摘要
破损船体破口处存在应力集中,等值梁法不能解决破口应力集中问题。用有限元法研究了船底加筋板格破口的应力分布规律,分析了在矩形、尖角矩形、圆形三种典型破口下的应力集中系数,将破口的应力集中系数分解为平板应力集中系数和骨材作用系数,根据它们的递变规律,提出应力集中系数的一种简化的算法;考虑破口的初始应变和破口进入非弹性阶段后材料的非线性,对破口弹性应力集中系数进行修正并拟合了修正公式;最后提出了采用等值梁法求船底基准应力,结合破口的应力集中系数和破口应力分布规律来计算破损船体总纵强度的方法,对等值梁法的计算结果进行修正,使破损船体强度校核更加真实可靠。算例表明该方法简单可行且具有较好的精度。
The break of the damaged ship has a problem of stress concentration and the simple beam method can＇t solve it. It is analyzed the stress distribution of break at bottom stiffened plate frame by FEA. Breaks ＇ SCF in three typical shapes of square, sharp corners rectangular and circle is analyzed. SCF is divided into flat and the aggregate effect of stress concentration factor. According to their graded rules, it is proposed a simplified algorithm. Considering the initial strain and material nonlinearity of breaks at the inelastic stage, it is to modify the elastic stress concentration factor on the break and fitting a modified formula. Finally, a method is proposed to use the simple beam theory to calculate the nominal stress combined with the distribution of SCF and stress of break, to calculate longitudinal strength of damaged ships. Modifying the results of simple beam makes the check for damaged hull strength more reliable. Examples show that the proposed method is simple and feasible and has good accuracy.
出处
《船舶工程》
CSCD
北大核心
2012年第1期6-11,共6页
Ship Engineering
