Computer Aided Hull Design

COURSE TEACHER

Dr. Md. Mashud Karim

Professor

Dept. of Naval Architecture and Marine Engineering

Bangladesh University of Engineering & Technology

NAME 6303: COMPUTER AIDED HULL DESIGN 3 CREDIT, 3 HRS./WK.

DETAILED SYLLABUS

Analytic representation of a curve Advanced interpolation and control polygon techniques, Bezier and B-spline approximations, B-spline curve fitting. Form parameter of curves, Development of lines plan,

Parametric surface representation, Blend generation, Partial differential equation (PDE) method for surface generation, Free form surface generation, Bezier surfaces, B-spline surfaces, Non-uniform rational B-spline (NURBS) surfaces, Surface design with volume constraints, Gaussian curvature and surface fairness. Generation and optimization of ship hull and propeller blade geometry.

Suggested Books

Curves and Surfaces for CAGD, Fifth Edition: A Practical Guide (The Morgan Kaufmann Series in Computer Graphics... by Gerald Farin (Nov 5, 2001)

Computational Geometry for Ships by H. Nowacki, M. I. G. Bloor and B. Oleksiewicz (Apr 1995)

Mathematical Elements for Computer Graphics by David F. Rogers and J.Alan Adams (Nov 1, 1989)

Computer Aided Geometric Design

Computer-aided geometric design deals with the mathematical description of

shape for use in computer graphics, numerical analysis, approximation theory, data

structures, and computer algebra.

In principle, students should just get familiar with some specific design applications, such as Rhino3D, Maxsurf, Foran,... But a thorough knowledge of their capabilities comes from learning at least the algorithms that lie behind the application, even if the students are not to become developers themselves.

Computer-Aided Geometric Design(CAGD) is the basis for modern design in most branches of industry, from naval architecture and aeronautic to textile industry.

In recent decades, mathematical methods of computational geometry have made much progress and are successfully applied in many engineering disciplines

Computer Aided Hull Design

The objective of this course is to review the mathematical background needed to understand the methods used by modern computer systems for ship design and manufacture

Computer Aided Hull Design (CAHD) is a specialized branch of CAGD.

Parametric Curve representation

A familiar way of representing a plane curve by using explicit non-parametric equations of the form y=f(x).

However, CAGD, it is more common to define curves parametrically in terms of a single scalar parameter.

Example

•  Synthetic curves include various types of splines (cubic spline, B-spline, Beta-spline) and Bezier curves.

Analytic Curves •  Analytic Curves are points, lines, arcs and circles, fillets and chamfers, and conics (ellipses, parabolas, and hyperbolas)

Synthetic Curves

Analytic Curves vs. Synthetic Curves

Drafting Spline

Fig.: Physical Spline and ducks

Spline

A Bezier curve is determined by a defining polygon as shown in the figure.

Properties of Bezier Cureve