A Study On WPC Hull Lines Based On Parametric Design Method

Nowadays, routine ship hull lines drawing has been basically mature with rich correlative design software systems, gradually reaching 3D design mode based on curve surface. Relatively speaking, compared with hull lines of traditional routine ships, WPC s have great differences in its short development history and military secrecy, with quite limited reference materials published, therefore, new ship forms cannot be established through reconstruct original ship form with 1-Cp, Lcakenby or function change methods.According to existing references, there' s not any method or software for WPC hull lines drawing. Therefore, in practical work, adjustments and revision can only be completed based on designers' intuition and experiences via drawing software, which may result in inefficiency and inaccuracy in the process of hull lines design and its improvement. Thus a programming method particularly for WPC hull lines drawing and change will be of great theoretical and application value. Concerned with this significance, the author has studied and achieved in the paper, as followed:(1) Analyzed the characteristics of WPC hull lines, chose the hull lines drawing under water line as the study object, gave concrete design parameters of WPC.(2) Described area curve of transverse section, half-width knuckle line and half-breath waterline via non-uniform B-Spline, which can dynamically revise, add or delete quality points and control points on the curve, and revise the shape of the curve through changing two-end tangent vectors. This can bring the designers more flexibility.(3) Research its concrete hull lines design methods after establishing WPC mathematical model. Given certain measures, this method will firstly complete the design of feature lines such as profile curve, keel line, knuckle line etc., then design transverse section area curve, half-breath knuckle line, half-breath waterline, and get a series of harmonious body lines along ship-length direction after adapting displacement, LCB and LFC to design values. Thus revise correlative design parameters, and the designers can gain various ship form design projects, which will provide the foundation for the following general arrangement, stability checking,structure calculation and hydrokinetic hydrodynamic etc.(4) Design result will be transformed into hull lines plan using AutoCAD platform, and the designers may put into offsets and conveniently revise or print it.(5) With AutoCAD2004 as the platform, Visual Basic6.0 as programming tool, this paper deeply investigates the applications of correlative techniques of AutoCAD secondary development in WPC hull lines design, including self-creation from offsets to hull lines, 3D fairing of hull lines in AutoCAD, automatic creations of 3D net grid, 3D entity and hull lines value diagrams for the designers.