ABSTRACT
ISSC committee V.6: ARCTIC TECHNOLOGY 811
ISSC committee V.6: ARCTIC TECHNOLOGY 813
ISSC committee V.6: ARCTIC TECHNOLOGY 815 POLARSTERN 1984
COMMITTEE MANDATE Concern for the structural longevity of ship, offshore and other marine structures. This shall include diagnosis and prognosis of structural health, prevention of structural failures such as corrosion and fatigue, and structural rehabilitation. Attention should be given to ongoing lifetime extension of existing structures. Focus shall be on methodologies for translating monitoring data into operational advice and lifecycle management. The research and development in passive, latent and active systems including their sensors and actuators should be addressed. Further, self-healing and smart materials should be addressed. COMMITTEE MEMBERS Chairman: P. Hess, USA (Chair)
S. Aksu, Australia J.I.R. Blake, UK D. Boote, Italy P. Caridis, Greece A. Egorov, Ukraine A. Fjeldstad, Norway M. Hoogeland, Netherlands H. Murayama, Japan M. Rye Anderson, Denmark M. Tammer, Netherlands
KEYWORDS Ship structures, fatigue, service life, corrosion, structural health monitoring, structural longevity, structural inspection, structural repair, structural maintenance, structural damage detection, fatigue life, crack detection, structural lifecycle assessment, structural lifecycle management, structural sensing, acoustic emission
818 ISSC committee V.7: STRUCTURAL LONGEVITY CONTENTS
1. INTRODUCTION 820 1.1 Background & Mandate 820 1.2 Relationship with other ISSC Committees 820
2. LIFECYCLE ASSESSMENT & MANAGEMENT FOR STRUCTURAL LONGEVITY 821 2.1 Introduction 821 2.2 The Need for Lifecycle Assessment and Management 821 2.3 Conclusions 823
3. CURRENT PRACTICE 823 3.1 Introduction 823 3.2 The Role of Regulators and Classification Societies 823 3.3 Classification Rules and Guidance 824 3.4 Commercial shipping vessels 825
3.4.1 International trading vessels 825 3.4.2 High-speed Craft (HSC) 826 3.4.3 Vessels operating in inland waterways 826
3.5 Offshore structures 826 3.5.1 Offshore drilling units 826 3.5.2 Floating Production Storage and Offloading (FPSO) units 827 3.5.3 Fixed production platforms 827
3.6 Naval vessels 827 3.7 Conclusions 828
4. PREDICTION OF LONGEVITY 828 4.1 Introduction 828 4.2 Prediction of longevity of merchant ships 828
4.2.1 Prediction of corrosion 829 4.2.2 Fatigue strength prediction 829 4.2.3 Buckling prediction 830
4.3 Prediction of longevity of fixed offshore structures 830 4.4 Conclusions 830
5. PREVENTION & REPAIR OF STRUCTURAL FAILURES 831 5.1 Introduction 831 5.2 Prevention of failure - Design stage 831
5.2.1 Corrosion protection 831 5.2.2 Material selection 832 5.2.3 Structural design 832
5.3 Prevention of failure - Operation 833 5.3.1 Maintenance & inspection 833 5.3.2 Repair and rehabilitation 834
5.4 Conclusions and Recommendations 836
6. INSPECTION METHODS & TECHNIQUES 836 6.1 Introduction 836 6.2 Inspection execution 837 6.3 Inspection techniques 837 6.4 Limitations 838 6.5 Conclusions and Recommendations 839
7. SENSING TECHNOLOGIES 839 7.1 Introduction 839 7.2 Passive systems 840
ISSC committee V.7: STRUCTURAL LONGEVITY 819
7.2.1 Strain 840 7.2.2 Acoustic Emission 840 7.2.3 Vibrations 841 7.2.4 Crack 841 7.2.5 Corrosion 841 7.2.6 Acceleration 841 7.2.7 Metocean information 842
7.3 Active system 842 7.3.1 Impedance-based methods 842 7.3.2 Lamb wave-propagation methods 843
7.4 Data acquisition and processing 844 7.5 Sensor network, wired and wireless 844 7.6 Maturity of Structural Hull Monitoring Systems 844
8. METHODOLOGIES FOR USING INSPECTION & SENSED DATA 845 8.1 Introduction 845 8.2 Operational Advice 846
8.2.1 Identifying loading to stay within safe operating envelope 846 8.2.2 Quantifying operational loading and changes 848
8.3 Lifecycle Management Advice 848 8.3.1 Condition Based Maintenance (CBM) 850 8.3.2 Reliability Centered Maintenance 850 8.3.3 Reliability Based Inspections 850
8.4 Design update based on lessons learned from analysis of failures 851 8.5 Discussion 851 8.6 Conclusions 851
9. LIFE TIME EXTENSION, COMPARISON OUTSIDE & WITHIN THE MARITIME I 852 9.1 Introduction 852 9.2 Lifetime Extension of Existing Structures 852 9.3 Other industries 854 9.4 Differences in approaches for ships, offshore structures, and other
marine structures (ranging from navy to renewable energies) 855 9.5 Conclusions 855
10. CONCLUSIONS & RECOMMENDATIONS 856 10.1 Conclusions 856 10.2 Recommendations 856
REFERENCES 857
NDUSTRY
820 ISSC committee V.7: STRUCTURAL LONGEVITY 1. INTRODUCTION
1.1 Background & Mandate Ships, offshore and other marine platform structures are designed with assumptions regarding construction methods, loading, environment, design criteria, material performance, operation, maintenance, and service life. However, if any design assumption proves incorrect then this could result in a risk and cost to the owner and operator. The actual condition, use, and performance of the platform structure changes over time, which requires updated maintenance requirements for scheduling and budgeting, decisions on limiting or expanding the operational use, and predicting remaining useful service life.
