A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Fatigue strength assessment of ultra-high-strength steel fillet weld joints using 4R method
Abstract A fatigue analysis on experimentally tested transverse fillet-welded non-load-carrying T- and X-joints made of S960 and S1100 ultra-high-strength steel was carried out in the present study. The test data consisted of welded joints in the as-welded, high frequency mechanical impact-treated, and tungsten inert gas-dressed conditions, that were fatigue tested using uniaxial constant amplitude loading with an applied stress ratio of R = 0.1–0.5. The weld geometry and residual stress measurements were carried out, and for each joint, the fatigue strength was assessed using a multiparametric notch stress approach, entitled the 4R method, which incorporates the consideration of four parameters, i.e. notch stress range Δσ k(r), applied stress ratio R, material ultimate strength R m, and residual stress σ res in the fatigue assessment. In the 4R method, the local cyclic elastic-plastic behavior at the notch root is obtained, and the Smith-Watson-Topper parameter is applied to conduct a mean stress correction to commeasure all results into a single S-N curve. The results showed that the applied stress ratio had a distinct influence on the fatigue strength capacity for both joints in the as-welded and post-weld treated conditions when using the conventional stress-based approaches, i.e. nominal stress, structural hot-spot stress and effective notch stress concepts. Nevertheless, the 4R method resulted in a good agreement between the experimental test results and the fatigue strength assessments, regardless of the load and joint conditions.
Highlights Fatigue analysis of experimentally tested ultra-high-strength steel joints. Fillet weld joints in as-welded and post-weld treated condition. Effect of external stress ratio on fatigue strength capacity is evaluated. Mean stress correction on fatigue strength is conducted using 4R method.
Fatigue strength assessment of ultra-high-strength steel fillet weld joints using 4R method
Abstract A fatigue analysis on experimentally tested transverse fillet-welded non-load-carrying T- and X-joints made of S960 and S1100 ultra-high-strength steel was carried out in the present study. The test data consisted of welded joints in the as-welded, high frequency mechanical impact-treated, and tungsten inert gas-dressed conditions, that were fatigue tested using uniaxial constant amplitude loading with an applied stress ratio of R = 0.1–0.5. The weld geometry and residual stress measurements were carried out, and for each joint, the fatigue strength was assessed using a multiparametric notch stress approach, entitled the 4R method, which incorporates the consideration of four parameters, i.e. notch stress range Δσ k(r), applied stress ratio R, material ultimate strength R m, and residual stress σ res in the fatigue assessment. In the 4R method, the local cyclic elastic-plastic behavior at the notch root is obtained, and the Smith-Watson-Topper parameter is applied to conduct a mean stress correction to commeasure all results into a single S-N curve. The results showed that the applied stress ratio had a distinct influence on the fatigue strength capacity for both joints in the as-welded and post-weld treated conditions when using the conventional stress-based approaches, i.e. nominal stress, structural hot-spot stress and effective notch stress concepts. Nevertheless, the 4R method resulted in a good agreement between the experimental test results and the fatigue strength assessments, regardless of the load and joint conditions.
Highlights Fatigue analysis of experimentally tested ultra-high-strength steel joints. Fillet weld joints in as-welded and post-weld treated condition. Effect of external stress ratio on fatigue strength capacity is evaluated. Mean stress correction on fatigue strength is conducted using 4R method.
Fatigue strength assessment of ultra-high-strength steel fillet weld joints using 4R method
Ahola, A. (author) / Skriko, T. (author) / Björk, T. (author)
2019-11-06
Article (Journal)
Electronic Resource
English
Fatigue strength of TIG-dressed ultra-high-strength steel fillet weld joints at high stress ratio
| British Library Online Contents | 2017
Effect of weld toe geometry on fatigue life of lap fillet welded ultra-high strength steel joints
| British Library Online Contents | 2018
Effect of weld toe geometry on fatigue life of lap fillet welded ultra-high strength steel joints
| British Library Online Contents | 2018