Proceedings of the International Workshop Environmental Loading on Offshore Structures, Universidada da Beira Interior, Portugal, Covilha, October 28-29, 1997 (summary)

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Z International Workshop

!> I S § I E n v i r o n m e n t a l L o a d i n g

Offshore Structures

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Covilha6200 PORTUGAL

Proceedings of the Intemational Workshop

Environmental Loading

on

Offshore Structures

Editor: Antonio C. Mendes

Sponsored by:

EC COPERNICUS, Grant ERB CIPA CT-940150 AGARD

Conference Organisers

Chairman •

Manuel J. Santos Silva Rector o f Universidade da Beira Interior, Covilha (Portugal)

Members

Antonio C. Mendes José C. Pascoa Kostadin Yossifov Georgi Georgiev

UBI-Laboratory o f Fluid Mechanics, Covilha (Portugal) UBI-Laboratory o f Fluid Mechanics, Covilha (Portugal) Bulgarian Ship Hydrodynamics Center, Varna (Bulgaria) Ship Research & Design Division, Varna Shipyard (Bulgaria)

Scientific Committee

Antonio C. Mendes UBI-Laboratory o f Fluid Mechanics, Covilha (Portugal) Candido P. Morgado Universidade Católica, Figueira da Foz (Portugal) Jan A. Kolodziej Technical University o f Poznan. Poznan (Portugal) Roumen Kishev Bulgarian Ship Hydrodynamics Center, Varna (Bulgaria) Stefan Tomchev Ship Research & Design Division, Varna Shipyard (Bulgaria)

Invited Speakers

John R. Chaplin City University, London ( U K )

Antonio F. Falcao Instituto Superior Técnico, Lisbon (Portugal)

F O R E W O R D

For the past three years six institutions have been in close contact performing a joint research on the analysis and design of the offshore structures within the frames of Project ERB CIPA CT-940150 belonging to the COPERNICUS Programme.

In accordance with the spirit of the COPERNICUS imtiative, in the realisation of the Project involved are research teams from both the West and East European countries such as the UK, Portugal, Poland and Bulgaria.

The research teams have been recruited from the institutions renewed for their expertise in the analysis, design and manufacture of off-shore structures. Apart from the City University, represented by Professor John Chaplin whose scientific collaboration in the project is highly appreciated, the other participants are:

• the University of Beira hiterior;

• the Technical University of Poznan (Poland);

• the histimte of Fundamental Technological Research of Warszawa (Poland); • the Varna Shipyard (Bulgaria);

• the Bulgarian Ship Hydrodynamics Centre (Bulgaria).

Tlie total budget of the Project amounts to 335 thousand ECU. The results of the research carried out on the project, obtained so far, give good grounds for applying for a renewal of the contract for the next three years.

The three years of common research carried out by the Poznan Technical University, the City University and U.B.I, enabled us to establish close ties which may be helpful in developing a co-operation in other fields of academic activity. The University of Beira Interior would be particularly interested in creating common post-graduate studies in Civil, Mechanical and Aeronautical Engineering, as well as in receiving external assistance in developing its new Hydrodynamics Laboratory, whose facilities could be used later for conducting research projects by the staff of foreign institutions.

We are also interested in a broad exchange of scientific and didactic staff, and ©n the exchange of students, in accordance with the European Training and Mobility and the Socrates Prograrrunes.

Establishing a closer co-operation between all partners of this project can be our small contribution to the implementation of the idea of a new, united Europe.

On behalf of the organising committee of this meeting I would like to welcome all participants in the workshop and hope that, all together, we can give another step to the implementation of the idea of a new. united Europe.

Covilha, 27'" October 1997 The Rector of U.B.L

Prof. Dr. MaïïCiel José dos Santos Silva

P R E F A C E

The Intemational Workshop on Environmental Loading on Offshore Structures brings together specialists from six parmer institutions for a plenar>' meeting o f EC Project COPERMCUS ERB CIPA CT-940150 ''Design of Adaptive Offshore Structures Under Extreme Wave Loading'.

The meeting summarises two and a half years of research activities carried out on the numerical implementation and experimental verification of the waves and current loading simulator on a model of offshore jacket, under extreme environmental conditions. The research involves the assessment of overall loadmg as well as internal stresses on the physical model, oriented towards the analysis and optimal design of skeletal structures equipped with dissipating devices.

Along with the working sessions of the meeting two mvited speakers will conduct general review lectures in areas which are very much up to date, in connection with the energy ofthe ocean waves and the hydrodynamic damping of offshore structures.

As coordinator of the Project I would like to acknowledge the valuable collaboration of all the research teams involved in this joint research effort, as well as the financial support received so far from the European Commission and the consultant missions that were provided by AGARD.

Covilha, October 1997 The Editor

Prof. Antonio Carlos Mendes

TABLE OF CONTENTS

Invited Paper

J.R. Chaplin, ''Hydrodynamic Damping of Cylinders in Still Water, in Currents and in

Oscillatory Flow'" 6

Session Papers

A.C. Mendes, "Design of Adaptive Offshore Structures Under Extreme Wave Loading:

Lay-out of the Projec f 16

R. Kishev, D. Radev, V. Rakitn, "Systematic Experimental Investigations of

Hydrodynamic Loading on a Jacket Platform" 25

Z. Shinev, S. Tomchev, "Model Design Features for Experimental Investigations of

Offshore Platform Subjected to Wave Loading" 42

A. Uscilowska, J.A. Kolodziej, A.C. Mendes, "Non-Linear Dynamics of An

Articulated Tower Under Wave Loading: Computer Simulation of Motion" 50

L. Knap, J. Holnicki-Szulc, "Design of Adaptive Structures for Extreme Loading" 66 R. Starosta, A.C. Mendes, J. A. Kolodziej, "Computational Prediction and

Experimental Determination of The Wave Forces Acting Upon a Model of Truss

Structure" 77

Conclusions of the Workshop 91

Acknowledgements 92 List of Participants 93