An Assessment Method For Structure Strength Of Icebreaker In Service

Due to the higher latitudes,There is ice period in China's Huanghai-Sea and Bohai-Sea region in winter.During this period,the icebreaker is responsible for opening waterway for the ships navigating in this area and delivering supplies for people living on the offshore platforms or the nearby islands.There is only few icebreaker in service in China,and most of them have been extended service.The corrosion of structure and the reduction of power system is very obvious for these icebreaker.Because of these changes,the structural strength and icebreaking way of these aging icebreakers will be affected.Eventually,the structure safety when icebreakers are in operation will be affected.There are two methods,which are based on rules and numerical simulation respectively,are used in strength assessment for icebreakers.In this paper,the effect of the structure corrosion and the change of icebreaking way are considered.Then,the strength assessment method for the aging icebreaker is investigated.The main work is as follows,(1)The different corrosion models are studied.Through the comparison of the calculation accuracy and application scope,the numerical corrosion model which is fit for the aging icebreaker is determined.The corrosion value of an icebreaker in service is predicted with the it.(2)The I ACS rule for navigating in ice is studied.The way how to calculate ice load and add to the structure model and the principle how to create the structure model are investigated.Based on these research,the structure strength assessment of the icebreaker in service is carried out.(3)The icebreaking process is simulated by the dynamic simulation method.The ice load and the dynamic response is obtained by using nonlinear finite element method.Then the key part strength of an icebreaker in service is analyzed.