrete
Knowledge-Based Systems
Artificial Neural Networks and Genetic Algorithms
Computer-Aided Instruction
Computer-Aided Design and Computer-Aided Engineering
Geographic Information Systems
Environmental Applications
Road Engineering
Geotechnics
Soil Mechanics
Fluid Mechanics and Hydraulics
251 summaries were accepted, many of them with comments and restrictions, by the Programme
Committee.
From these, 153 papers resulted, many of them from Portuguese and Chinese origin, that were
submitted to the revision of an international panel of referees from Australia, Belgium, Brazil,
China, Italy, Macao, Portugal, Switzerland, United Kingdom and United States, to which we gladly
acknowledge our gratitude and appreciation.
We are happy to say that the reviewing process, although having to be done within the short time
frame available, was quite successful and contributed a lot to the high quality that the Organising
Committee aimed to attain. Some papers were deeply changed by their authors, according to the
referees' comments. Some others had, unfortunately, to be rejected.
In what concerns the keynote lecturers, whose choice certainly is one of the most important factors
of success in any scientific conference, a great care was put in inviting them. Invitations were
addressed to eminent professors, from China, Europe, the United States, Australia and Japan. It is
for us a great honour and pleasure that almost all of them accepted to co-operate. Their presence in
Macao will ensure that the aims of the Organising Committee will be met.
E. Arantes e Oliveira Joâo Bento Eduardo Pereira
PREFACE
In his famous work entitled The Decline of the West, published shortly after the 1st World War,
Oswald Spengler included, as one of its main ideas, a refusal to see modern science as a continuation
or perfectionning of ancient science. The latter was, according to Spengler, a creation of a different
nature, as, for example, modern art is different from ancient art. Each one reached, like art itself, its
ideal point of perfection.
In other words, modern European science was a creation of the Renaissance and so, although using
medieval philosophy as an intellectual crutch, a late creation by Western culture.
Thus, why would other civilisations adopt as theirs this kind of science and transform it into an
adjectiveless Science, instead of using their own scientific systems ?
Wouldn't it have been because such a kind of knowledge could have technological consequences
which, when used, could make it possible the solution of problems which were or became, in all
these societies, similar to the West's ?
The need for social-economic development depends, obviously, on the structure of the societies,
their aims, their spiritual values, their human and natural resources and the problems they intend to
solve. In some cases, Western scientific knowledge was used by other civilisations having as their
aims such goals that had nothing to do with the ideals which had given the inspiration for its
development.
However, the impact which resulted from the encounters, not always peaceful, of the different
civilisations with Western civilisation, the fact that Europe became politically dominant, for a while,
in a huge proportion of the Globe, the seduction of success when achieved, and the fact that the
amount of communication established between the different parts of the Globe brought to the
surface new and analogous problems throughout the Earth, had the result, for every society, of
producing a need for those technologies which only the West possessed.
In more recent times, the tendency to use these technologies was brought about, in certain non-
Western countries, mainly in Eastern Asia, by the need to compete and position themselves in other
continent's markets.
There could have been few cases, thus, in which Technology wasn't the vehicle used for the Western
scientific system to merge into the heart of the remaining civilisations.
However, the majority of times, the West gave its techniques without giving its knowledge, at least
to permit those in the receiving to develop it.
The promoters of the EPMESC series of conferences, both from the Asia Pacific Region and from
the West, were aware of these facts. The EPMESC project was thus aimed to promote scientific
methods in the Asia Pacific Region. And the EPMESC meetings were successful enough to become,
at least in the broad area of computational methods in engineering, the longest series of international
conferences in the Region.
The EPMESC Conferences were initially devoted to the Education, Practice and Promotion of
Computational Methods in Engineering Using Small Computers. These objectives, which were
deemed adequate in 1985, when the series started, have later been extended to accommodate the
evolution of technology and the generalisation of the use of computational tools to a broader range
of scientific fields. The emphasis became thus associated, under the same acronym, to the
Enhancement and Promotion of Computational Methods in Engineering and Science.
*
The first EPMESC Conference was held in Macao in 1985. Since then, the Conferences have been
held alternatively in Macao and in mainland China.
It was in 1557 that the Portuguese settled in Macao. China was then the most important country in
the World and the Europeans came to China with feelings of respect and admiration.
vii
viii
The Territory of Macao was thus not taken by force. It was graciously granted by the great Central
Empire to serve as a base for merchants and missionary/scientists whose activity was regarded with
great interest by China. Portugal, the strange and semi-barbarian (as seen by Chinese) Ta Si Yan
Kuo, the Country of the Western Ocean, was useful to China, and the Chinese pragmatism prevailed
upon any other feeling or consideration.
The Portuguese, pragmatic as well, remained in Macao, wisely avoiding understand too clearly
which was the statute assigned to them. The best definition of the traditional statute of Macao is
perhaps the one given by the 1976 Portuguese Constitution: a Chinese Territory under Portuguese
Administration.
Under the long lasting Portuguese administration, Macao, which was once compared to Venice as a
kind of city-state, knew highly prosperous periods, particularly when it served as a link between
China and Japan.
The city was strongly affected by the isolation of Japan under the Tokugawa. Subsequently, the
rise of Hong Kong drove the Territory to an increasing oblivion, transforming it almost into an
interesting historical relic.
But, about twenty years ago, following the example of most countries in the Region, Macao
initiated a new cycle of economic prosperity and became again what had been before: a door
between China and the Western World.
*
The appearance of computers in the middle of the 20th Century caused in Science and Engineering
what can be called the second revolution (the first being launched by the use of Science in
Engineering).
