aau esbjerg - subsea workshop 080213(1)

5/27/2018 AAU Esbjerg - SubSea Workshop 080213(1)

1/54

Esbjerg, Friday 8th February 2013

Conference and workshopUnderwater robots

Offshore structures and structural behavior due tobiofouling


2/54

www.aau.dk

www.esbjerg.aau.dk

Presentation Anders Schmidt Kristensen

M.Sc. in Mechanical Eng. from Aalborg University in 1993 Ph.D. in Mechanical Eng. from Aalborg University in 1997

Consultant for PTC Denmark 1997-1998 implementationof Pro/ENGINEER

1998 to pt. Associate Prof. at Aalborg University Esbjerg inMechanical Engineering

Associate Prof. Mechanical Engineering, Ph.D., M.Sc. (ME),

Department of Civil Engineering, Aalborg UniversityEsbjerg

2010 Head of Campus Esbjerg


3/54

www.aau.dk

www.esbjerg.aau.dk

Finite Element Modelling


4/54

www.aau.dk

www.esbjerg.aau.dk

Aalborg University (AAU)

AAU-Esbjerg

AAU-Cph

197.426 mennesker i Aalborg Kommune pr. 1 januar 2010

115.114 mennesker i Esbjerg Kommune pr. 1 januar 2010


5/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures and structural behavior due

to biofouling

Motivation Offshore structures

Examples

Structural behavior

Loads

Fatigue Biofouling or marine growth

5


6/54

www.aau.dk

www.esbjerg.aau.dk

Motivation

Biofouling or marine growth is found to influenceloading of offshore structures by increasing tubediameters, drag coefficient, mass and hydrodynamic

added mass and structural weight. Biofouling or marine growth obstruct service and

inspection of offshore structures.

6


7/54

www.aau.dk

www.esbjerg.aau.dk

Motivation - continuedObjective 2.1: Cognitive Systems and Robotics

Target outcomes

a) Robotic systems operating in real-world environments: Expanding and improving the functionalities ofrobotic systems and further developing relevant features, such as autonomy, safety, robustness, efficiency, andease of use. As appropriate, work will include exploring ways of integrating, in robotic systems, new materials andadvanced sensor, actuator, effector and leading edge memory and control technologies.

Expected impact

Integrated and consolidated scientific foundations for engineering cognitive systems under a variety ofphysical instantiations.

Significant increase in the quality of service of such systems and of their sustainability in terms of, forinstance, energy consumption, usability and serviceability, through the integration of cognitive capabilities.

Innovation capacity in a wide range of application domains through the integration of cognitive capabilities.

Improved competitive position of the robotics industry in existing and emerging markets for instance in thefollowing sectors: manufacturing; professional and domestic services; assistance and co-working, production,logistics and transport, construction, maintenance and repair, search and rescue, exploration and inspection,systems monitoring and control, consumer robotics, education and entertainment.

Consensus by industry on the need (or not) for particular standards. More widely accepted benchmarks.Strengthened links between industry and academia.

7


8/54

www.aau.dk

www.esbjerg.aau.dk

Motivation

Increasing activities in installations: Offshore structures

SubSea systems and installations

Deep Sea/Deep Water systems

Services:

Surveillance Maintenance

Inspection

Decommissioning 8


9/54

www.aau.dk

www.esbjerg.aau.dk

Subsea systems and installations

API RP 17N, Recommended Practice for Subsea Production System Reliability and Technical Risk Management.

API RP 17A 4th Ed 2006 - Recommended Practice for Design and Operation of Subsea Production Systems equal to ISO13628-1

API RP 17B 4th Ed 2008 - Recommended Practice for Flexible Pipe equal to ISO 13628-11 API RP 17C 2nd Ed 2002 - Recommended Practice on TFL (Through Flowline) Systems equal to ISO 13628-3

API SPEC 17D 1st Ed 1992 - Specification for Subsea Wellhead and Christmas Tree Equipment API SPEC 17E 3rd Ed 2003 - Specification for Subsea Production Control Umbilicals

API SPEC 17F 1st Ed 2003 - Specification for Subsea Production Control Systems equal to ISO 13628-6 API RP 17G 2nd Ed 2006 - Recommended Practice for Design and Operation of Completion / Workover Riser Systems API RP 17H 1st Ed 2009 - Recommended Practice for Remotely Operated Vehicles (ROV) Interfaces on Subsea equal to

ISO 13628-8 API RP 17I 1st Ed 1996 - Installation Guideline for Subsea Ambilicals API SPEC 17J 2nd Ed 1999 - Specification for Unbonded Flexible Pipe equal to ISO 13628-2 API SPEC 17K 1st Ed 2001 - Specification for Bonded Flexible Pipe equal to ISO 13628-10

API RP 17M 1st Ed 2009 - Recommended Practices on Remotely Operated Tool (ROT) Intervention Systems equal to ISO13628-9

API RP 17N 1st Ed 2009 - Recommended Practice for Subsea Production System Reliability and Technical Risk Management API RP 17O 1st Ed 2009 - Recommended Practice for Subsea High Integrity Pressure Protection Systems (HIPPS)

9


10/54

www.aau.dk

www.esbjerg.aau.dk

SubSea systems and installations

10


11/54

www.aau.dk

www.esbjerg.aau.dk

OFFSHORE STRUCTURES

11


12/54

www.aau.dk

www.esbjerg.aau.dk

Terminology

12


13/54

www.aau.dk

www.esbjerg.aau.dk

Offshore systems

13


14/54

www.aau.dk

www.esbjerg.aau.dk

Offshore systems

14

WILL ALSO AFFECT INFRASTRUCTURE


15/54

www.aau.dk

www.esbjerg.aau.dk

Offshore systems

15


16/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

- Jacket foundation

16


17/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

17


18/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

18


19/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

19


20/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

20


21/54

www.aau.dk

www.esbjerg.aau.dk

Installation

21


22/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

22


23/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

23


24/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures monopile foundation

24


25/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures monopile foundation

25


26/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structures

26


27/54

www.aau.dk

www.esbjerg.aau.dk

STRUCTURAL BEHAVIOR

27


28/54

www.aau.dk

www.esbjerg.aau.dk

Residual stress are built-in or introduced (typically duringmanufacturing) to an unloaded part.

