系泊船舶在横浪作用下撞击能量计算参数C_m取值研究

船舶附加水体质量系数C_m的取值对计算系泊船舶在横浪作用下的撞击能量具有十分重要的影响,目前国内外相关文献对该参数取值差异较大,且国内水运行业规范的参数取值偏小,给结构安全带来一定隐患。经过对取值规定的比较,并参照计算公式、结合工程实例分析计算结果,得知国内现行规范C_m的取值明显小于国内外相关规范和研究报告的取值。建议20万吨级以上船舶增大C_m取值为1.7~2.0。

Value of calculation coefficient of mooring ship with impact energy in beam sea

The value of Cm, the coefficient of hydrodynamic mass, has an important influence on the calculation of the impact energy of mooring ship in the beam sea. At present, there is a great difference among the values of Cm in current relative domestic and oversea documents, and the coefficient value in domestic water transportation industry standards is smaller, which is a hidden danger of building structures. Compared with the regulations on this value, and analyzing the results by referring to formulae and combining the engineering project, we know that the value of Cm in domestic current standards is obviously less than that appeared in other domestic and foreign codes and research reports. It is suggested that Cm for ships larger than 200 000 DWT should be increased to the value between 1.7 and 2.0.