液化气体船独立液舱的疲劳与断裂寿命预测

随着低温、高强度钢和薄板在液化气体船上的广泛应用,使得液舱结构安全性问题愈发严重,传统的强度评估方法已经不能满足产品设计的特殊要求,基于断裂力学的疲劳寿命评估已成为液化气体船结构安全评估的主要手段。本文选取江南造船自主研发的超大型乙烷运输船为研究对象,其独立液舱的舱体采用低温镍钢5Ni材料,可运载温度低至-104℃的乙烯、乙烷和丙烷等货品,需满足IGC CODE,USCG和船级社规范等要求。本文采用BS7910失效评定方法和Pairs裂纹扩展速率计算公式,完成液舱结构初始表面裂纹扩展至贯穿型裂纹,再产生结构断裂失效损坏的寿命预测,为超大型乙烷运输船的自主研发提供一种有效的技术途径。

Fatigue and fracture life prediction of liquefied gas carrier's independent tank

With the wide application of the low-temperature,high-strength and thin plate steel in the liquefied gas carrier,the safety problem of cargo tank structure becomes more and more serious,the traditional strength evaluation method already cannot meet the special requirements of product design,fatigue and fracture mechanics assessment has become a major structural safety evaluation method.In this paper,the very large ethane carrier independently developed by JiangNan shipyard is selected as the research object,low-temperature nickel steel 5Ni is applied to the independent cargo tank,which can carry ethylene,ethane,propane and other goods with the temperature as low as-104℃,The tank design should meet the requirements of IGC CODE and classification society rule.BS7910 failure evaluation method and Pairs crack growth rate formula are adopted to predict the lifetime of initial surface crack growth to through-thickness crack of tank structure,and then to generate structural fracture failure damage.This paper provides an effective technical solution for the independent research of the very large ethane carrier.