Background and activities
Areas of activity
Mechanical Integrity and Fatigue Design
Recent and current research activities
FeVIND: Fatigue assessment (methods and data) of ductile cast iron components for wind turbines
- Weakest-link modelling, size effect
- Determination of size distribution of casting defects by means of X-ray computed tomography
- Monte-Carlo simulation of fatigue-crack growth from randomly distributed casting defects
MATSINT: Fatigue assessment of notches and cracks in ductile cast iron
- Self-arresting cracks at notches
- Fatigue assessment of notched components
- Growth of (short) fatigue cracks
Advanced Fatigue Modelling in Design
- Statistical description of defects
- Probabilistic modelling of fatigue limit
- Multiaxial fatigue assessment criteria
- Probabilistic fatigue assessment of Francis turbine runners
Current teaching activities
- TMM4195 Fatigue Design
Education and Experience
- Professor of Solid Mechanics at NTH (Trondheim)
- Visiting Professor at KTH (Stockholm), ETH (Zürich), University of Oxford and Visiting Fellow of Lincoln College (Oxford)
Research work on
- Non-metallic inclusions and fatigue
- Prestressed (wire-wound) high-pressure vessels
- Fatigue and creep at notches
- High-temperature fatigue
- Creep design
- Thermal stress
- Fretting fatigue
- Gas-turbine blades and disks
- Growth of short fatigue cracks
- Fatigue cracks at notches and defects incl. self-arresting cracks
- Weakest-link fatigue analysis
- Fatigue assessment of (heavy) components of ductile cast iron
- FEA post-processor for fatigue assessment
- Multiaxial fatigue
- Fatigue assessment of Francis turbine runners
- NTNU course in Machine Elements during ten years; Author of textbook (Tapir, 2004, edited reprint 2012) Dimensjonering av maskindeler
- Twenty years of experience from Swedish and Swiss industry with responsibility for advanced stress and lifetime analyses, materials development and materials selection for gas and steam turbines and high-pressure equipment.
- MSc (Engineering Physics) and DSc (Solid Mechanics) from KTH (Stockholm)
Membership in Academic and Professional Committees and Societies, Awards
- Member of the Swedish Fatigue Network, UTMIS (SE), member of the board 2007-2010
- Member of the European Structural Integrity Society, ESIS
- Fellow of the Institution of Mechanical Engineers, IMechE (UK), since 2008
- Member of the Editorial Board of the Journal of Strain Analysis (UK) 1998-2007
- CEGB Prize 2004
- Life Member of the American Society of Mechanical Engineers, ASME (US)
Search under 'Research results/NVI, Surname: Härkegård or H*rkeg*rd, First name: Gunnar
Scientific, academic and artistic work
A selection of recent journal publications, artistic productions, books, including book and report excerpts. See all publications in the database
- (2017) Finite element analysis of peak stress and stress gradient at an elliptical through-hole. Journal of Strain Analysis for Engineering Design. vol. 52 (5).
- (2017) A simplified method for weakest-link fatigue assessment based on finite element analysis. International Journal of Fatigue. vol. 100 (1).
- (2016) Modelling the effect of a spherical cavity on the fatigue limit of a 12% Cr steel. Theoretical and applied fracture mechanics (Print). vol. 84.
- (2015) A comparative study of design code criteria for prediction of the fatigue limit under in-phase and out-of-phase tension-torsion cycles. International Journal of Fatigue. vol. 73.
- (2015) Short-crack modelling of the effect of corrosion pits on the fatigue limit of 12% Cr steel. Fatigue & Fracture of Engineering Materials & Structures (FFEMS). vol. 38 (9).
- (2014) Experimental and modeling study of the effect of corrosion pitting on fatigue failure locations in aircraft components. Advanced Materials Research. vol. 891-892.
- (2014) A novel probabilistic fatigue assessment tool and its application to an offshore riser joint. Procedia Materials Science. vol. 3.
- (2013) The fatigue limit: An analytical solution to a Monte Carlo problem. International Journal of Fatigue. vol. 55.
- (2013) A physically based extreme value characterization of material fatigue. International Journal of Fatigue. vol. 47.
- (2013) Round-robin prediction of the fatigue limit of a ring of spheroidal graphite cast iron. Fatigue & Fracture of Engineering Materials & Structures (FFEMS). vol. 36 (5).
- (2013) Self-arresting cracks at notches in ductile cast iron. Engineering Fracture Mechanics. vol. 102.
- (2012) On the effect of random defects on the fatigue notch factor at different stress ratios. International Journal of Fatigue. vol. 41.
- (2012) Damage tolerant design of cast components based on defects detected by 3D X-ray computed tomography. International Journal of Fatigue. vol. 41.
- (2012) Fracture toughness and growth of short and long fatigue cracks in ductile cast iron EN-GJS-400-18-LT. Fatigue & Fracture of Engineering Materials & Structures (FFEMS). vol. 35 (4).
- (2011) Casting defects and fatigue behaviour of ductile cast iron for wind turbine components: A comprehensive study. Materialwissenschaft und Werkstofftechnik. vol. 42 (12).
- (2011) Fatigue life distribution and size effect in ductile cast iron for wind turbine components. Engineering Failure Analysis. vol. 18 (1).
- (2011) Large scale axial fatigue testing of ductile cast iron for heavy section wind turbine components. Engineering Failure Analysis. vol. 18 (6).
- (2010) Fatigue life prediction for large threaded components. Procedia Engineering. vol. 2 (1).
- (2010) Assessment of methods for prediction of notch and size effects at the fatigue limit based on test data by Bohm and Magin. International Journal of Fatigue. vol. 32 (10).
- (2010) Fatigue Life Prediction of Components Made of Spheroidal Graphite Cast Iron. Procedia Engineering. vol. 2 (1).