Research On Fatigue Damage Of Ice-induced Vibration Of Jacket Platform In Service In The Ice-covered Regions

It is indicated that the ice-induced vibration of ice-resistant platforms is quite intensive, and directly endangers the structural safety according to the field data monitored on several platforms in the Liaodong Bay of Bohai Sea. A detailed research and summarization on the ice-induced fatigue of jacket platforms in the ice-covered regions is presented based on in situ results of ice-induced vibration and the current progress of ice load.Firstly, this paper gives an introduction of the current progress of platform fatigue under wave load, ice-covered regions environmental condition, and ice-induced respond of offshore structures, and then presents the assignment. Second, this paper gives an introduction of the basic conception and primary fatigue design methods, and summarizes the run-of-mill fatigue analysis method of platform under wave load, which provides use for reference of fatigue analysis of platform under ice load.Third, The dynamic responds of jacket platforms in the Bohai Sea are analyzed, the vibration acceleration of platform deck is computed and compared with the field monitored data based on the full-scale field tests and progress of ice load, which provides preparative for computing the stress of the tube node of the jacket platform.At last, this paper gives a general analysis and a detailed analysis method of the jacket platform in the ice-covered regions. It points out the necessity of analyzing fatigue life of the platform from qualitative and quantitative sides, based on the dynamic characteristics of jacket platforms. It presents fatigue analysis method based on the field monitored data, and gives a detailed flow of this method. For example, fatigue life of tube node of the JZ20-2MSW jacket platform is computed based on this method.