船舶工程英语(船舶危险状态下的纵向强度计算).doc

Longitudinal strength of ships with accidental damages 船舶危险状态下的纵向强度计算 Abstract 摘要 This paper presents an investigation of the longitudinal strength of ships with damages due to grounding or collision accidents. 此文将提到关于船舶在搁浅和碰撞两种危险状况下的调查报告。Analytical equations are derived for the residual hull girder strength and verified with direct calculations of sample commercial ships for a broad spectrum of accidents. 给出了破损船体计算方程式和典型商船事故的直接计算方法。Hull girder ultimate strengths of these sample vessels under sagging and hogging conditions are also calculated, based on which correlation equations are proposed. 船体梁在中垂和中拱下根据所给出的方程式计算极限强度。To evaluate a grounded ship, using the section modulus to the deck would be optimistic, while using the section modulus to the bottom would be conservative. 为了评估搁浅的船，计算时甲板的剖面模数要取得大些，而船底剖面模数要取得小些。 On the contrary, to evaluate a collided ship, using the section modulus to the deck would be conservative, while using the section modulus to the bottom would be optimistic. 相反的，在估算碰撞条件下船时甲板的剖面模数要取得小些，而船底剖面模数要取得大些。The derived analytical formulae are then applied to a fleet of 67 commercial ships, including 21 double hull tankers, 18 bulk carriers, 22 single hull tankers and six container carriers. 导出的方程适用于67系列商船，21型双壳油船，18型散货船，22型单壳油船和6型集装型船。The mean values, standard deviations and coefficients of variation for the coefficients in these new analytical formulae are obtained. 其主要数值、标准差、变动系数将从这些新的分析方程中获得。The ship length exhibits little influence on these coefficients because they are close to the mean values although ship length spans from 150 to 400 m. The ship type shows some influence on the residual strength. 船长对这些数值的影响是很小的，即使船长从150m长到400m。而船的类型不同将有对船的剩余强度有影响。Uniform equations are proposed for commercial ships which do not depend on a ship’s principal dimensions. These formulae provide very handy tools for predicting the residual strength in seconds, without performing step-by-step detailed calculations, an obvious advantage in cases of emergency or salv