For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design conditions are calculated by use of the three-dimensional boundary element method. Methods for calculatin...For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design conditions are calculated by use of the three-dimensional boundary element method. Methods for calculating the forward-speed free-surface Green function are discussed and a computer program with this Green function is developed. According to the special rules, the wave loads under several typical design conditions of the platform are calculated. The maximum vertical bending moment, torsion moment and horizontal split force are determined from a series of contour maps of wave loads for the wave period of 5 to 18 seconds at a certain interval and the wave phase of 0degrees to 360degrees at a certain interval. The wave height is determined by the function of wave period with a given exceedance probability. The maximum wave loads under the combination of wave parameters are used as the input of hydrodynamic pressure in the three-dimensional finite element analysis process. The transfer functions of wave loads on the platform are used for the fatigue strength analysis of the K-tubular joint and the sub-model of the structure.展开更多
Records of wave-induced damage on coastal bridges during natural hazards have been well documented over the past two decades.It is of utmost importance to decipher the loading mechanism and enhance the resilience of c...Records of wave-induced damage on coastal bridges during natural hazards have been well documented over the past two decades.It is of utmost importance to decipher the loading mechanism and enhance the resilience of coastal bridges during extreme wave-inducing events.Quantification of vulnerability of these structures is an essential step in designing a resilient bridge system.Recently,considerable efforts have been made to study the force applied and the response of coastal bridge systems during extreme wave loading conditions.Although remarkable progress can be found in the quantification of load and response of coastal superstructures,very few studies assessed coastal bridge resiliency against extreme wave-induced loads.This paper adopts a simplified and practical technique to analyze and assess the resilience of coastal bridges exposed to extreme waves.Component-level and system-level fragility analyses form the basis of the resiliency analysis where the recovery functions are adopted based on the damage levels.It is shown that wave period has the highest contribution to the variation of bridge resiliency.Moreover,this study presents the uncertainty quantification in resiliency variation due to changes in wave load intensity.Results show that the bridge resiliency becomes more uncertain as the intensity of wave parameters increases.Finally,possible restoration strategies based on the desired resilience level and the attitude of decision-makers are also discussed.展开更多
文摘For the global and structural fatigue strength analysis of a semi-submersible platform, wave loads under design conditions are calculated by use of the three-dimensional boundary element method. Methods for calculating the forward-speed free-surface Green function are discussed and a computer program with this Green function is developed. According to the special rules, the wave loads under several typical design conditions of the platform are calculated. The maximum vertical bending moment, torsion moment and horizontal split force are determined from a series of contour maps of wave loads for the wave period of 5 to 18 seconds at a certain interval and the wave phase of 0degrees to 360degrees at a certain interval. The wave height is determined by the function of wave period with a given exceedance probability. The maximum wave loads under the combination of wave parameters are used as the input of hydrodynamic pressure in the three-dimensional finite element analysis process. The transfer functions of wave loads on the platform are used for the fatigue strength analysis of the K-tubular joint and the sub-model of the structure.
基金sponsored by the Natural Science and Engineering Research Council(NSERC)of Canada through the Discovery Grant and additional funding provided by University of Calgary through the start-up grant.
文摘Records of wave-induced damage on coastal bridges during natural hazards have been well documented over the past two decades.It is of utmost importance to decipher the loading mechanism and enhance the resilience of coastal bridges during extreme wave-inducing events.Quantification of vulnerability of these structures is an essential step in designing a resilient bridge system.Recently,considerable efforts have been made to study the force applied and the response of coastal bridge systems during extreme wave loading conditions.Although remarkable progress can be found in the quantification of load and response of coastal superstructures,very few studies assessed coastal bridge resiliency against extreme wave-induced loads.This paper adopts a simplified and practical technique to analyze and assess the resilience of coastal bridges exposed to extreme waves.Component-level and system-level fragility analyses form the basis of the resiliency analysis where the recovery functions are adopted based on the damage levels.It is shown that wave period has the highest contribution to the variation of bridge resiliency.Moreover,this study presents the uncertainty quantification in resiliency variation due to changes in wave load intensity.Results show that the bridge resiliency becomes more uncertain as the intensity of wave parameters increases.Finally,possible restoration strategies based on the desired resilience level and the attitude of decision-makers are also discussed.
