基于NURBS曲线和面域特性的邦戎曲线生成方法

Generation Method of Bonjean Curves Based on the NURBS Curve and the Surface Domain

相比于三次样条曲线,NURBS曲线更适于表达复杂的船型曲线。为减小传统的梯形法或辛普森法在计算面积及面积矩时所产生的累积误差,直接采用VB二次开发AutoCAD生成横剖面面域来计算。结果表明,采用面域方法所得的面积及面积矩更准确,且程序实现后二者的运行速度差异不大。最后,给出邦戎曲线生成步骤说明,并通过实例介绍该方法在船舶工程中的应用。

Compared with the cubic spline curve,the NURBS curve is more suitable for representing the complex curve of the hull cross section.In order to reduce the cumulative error resulted from the conven tional trapezoidal method or Simpson method,the VB6.0 is employed to perform the secondary develop ment on AutoCAD so that the transverse section plane is obtained,and the areas as well as the area mo ments of the hull cross section can be calculated.The result shows that the proposed method is more accu rate and equally fast in calculation than the conventional algorithm,which reveals its potential in ship engi neering.Finally,the detailed procedure of generating a Bonjean curve is summarized,and the engineering application of which is demonstrated by providing practical examples.