Dr. Jens P. Tronskar M.Sc., PhD, CEng, SenMWeldI, IWE, FSWS is a certified International Welding Engineer (IWE), a senior member of The Welding Institute and a UK‐Engineering Council Charted Engineer (C.Eng.) and elected Fellow of Singapore Welding Society (FSWS). Presently he holds a position as Senior Vice President and Chief Technology Officer at DNV GL’s Oil & Gas Technology Centre in Singapore. He has more than 35 years of experience of materials technology research, failure investigations, root cause analyses, risk based inspection and deterministic/ probabilistic fracture mechanics analyses/ Fitness‐For‐Service analyses of pipelines, structures, piping/process equipment for the offshore and onshore oil & gas industry. The experience includes deterministic and probabilistic fracture mechanics and Fitness‐For‐Purpose and Engineering Critical Assessment of welds in C‐Mn, CRA and CRA clad materials. The environmental and loading conditions have included sour service, vortex induced vibration (VIV), lateral buckling and large strain associated with pipeline reeling and lateral buckling. Dr. Tronskar has been involved in materials evaluation and testing for many North Sea field development projects since the early 80s. He has been based in Asia since 1994 and has been involved in similar work for offshore and onshore projects in South East Asia, China, South Korea, Russia, Australia and Middle East and Africa. Dr. Tronskar has been project sponsor and manager for a large number of pipeline ECAs and FFS projects. Dr. Tronskar has presented papers at international conferences in Europe, America, South America, Australia and Asia. He has published more than 70 journal articles and peer reviewed conference papers on materials technology, welding and deterministic and probabilistic fracture mechanics analyses.
Codes for design and construction of pressure vessels, pipelines, offshore structures, bridges and buildings, process plants etc. normally contain acceptance criteria that are based on workmanship standards that may be somewhat arbitrary. During the construction phase or in service, there may be situations where materials properties or observed defects do not meet the strict code requirements. In such cases a Fitness‐For‐Service assessment can be applied. Such an approach is nowadays becoming accepted by many codes as it is recognized that the requirements or acceptance criteria inherent in the codes may be unnecessarily conservative. Using this alternative approach it can be shown that the structure or component can be acceptable if the conditions for failure are not reached within its service life. There are many possible damage or degradation mechanisms which must be considered. These include brittle and ductile fracture, fatigue, environmental assisted cracking and creep at higher temperatures.
There are now several publications and recommended practices available that describe the Fitness‐For‐Service and ECA approaches.
- British Standard, BS 7910: 2005/2013 "Guide on the methods for assessing the acceptability of flaws in metallic structures".
- API 579‐1/ ASME FFS‐1 “Fitness‐For‐Service” June, 2016.
- DNV GL Recommended Practice F‐101 “Corroded Pipe”, 2015.
- DNV GL Recommended Practice F‐108 “Fracture Control for Pipeline Installation Methods Introducing Cyclic Plastic Strain”, 2006.
- DNV GL Offshore standard (OS) F‐101 “Submarine Pipeline Systems”. 2010 and 2013 versions.
- ASME B31.8 and 31.8S.
DNV GL has developed a course programme focusing on the practical application of Fitness‐For‐Service and ECA particularly for pipelines and structures. The course also covers a brief introduction of finite element analysis (FEA) to determine the stress and strain input to the analysis and covers advanced flaw modelling and J‐integral analysis to derive the crack driving force and limit loads. It is intended that the participants attending this course shall become confident in performing Option 1 and Option 2 analyses according to BS 7910: 2013 and that they also will be introduced to option 3 where the FAD is derived through FEA and including ductile tearing assessments.
The course will cover the theoretical background for elastic and elastic plastic fracture mechanics and the fracture assessment diagram (FAD) methods, fatigue crack growth and tearing analysis. Further the course will also give insight into the practical aspects of elastic‐ plastic fracture toughness (CTOD, J) testing of weldments and the requirements to non‐destructive testing for flaw sizing and development of alternative flaw acceptance criteria for pipeline installation. The first three days (Days 1‐3) of the course also covers applications involving high strain due to lateral buckling, reeling installation and high temperatures in clad pipelines and effect of fatigue loading due to vortex induced vibration (VIV) associated with free spans. The fourth day (Day 4) of the course which is optional covers an introduction of finite element modelling, definition of boundary conditions and material models and finite element based fracture mechanics analysis to generate stress/strain input to general design and ECA/FFS assessments.
Who should attend?
The course is aimed at welding and inspection, structural, mechanical, construction, design and maintenance engineers requiring more knowledge of the application of fitness‐for‐purpose assessment methods for structures, piping/ pipelines and pressure vessels.
We can also conduct a customized in-house training course and bring it to your place at your convenient time.