session 32 olle rutgersson

Chalmers University of Technology

Department of Shipping and Marine TechnologyTransportforum in Linköping, January 8-9, 2009

JW Ringsberg and O Rutgersson

Multidisciplinary research –a necessity in the developmentof future class rules

Professor Olle Rutgersson andAssociate Professor Jonas Ringsberg

Department of Shipping and Marine TechnologyChalmers University of Technology




Outline

• Introduction• The Safecoll project – innovative design• The Hasard project – a holistic model for damage stability

assessment• Concluding remarks




Competence areasMaritime law

Economics

Logistics & cargo

Structural engineeringHydromechanics

Operation & safety

Environment

Human factors

Education programs

Systems engineering

Research and education




Organisation and personnelHead of Department Olle Rutgersson

Division of Ship DesignHead of division: Jonas Ringsberg

• Marine Structures• Marine Transport Systems• Seakeeping

Division of Ship Work Environment and SafetyHead of division: Margareta Lützhöft

• Human Factors• Maritime Safety• Navigation and Communication

Division of Shipping Logistics and CharteringHead of division: Anneli Rask

Division of Sustainable Ship PropulsionHead of division: Lars Larsson

• Hydromechanics• Marine Environmental

Technology• Marine Machinery Systems

Maritime WaypointLars-Eric Carlsson

• Market of Shipping• External Courses• Full-mission Bridge Simulator

AdministrationBirgitta Oscár

Vice Head of DepartmentLars LarssonDeputy Head of DepartmentEva JacobssonResearch CoordinatorBjörn Södahl




Introduction

• The Safecoll project– An investigation of maritime safety when collision between two

ships occurs.– Development of a new “innovative” side-shell structure which allows

for large intrusion depth before leakage occurs.

• The Hasard project– Development of tools and models using a holistic approach.– A joint project between the disciplines of marine structures and

seakeeping.




The Safecoll project

• Safecoll:– Safety against collisions by means of innovative side shell designs.– Project leader: Professor Anders Ulfvarson.

• Project aims:– To achieve improved collision safety for collisions that take place in the side of

the struck ship (focus on RoPax ships).– The mass of the new (proposed) structural design should be maintained or

reduced in comparison with existing conventional structural designs.

• The Safecoll project was funded by:– VINNOVA, – The Swedish Mercantile Marine Foundation and – The Swedish Maritime Administration.




Requirements on the new side-shell design

• Stakeholders’ interests must be fulfilled(the shipowners, the classification societies and maritime authorities, the shipyards, insurance companies and the cargo owners)

• A 100% increase of the energy absorption capability of the side-shell structure.

• A cost increase of a maximum of 1.5% of the ship’s total cost.• A weight increase of a maximum of 1.5% of the ship’s total

lightweight.• An unchanged cargo and ballast volume.• Normal structural strength according to the rules.• Access for inspection and maintenance.• Not a “too complicated” design to construct.




Deformable inner side-shell against collision damage

Ship-to-ship collision Collision damage caused by a bulbous bow colliding into the side of a ship




The reference vessel “Intermodeship” and themidship section used in the FE-simulations

Length overall: 88 mBredth molded: 13.3 mDesign draught: 4 m 10.75 m

16.80 m

Schematic illustration of the deformable inner side-shell

The reference vessel “Intermodeship” and themidship section used in the FE-simulations

Deformable inner side-shell

Waterline




The “steel sheet test” Nonlinear explicit FEA of the test

0

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Indenter displacement [m]

Forc

e [M

N]

Test 240_1Test 240_2Test 355_1Test 355_2Test 700Mtrl 240, Shear failure 45%Mtrl 355, Shear failure 45%Mtrl 700, Shear failure 39%




Experiments and nonlinear explicit FEA of a scaled ship structure

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Test structure 1Test structure 2Mesh 15mm, failure strain 39%

Penetration of the upper plate.

Test FEM

Penetration of the lower plate.

Test FEM

Test FEM

T-beam off.




Comparison of nonlinear explicit FEA between a full-scale (conventional) ship structure and a new design

CL CL6675 mm 6675 mm

Waterline at design draught

Conceptual designReference design

54321

Main deck

Tanktop

A B

4800 mm

Waterline at design draught

CL6675 mm

B/5

Referencedesign

Conceptualdesign




The Hasard project

• Hasard:– Holistic assessment of ship survivability and risk after damage.– Project leader: Associate Professor Jonas Ringsberg.

• Project aims:– To outline a comprehensive calculation procedure which quantitatively can

be used for study of ship’s survivability caused by collision damage, incorporating:

• structural collision resistance,• structural stability and collapse, and• ship flooding and stability in waves.

• The Hasard project is funded by:– VINNOVA and– Lighthouse.




HASARD/SEAKEEPING

HASARD/SEAKEEPING

Damage patterns on the hull for various collision scenarios

HASARD/MARINE STRUCTURES

HASARD/MARINE STRUCTURES

SIMCAP

Global loads

Local loadsRisk analysis

Updated ship stability conditions and loads acting on the structure

FEA




Uniaxial tensile test(FEA and experiments)

FLD + biaxial tests(FEA and experiments)

Ship structure in small scale(FEA och experiments)

Large (global) ship structures(Prediction/study by FEA, study of known accidents)

MARINE STRUCTURES: Methodology for the development and validation of numerical models




Example of a damage pattern used as input to the SIMCAP code




SEAKEEPING: Damage stability calculations using the SIMCAP computation code

Water on deck!MV Estonia

DESSO




Holistic approach –marine structures and seakeeping

• A procedure has been developed to transfer the geometry of arbitrary side-shell damage from a finite element analysis to the SIMCAP code.

• SIMCAP can be used for the analysis of arbitrary wave directions.– Progressive flooding is under implementation.

• The approach has to some extent been validated against availableexperimental model tests (Estonia research project).

• A number of serious collision scenarios for different ships in calm sea and harsh weather with waves and wind effects is studied.– Study sensitivity for structural design modifications.

• Risk analysis:– Work has started and will be completed during 2009.




Size of damage:

L (1:1) 39.25 m2

M (1:2) 9.81 m2

S (1:4) 2.45 m2

Resolution of damage in the model:

MD 157 pts

HD 571 pts

LD 1 pts

Location of damage:

Sub KL+3 m

WL KL+5 m

Above KL+6 m

Influence from location and size of damage




Flooding through a rectangular hole (bow ramp opening) with different headings and speeds (example study)

Simulation of flooding (the Estonia research project)




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9015knot head seas

time [s]

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905 knot head seas

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Speed variation

15 knots

10 knots

5 knots




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9015 knot 15 deg SB seas

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Heading variation




Time to flood 5000 tonnes on car deck

050

100150200250300350400450

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vessel speed [knots]

time

[s] head seas

15 deg SB seas30 deg SB seas45 deg SB seas

Example of presentation of results




Concluding remarks …

• Development of future class rules requires multidisciplinary research activities between– academia and industry, and– different research groups and universities.

• Holistic models may serve as virtual tools/laboratories which can assist in rule making by empirical analysis and probability-based design.

• More information about the Hasard and Safecoll projects: http://www.chalmers.se/smt/EN/research

Founder LIGHTHOUSE MARITIME COMPETENCE CENTRE

Thank you!

session 32 olle rutgersson

Business