Residual stresses can be the cause of crack initiation and,therefore, fatigue failure

Source: ASM International

Example: rotary dryer. Weldinglifters to a rotary shell

Residualstressesintroduced

during weldingcaused crackinitiation

Fatigue failure Residual stresses


29/54

www.aau.dk

www.esbjerg.aau.dk

Fatigue failures

Samlinger

Alexander L. Kielland (1980)Accomm / drilling rigLess than 2 years oldCapsized when member failed due to fatigueCapsized in under 20min123 died


30/54

www.aau.dk

www.esbjerg.aau.dk

Fatigue failures

Samlinger


31/54

www.aau.dk

www.esbjerg.aau.dk

Offshore wind energy systems

31


32/54

www.aau.dk

www.esbjerg.aau.dk

Loads

32


33/54

www.aau.dk

www.esbjerg.aau.dk

Loads

Random loads can bedescribed in the Timeor Frequency domain:

Introduction

33


34/54

www.aau.dk

www.esbjerg.aau.dk

Introduction

34

Characterization of Fatigue

Fatigue - a distinct failure mode: Apparently brittle even in ductile materials

Sudden and catastrophic

Result of initiation and propagation of a crack

Fatigue is failure due to time-varying stresses


35/54

www.aau.dk

www.esbjerg.aau.dk

Introduction

35

Fatigue failure

Fatigue failures more common than static Due to multiple loadings of material

Always begins at crack

Occurs in three stages Crack initiation

Crack propagation Fracture


36/54

www.aau.dk

www.esbjerg.aau.dk

Introduction

36

Fatigue failure


37/54

www.aau.dk

www.esbjerg.aau.dk

Damage ratio D

Stress-life


38/54

www.aau.dk

www.esbjerg.aau.dk

Introduction

5x105 = 500.000 cykler 2x106 = 2.000.000 cykler


39/54

www.aau.dk

www.esbjerg.aau.dk

39

Fatigue issues


40/54

www.aau.dk

www.esbjerg.aau.dk

Fatigue issues

40


41/54

www.aau.dk

www.esbjerg.aau.dk

Offshore structural components

41


42/54

www.aau.dk

www.esbjerg.aau.dk


42


43/54

www.aau.dk

www.esbjerg.aau.dk

TOWER = 150.000kg

43

En reduktion afgodstykkelsen p1 mm betyder envgt besparelse

P 2 tons

En reduktion afgodstykkelsen p1 mm betyder envgt besparelseP 3,8 tons

34m

17m

Estimated 16 mill dkr saved for 90 OWT


44/54

www.aau.dk

www.esbjerg.aau.dk


44


45/54

www.aau.dk

www.esbjerg.aau.dk

BIOFOULING OR MARINE

GROWTH

45


46/54

www.aau.dk

www.esbjerg.aau.dk

Problem description:

Biofouling/marine growth is an accumulation ofmicroorganisms, plants, algae, and/or animals

on wet or wetted surfaces.

46

Marine growth can increase the radius of a windturbinefoundation upto 25cm. This results in:

- Inspection is made difficult, i.e. fatigue, corrosion- Loads are increased, i.e. hydrodynamics forces- Corrosion is increasedResulting in:- Increased costs of systems production- Increased costs of maintenance/operation- Increased costs of inspection


47/54

www.aau.dk

www.esbjerg.aau.dk

Problem description:

47


48/54

www.aau.dk

www.esbjerg.aau.dk

Citations from Offshore Windturbine regulations:

48


49/54

www.aau.dk

www.esbjerg.aau.dk

Definitions:

49


50/54

www.aau.dk

www.esbjerg.aau.dk

Basic components in an Autonomous Underwater Vehicle (AUV)

50

FRAME

BUOYANCYCONTROLSYSTEMS

PROPULSIONSYSTEMS

DEPLOYMENTSYSTEM

DOCKINGSYSTEM

MANIPULATORSYSTEM

BIOFOULING

Need: Biofouling causes an increase of loads on an offshore windturbine, i.e. increased costs.

Problem: Can an offshore structure be kept free of biofouling using an AUV system?


51/54

www.aau.dk

www.esbjerg.aau.dk

Example on an Offshore Wind Farm:

51

AUV visiting all Wind turbines

to remove marine growth

dk


52/54

www.aau.dk

www.esbjerg.aau.dk

Example - cost

52

www aau dk


53/54

www.aau.dk

www.esbjerg.aau.dk

Issues to be solved:

Deployment How do we put/install the system in the water?

Buoyancy How do we design a buoyancy system without affecting thehydrodynamics of the vehicle/vessel?

Docking How do we supply the vehicle/vessel with energy during operation? Propulsion How do we design the propulsion system to allow minimum use of

power and to maximize maneuvering? Frame - How do we design a frame without affecting the hydrodynamics of the

vehicle/vessel? Manipulator How do we design a system which allows us to hook on/off the

offshore structure and remove/clean biofouling with a minimum use of power?

Control How do we navigate between several offshore structures, how do wenavigate into the docking unit and dock/undock, how do we operate the cleaningprocess?

53


54/54

Thank you for your attention

aau esbjerg - subsea workshop 080213(1)

Documents