The new possibilities, enabling engineers to make more extensive use of existing scientific tools,
allowed them also to access to fields that had previously been considered to lie outside their sphere
of interest.
On the other hand, computers brought with them another possibility: that of computing
automation. Making it necessary the modelling and programming of analysis, computing-automation
raised problems, however, that simply did not exist before the advent of computers.
In an article published in 1964, Charles Miller, then Head of the Civil Engineering Department of
the MIT, made an analysis - now historic - of the perverse effects that the use of computers was
then having on civil engineering.
His accurate criticisms were partly overcome by the extraordinary development of the machines,
particularly in what concerned capacity and speed.
From their side, computer scientists answered the challenge by developing non-numerical
computational techniques that are being spread among engineers and scientists. The modelling of
knowledge-based processes and, in particular, its modelling within an engineering environment, may
be said to correspond to a recent endeavour, largely resulting from the extension of early attempts to
enhance computer-aided engineering tasks confusingly gathered under the CAE acronym.
EPMESC Conferences series is long enough to make it clear how this evolution has taken place, and
the organisers of the present Conference are proud that a large number of papers on non-numerical
computational methods have been included in the present proceedings.
*
In December 1999, shortly after the Vllth EPMESC Conference, Macao will cease to be a Chinese
Territory under Portuguese Administration to become a Chinese Territory under Chinese
Administration.
Such major political change may represent a stimulus for Macao to reinforce its role as a traditional
meeting point between Eastern and Western cultures.
ix
With its calm atmosphere, its young University and modern scientific institutions, the specificity of
its culture, its excellent infrastructures, Macao may namely become one of the favourite places in
China for hosting international scientific meetings.
The Chairman of the EPMESC VII Organising Committee
Eduardo R. de Arantes e Oliveira
To Contact the Publisher
Elsevier Science welcomes enquiries concerning publishing proposals; books, journals
special issues, conference proceedings etc. All formats and media can be accommodated.
Should you have a publishing proposal you wish to discuss, please contact, without
obligation, the publisher responsible for Elsevier's civil and structural engineering publishing
programme;
Dr. Jim Hough
Publishing Editor
Materials Science and Engineering
Elsevier Science Ltd
The Boulevard, Langford Lane Phone: [phone]
Kidlington, Oxford Fax: [phone]
0X5 1GB, UK E-mail: [email protected]
General enquiries including placing orders, should be directed to Elsevier's Regional Sales
Offices- please access the Elsevier homepage for full contact details.
FINITE ELEMEN T MODELLIN G
OF CONTINUOU S CASTIN G
S. Cescotto 1, A.M . Habraken1, F . Pascon1, F . Labory2 and M. Bourdouxhe2
1 University of Liège, MS M Department, Belgium
2 ARBE D Research and Development, Luxembourg
ABSTRACT
The surfac e and internal quality of continuous cast semis depends very much on the behaviour
of th e strand in the mould. The mould taper is one of the most important parameters likely to
influence it. In order to understand and to predict this behaviour, we have developed a finite
element mode l that should lead us to determine the thermal shrinkage of the strand and the
stress an d strain fields in the solidified shell. This paper presents our assumptions and the
different tool s that we have developed especially for this model. The final results are not
already achieve d with this complete model, but a simpler model has already provided results.
These firs t results allowed us to define the taper of the mould so that the thermal exchange
conditions ar e improved.
KEYWORDS
continuous casting , mould taper, modelling, finite element
INTRODUCTION
It is well known that, among the parameters likely to influence the breakouts or the surface
and th e internal quality of the continuous cast semis, the mould taper takes a prominent part.
Up t o now, physical phenomena involved in the continuous casters are not totally known or
understood, i n spite of all the past and current researches on the topic.
However, th e steel producer has to determine as accurately as possible the taper of his moulds
for the continuous casting of his semis. This determination is usually carried out empirically
or b y using a mathematical model.
3
4
For the totally convex cross sections like blooms or billets, the taper is positive on the whole
outline. In this case, the consequences of a taper that is too low are a loss of contact and a gap
between the strand and the mould. The thermal exchange and the shell growth decrease
dramatically, the section can get out of shape and the product can be affected by surface or
subsurface defects or even breakouts. The consequence of a taper that is too high is friction
between the strand and the mould, inducing stresses and strains in the solidifying shell. Like
in above case, the consequences can be surface or subsurface defects or breakouts.
For more complex cross sections showing a partly concave outline, like a beam blank for
instance, the taper can be negative on a part of the outline. For a negative taper, a value that is
too low leads to friction between the strand and the mould, inducing stresses and strains in the
solidifying shell, and a value that is too high leads to a loss of contact and an insufficient
thermal exchange and shell growth. In both cases, the consequences can be defects or
breakouts.
The goal of this study is to model the solidification of a 125 mm χ 125 mm billet in a mould
the taper of which is equal to 0.65625 mm/m (see Figure 1).
125 mm
A Ζ
700 mm
600 mm
LIQUID STEEL SECONDARY COOLING
(WATER SPRAY)
MUSHY ZONE
SOLIDIFIED SHELL
Figure 1 : Strand in the mould
We only deal with the first part of the cast (primary cooling), when the strand is still in the
mould. The next part (secondary cooling by water spray), after the exit of the mould, needs
another model that is not the topic of this paper.
GENERAL MODEL DESCRIPTION
The models are based on a finite element method and more specifically on the non linear code
LAG AMINE developed in University of Lièg e by the team of professor S. Cescotto since
1982. Able to simulate various forming processes, this code takes into account non linear
phenomena a s large strains, large displacements or rotations, various non linear constitutive
laws, contact and friction. Staggered or fully coupled thermo-mechanical analysis are