Journal ArticleDOI
High‐Strength Steels in Welded State for Light‐Weight Constructions under High and Variable Stress Peaks
TLDR
In this paper, the authors evaluated the fatigue performance of high-strength steel structures subjected to complex loading with regard to light-weight design and economics, and determined the real damage sums in order to give recommendations for the fatigue life estimation.Abstract:
In design codes (Eurocode, British Standard and others) for the dimensioning of welded joints, no distinction is made between low-, mediumand high-strength steels. Because of a lack of general knowledge about the benefits of high-strength steels and also because of missing information in design codes, in many cases design engineers still use lowor medium-strength steels (Rp0.2 < 400 MPa) and compensate for high loads under constant or variable amplitude loading or overloads by increasing dimensions. Given this situation, it was deemed necessary to establish criteria for the design of light-weight welded constructions under high and variable stress peaks using new classes of high-strength steels, such as S355N (normalized), S355M (thermomechanically treated), S690Q (water quenched) and S960Q (water quenched), and to perform more reliable evaluations of the fatigue performance of high-strength steel structures subjected to complex loading with regard to light-weight design and economics. For the comparison of the fatigue strengths of the investigated steels the notch factors present were taken into account. Additionally, the real damage sums were determined in order to give recommendations for the fatigue life estimation, i.e. Dal = 0.5. Under constant amplitude loading, no significant difference in the bearable local stress amplitudes for the butt welds can be detected for the four investigated steels. Under variable amplitude loading, the butt welded (lower notch factor) high strength steel S960Q has advantages in the case of the normal Gaussian spectrum and in the case of overloads, especially under pulsating loading. For the transverse stiffeners (high notch factor), slight advantages for the high strength steel S960Q exist, only in the case of pulsating overloads. However, the advantages of high strength steels in case of static loading are indisputable. In most of the investigated cases, overloads lead to a benefit in fatigue life.read more
Citations
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Journal ArticleDOI
Effect of residual stresses on the fatigue behaviour of welded joints depending on loading conditions and weld geometry
TL;DR: In this paper, the structural durability of welded structures is determined by the interaction of different influencing parameters such as loading mode, spectrum shape, residual stresses and weld geometry among others.
Journal ArticleDOI
S-N Lines for Welded Thin Joints — Suggested Slopes and FAT Values for Applying the Notch Stress Concept with Various Reference Radii
TL;DR: In this paper, the S-N line slopes of thin welded structures with actual IIW design lines are derived for the notch stress concept variants with rref = 1.0, 0.3 or 0.05 mm, respectively.
Journal ArticleDOI
Light‐weight design chances using high‐strength steels
TL;DR: In this article, the authors consider the interaction between the service loading, material, geometry and manufacturing technology to make effective use of high-strength steels for designing light-weight structures.
Journal ArticleDOI
Lightweight design with welded high-frequency mechanical impact (HFMI) treated high-strength steel joints from S700 under constant and variable amplitude loadings
TL;DR: In this article, the effect of high-frequency mechanical impact (HFMI) treatment on the fatigue strength of welded joints was investigated under variable amplitude loading with a straight-line spectrum.
Journal ArticleDOI
Application of the weakest link analysis to the area of fatigue design of steel welded joints
TL;DR: In this article, a new approach in the area of fatigue life assessment of steel welded joints is proposed with the following features: (i) methodology of the fatigue life calculation is independent from geometry of the welded element; (ii) fatigue life assess is based on fatigue characteristic of introduced efficient material; and (iii) the assessment is carried on the desired level of failure probability.
References
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Journal ArticleDOI
Course of SN-curves especially in the high-cycle fatigue regime with regard to component design and safety
TL;DR: In this paper, material and manufacturing dependent recommendations are given with regard to the course of the SN-curve in the very high-cycle area, where the authors show that a decrease of fatigue strength with increased number of cycles still occurs, even if corrosion or temperature effects are excluded.
Journal ArticleDOI
Prof. Dr.‐Ing. Erwin Haibach Betriebsfestigkeit Verfahren und Daten zur Bauteilberechnung
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The ASME boiler and pressure vessel code
J.W. Stokes,L. Holly,K.H. Mayer +2 more
TL;DR: The ASME Boiler and Pressure Vessel Code (BPV Code) as discussed by the authors is the most widely used boiler and pressure vessel code in the world and has been adopted as by-laws in most states.
Journal ArticleDOI
Comparison of different methods for presenting variable amplitude loading fatigue results
T. Lagoda,Cetin Morris Sonsino +1 more
TL;DR: In this paper, the authors discuss eight methods for presenting fatigue test results for variable amplitude loading and their comparison with constant amplitude loading, including the maximum amplitude method, most damaging, half damage and mean damage amplitudes.
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