Additional, in "MARPOL Reg 12a" the demand of DoubleHull Protection for fuel oil tank, increases the difficulty of structure design for engine room.
加之MARPOL 12 A条款要求对燃油舱设置双壳保护，给机舱的结构设计增加了难度。
2
Fourthly, by analyzing the transition structure models of cylindrical hull, the double arcs transition model is put forward, and the calculation results indicate that the new transition model is well.
分析潜艇耐压船体过渡段结构型式，提出了双圆弧式过渡段，并对其结构强度进行计算研究。
3
Based on the optimization modal in ANSYS, the structural design for the portal framed structure of a double-hull sand dredge was optimized.