wangwen zhao - Academia.edu (original) (raw)

Papers by wangwen zhao

Journal of Marine Science and Engineering

This paper reassesses the detrimental effect on fatigue performance of welded structural steel jo... more This paper reassesses the detrimental effect on fatigue performance of welded structural steel joints due to thicker sections based on an extensive fatigue strength test database, taken from research programmes worldwide over the past half century, mostly from the offshore oil and gas and marine industries. The data entries in the database were evaluated to ensure its data integrity. Statistical analyses on these S-N data were performed with or without the thickness correction at different exposure levels to a corrosive environment, in order to re-evaluate the suitability of current standards in regard to the thickness effect. The study concentrated on T-joints, transverse butt-welded joints and tubular joints, as these are the most commonly used joint types in the offshore wind industry. The analysis indicates a general agreement of fatigue strength with the thickness effects in current standards for in-air conditions, but great conservatism for corrosive environments. In addition,...

International Journal of Fatigue

This paper reassesses the detrimental effect on fatigue performance due to thicker sections based... more This paper reassesses the detrimental effect on fatigue performance due to thicker sections based on extensive fatigue strength test database, taken from research program worldwide over the past half of a century in offshore oil & gas and renewable industry. The data entries in the database have been evaluated to ensure its data integrity. Statistical analyses on these S-N data are performed with or without the thickness correction at different exposure level to corrosive environment, in order to re-evaluate the suitability of current standards in regard to the thickness effect. The study has concentrated on T-joint, transverse butt welded joint and tubular joint as these are the most commonly used joint types in the offshore wind industry. The analysis indicates general agreement of fatigue strength with the thickness effects in current standard for in air conditions but great conservatism for corrosive environment.

The concept of Design Fatigue Factors (DFFs) was introduced for providing desired level of safety... more The concept of Design Fatigue Factors (DFFs) was introduced for providing desired level of safety in structural fatigue design, often associated with damage calculated from S-N curves. Calculation of fatigue damage from S-N curves can be affected by multiple factors, e.g. types of weld class, corrosion condition, loading conditions, stress concentration on different geometries etc. Each of them can be subject to different level of uncertainties. This study intends to recalibrate the DFFs from a detailed reliability analysis by investigating the probabilistic models derived from the database of S-N curves that has been most frequently used in offshore wind industry. The results of such study indicate that the DFFs can be reduced substantially for the corrosive environmental fatigue models from current standards to the same level of target reliability.

... Wlth the model gven In Eq (13), the normalaed equivalent stress range 1s Page 10. W ZHAO AND ... more ... Wlth the model gven In Eq (13), the normalaed equivalent stress range 1s Page 10. W ZHAO AND M J BAKER and the equivalent stress range 1s ... Page 12. 282 W WAO AND M J BAKER Slnce m = 3 IS the most probable value for structural steel, the relauonship between a and I ...

Volume 3: Materials Technology; Jan Vugts Symposium on Design Methodology of Offshore Structures; Jo Pinkster Symposium on Second Order Wave Drift Forces on Floating Structures; Johan Wichers Symposium on Mooring of Floating Structures in Waves, 2011

Volume 5: Materials Technology; CFD and VIV, 2008

International Journal of Fatigue, 1992

... 30) Finally, to summarize, for a stress process modelled as a stationary Gaussian process, if... more ... 30) Finally, to summarize, for a stress process modelled as a stationary Gaussian process, if only ... 7 Linear regression of data points from simulation results in Table 1 s is obtained ... Example For a given stress spectrum, the normal procedure for determining the stress range PDF ...

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 3, 2002

Journal of Marine Science and Engineering

This paper reassesses the detrimental effect on fatigue performance of welded structural steel jo... more This paper reassesses the detrimental effect on fatigue performance of welded structural steel joints due to thicker sections based on an extensive fatigue strength test database, taken from research programmes worldwide over the past half century, mostly from the offshore oil and gas and marine industries. The data entries in the database were evaluated to ensure its data integrity. Statistical analyses on these S-N data were performed with or without the thickness correction at different exposure levels to a corrosive environment, in order to re-evaluate the suitability of current standards in regard to the thickness effect. The study concentrated on T-joints, transverse butt-welded joints and tubular joints, as these are the most commonly used joint types in the offshore wind industry. The analysis indicates a general agreement of fatigue strength with the thickness effects in current standards for in-air conditions, but great conservatism for corrosive environments. In addition,...

International Journal of Fatigue

This paper reassesses the detrimental effect on fatigue performance due to thicker sections based... more This paper reassesses the detrimental effect on fatigue performance due to thicker sections based on extensive fatigue strength test database, taken from research program worldwide over the past half of a century in offshore oil & gas and renewable industry. The data entries in the database have been evaluated to ensure its data integrity. Statistical analyses on these S-N data are performed with or without the thickness correction at different exposure level to corrosive environment, in order to re-evaluate the suitability of current standards in regard to the thickness effect. The study has concentrated on T-joint, transverse butt welded joint and tubular joint as these are the most commonly used joint types in the offshore wind industry. The analysis indicates general agreement of fatigue strength with the thickness effects in current standard for in air conditions but great conservatism for corrosive environment.

The concept of Design Fatigue Factors (DFFs) was introduced for providing desired level of safety... more The concept of Design Fatigue Factors (DFFs) was introduced for providing desired level of safety in structural fatigue design, often associated with damage calculated from S-N curves. Calculation of fatigue damage from S-N curves can be affected by multiple factors, e.g. types of weld class, corrosion condition, loading conditions, stress concentration on different geometries etc. Each of them can be subject to different level of uncertainties. This study intends to recalibrate the DFFs from a detailed reliability analysis by investigating the probabilistic models derived from the database of S-N curves that has been most frequently used in offshore wind industry. The results of such study indicate that the DFFs can be reduced substantially for the corrosive environmental fatigue models from current standards to the same level of target reliability.

... Wlth the model gven In Eq (13), the normalaed equivalent stress range 1s Page 10. W ZHAO AND ... more ... Wlth the model gven In Eq (13), the normalaed equivalent stress range 1s Page 10. W ZHAO AND M J BAKER and the equivalent stress range 1s ... Page 12. 282 W WAO AND M J BAKER Slnce m = 3 IS the most probable value for structural steel, the relauonship between a and I ...

Volume 3: Materials Technology; Jan Vugts Symposium on Design Methodology of Offshore Structures; Jo Pinkster Symposium on Second Order Wave Drift Forces on Floating Structures; Johan Wichers Symposium on Mooring of Floating Structures in Waves, 2011

Volume 5: Materials Technology; CFD and VIV, 2008

International Journal of Fatigue, 1992

... 30) Finally, to summarize, for a stress process modelled as a stationary Gaussian process, if... more ... 30) Finally, to summarize, for a stress process modelled as a stationary Gaussian process, if only ... 7 Linear regression of data points from simulation results in Table 1 s is obtained ... Example For a given stress spectrum, the normal procedure for determining the stress range PDF ...

21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 3, 2002