The plating in ships is generally subjected to combined in - plane and lateral pressure loads . in - plane loads include biaxial compression / tension and in - plane bending and edge shear , which are mainly induced by overall hull girder bending and / or torsion of the vessel . lateral pressure loads are due to water pressure and cargo 面内载荷分为轴向压应力或拉应力、边缘剪切应力以及面内轴向弯曲应力。实际的船舶结构中面内载荷通常由船体梁的总纵弯曲或者船体梁的扭转引起。侧向压应力则由水压力和货物压力引起。
A time - variant reliability formulation is presented in this paper to account for the effects of fatigue , corrosion and maintenance actions on the first yield reliability of midship section modulus . a probabilistic model for long - term distribution of wave - induced fatigue stress range is established . for the purpose of obtaining the performance of structure that stands random fatigue load , the concept of stress parameter and equivalent stress range are introduced 船舶在由波浪弯矩引起的交变应力作用下，船体构件焊接点处的微小裂纹逐渐扩展；同时，随着船龄的增加，众多结构构件遭受腐蚀的作用；从而使船体梁剖面模数减小，船体梁承载能力衰减，船舶结构的安全性将受到相当大的影响。
Whereas ship structural design is most important in the process of ship design . using proper optimization technique and programming languages acquiring requisite design plotter program is very significant research and exploration based on autocad2000 platform . moreover , it is very miscellaneous and meticulous design 而船舶结构设计又是船舶设计中极其重要的一环，在整个船舶设计过程中有着十分重要的地位，选用适当的优化技术结合编程语言，在常用的软件autocad2000的平台上，得到满足设计需要的设计绘图程序，以此进行船舶结构设计，是一项非常有意义的研究和探索。
