The precision controlling technology is a key step for the modern ship construction, with the precision controlling of the ship-hull curvature as one of bottlenecks in shipbuilding, where the initial is to present a c...The precision controlling technology is a key step for the modern ship construction, with the precision controlling of the ship-hull curvature as one of bottlenecks in shipbuilding, where the initial is to present a compensation value for the ship-hull plate precisely. The compensation value of the curvature plate is composed of two parts: the construction compensation, which results in the process of heating construction of curvature plate, and the assembling compensation, which results in welding ribbed stiffeners onto the curvature plate. Based on the developed computation system for the local contraction value, this paper presents a method to establish the experimented samples for the assembling compensation by means of numerical experiments, and another method to establish the practical mathematical model for the construction compensation of curvature plate. Furthermore, it introduces the experimental measuring method for the assembling compensation of the curvature plate, based on which the related database system has been developed. Numerical examples are analyzed to demonstrate the process to establish mathematical model for the assembling compensation values.展开更多
为适应新形势下的海上油田开发需求,以“海洋石油122”圆筒形浮式生产储卸油系统(Floating Production Storage and Offloading System,FPSO)为例,从坞内布置分析、船体分段划分方案、船体分段预制与合龙和船体管线与关键设备的安装等...为适应新形势下的海上油田开发需求,以“海洋石油122”圆筒形浮式生产储卸油系统(Floating Production Storage and Offloading System,FPSO)为例,从坞内布置分析、船体分段划分方案、船体分段预制与合龙和船体管线与关键设备的安装等方面对船体建造工艺进行论述。该工艺采用全过程精度控制管理方式,确保关键设备安装精度,减少总装阶段的密闭空间作业量,大幅压缩项目工期,可为后续同类项目的开展提供技术参考。展开更多
为简化围度尺寸计算过程,首先将三维人体截面点云转化到平面坐标系内,然后采用快速比较法获取点集中的4个极值点,并根据极值点将点集分成4个子区域,根据每个子区域点集的凸包具有单调性这种特性,对区域内点集的x和z坐标值进行排序比较...为简化围度尺寸计算过程,首先将三维人体截面点云转化到平面坐标系内,然后采用快速比较法获取点集中的4个极值点,并根据极值点将点集分成4个子区域,根据每个子区域点集的凸包具有单调性这种特性,对区域内点集的x和z坐标值进行排序比较去掉部分凹点,再通过计算点与相邻2点组成向量的叉积判断其夹角范围获取截面凸包点,将最终凸包点连接起来即为人体围度尺寸。结果表明:本文方法与 Graham 扫描法相比,二者时间复杂度相同,计算结果一致,但本文方法在程序上更容易实现,且通过简单的排序比较法简化初始点集可减少凸包顶点回溯迭代次数,从而提高计算人体围度尺寸的效率。展开更多
文摘The precision controlling technology is a key step for the modern ship construction, with the precision controlling of the ship-hull curvature as one of bottlenecks in shipbuilding, where the initial is to present a compensation value for the ship-hull plate precisely. The compensation value of the curvature plate is composed of two parts: the construction compensation, which results in the process of heating construction of curvature plate, and the assembling compensation, which results in welding ribbed stiffeners onto the curvature plate. Based on the developed computation system for the local contraction value, this paper presents a method to establish the experimented samples for the assembling compensation by means of numerical experiments, and another method to establish the practical mathematical model for the construction compensation of curvature plate. Furthermore, it introduces the experimental measuring method for the assembling compensation of the curvature plate, based on which the related database system has been developed. Numerical examples are analyzed to demonstrate the process to establish mathematical model for the assembling compensation values.
文摘为适应新形势下的海上油田开发需求,以“海洋石油122”圆筒形浮式生产储卸油系统(Floating Production Storage and Offloading System,FPSO)为例,从坞内布置分析、船体分段划分方案、船体分段预制与合龙和船体管线与关键设备的安装等方面对船体建造工艺进行论述。该工艺采用全过程精度控制管理方式,确保关键设备安装精度,减少总装阶段的密闭空间作业量,大幅压缩项目工期,可为后续同类项目的开展提供技术参考。
文摘为简化围度尺寸计算过程,首先将三维人体截面点云转化到平面坐标系内,然后采用快速比较法获取点集中的4个极值点,并根据极值点将点集分成4个子区域,根据每个子区域点集的凸包具有单调性这种特性,对区域内点集的x和z坐标值进行排序比较去掉部分凹点,再通过计算点与相邻2点组成向量的叉积判断其夹角范围获取截面凸包点,将最终凸包点连接起来即为人体围度尺寸。结果表明:本文方法与 Graham 扫描法相比,二者时间复杂度相同,计算结果一致,但本文方法在程序上更容易实现,且通过简单的排序比较法简化初始点集可减少凸包顶点回溯迭代次数,从而提高计算人体围度尺寸的效率。