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。
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.
2021,43(4): 18-22 收稿日期：2020-05-10
DOI：10.3404/j.issn.1672-7649.2021.04.004
分类号：U674
作者简介：常桐(1993-),男,助理工程师,主要从事舰船设计与制造
参考文献：
[1] CCS. 散货运输液化气体船舶构造与设备规范.[M]. 2018.
[2] DNVGL. Liquefied gas carriers with independent prismatic tanks of type A and B[S]. October, 2015.
[3] BS7910, Guide on methods for assessing the acceptability of flaws in metallic structures[M]. British Standard Institution, 2005.
[4] American Bureau of Shipping. Guide for building and classing of liquefied gas carriers with independent tanks[S]. June, 2017.
[5] GERY W. Leak-Before-Break: What Does It Really Mean?[J]. Journal of Pressure Vessel Technology, 2000, 122: 267−272.
