船体线型曲面局部修改法研究

Study on local modification method for ship hull surface

为建立一个简便、多功能的船体曲面修改和生成系统,提出一种船体线型曲面局部修改法,求解船体曲面修改问题。方法采用NURBS曲面技术,对曲面连接满足连续的充分条件推导,保证了局部曲面与外部曲面的光顺连接,控制顶点移动方程组的建立使得新曲面的表达简单直接,最后以某平台供应船船体曲面的修改为算例对方法进行验证,得到一个满足修改要求、光顺平滑的船体新曲面。该方法可应用于数字化造船和改进数学船型方法,也可推广应用于海洋平台等其他领域的曲面拟合、修改和生成。

In order to establish a local modification and design system for ship hull surface with simple operation and multipurposes,the paper proposes a local modifying method for ship hull surface.The NURBS surface technology is applied in the method.A sufficient condition for surface connection satisfying G2 continuity ensures smooth connections between the local surface and the external surface.The establishment of moving equations of control points makes the new surface expression simple and direct.Finally a case of modification for one platform supply vessel surface is given to verify the method.A new smooth hull surface which meets the demand is obtained.The method not only can be used for digital ship building and for the improvement of mathematic ship form methods,but also can be applied in other fields such as surface fitting,modification and generation.