A method for modifying octagonal Goodman–Smith fatigue limit diagram

Abstract

PurposeIn order to extend the application of the original octagonal Goodman–Smith fatigue limit diagram, which is commonly used for the evaluation of structure fatigue stress in engineering, a modification of it is proposed for the structure made of S355 steel (commonly used in high-speed electric multiple units (EMUs) bogie frame).Design/methodology/approachThe modification is made based on Deutscher Verband für Schweißen und verwandte Verfahren e. V. (DVS) 1612 standard and the γ-P-S-N curve, with consideration of the fatigue evaluation requirements of different survival rates and confidence levels. The verification of the modification is performed for three welded joints and for the comparison with the experimental data.FindingsThe results indicate that the design survival rate, the design safety margin and the fatigue stress evaluation of welded joint types are all improved by using the modified diagram.Originality/valueThere are relatively few studies on modifying octagonal Goodman–Smith fatigue limit diagram. In this paper, a modified diagram is proposed and applied in order to ensure the safety and durability of key welded structures of rail vehicles.

Editorial: Second issue 2024 and IJSI journal awards

“…Tang et al . (2024) presented an extension of the application of the original Goodman-Smith octagonal fatigue limit diagram, which is commonly used for the assessment of structure fatigue stress in engineering.…”

“…Khajuria et al (2024) developed a study on the influence of CMT-MAG and MAG weldingprocesses on microstructure and mechanical behaviour of C-Mn E410 structural-steels, where a substantial improvement in YS (∼9%), %elongation (∼38%) and room temperature impact toughness (∼29%) of 0.04wt.%C E410 steel is achieved with CMT-MAG over MAG welding, and almost ∼10, ∼12.5 and ∼16% increment in YS, %elongation and toughness of 0.17wt.%C E410 steel is observed with CMT-MAG. Tang et al (2024) presented an extension of the application of the original Goodman-Smith octagonal fatigue limit diagram, which is commonly used for the assessment of structure fatigue stress in engineering. Based on this study, the authors applied the modified diagram in order to ensure the safety and durability of the main welded structures of railway vehicles.…”