Algorithms for Blending Surface Generation
Abstract
This thesis presents a general algorithm for the representation and approximation of blending surfaces between two non-uniform rational B-spline (NURBS) surfaces using surfaces of the same class. The algorithm permits the approximation of blending surfaces with up to curvature continuous boundary conditions along the intersection of the blending surface with the primary surfaces to be joined. These intersections are called the linkage curves. The blending surfaces are approximated by low degree Beta-spline surfaces, created using a lofting method. Isoparameter curves of the approximating blending surface are constructed based on differential geometry properties of the underlying surfaces. First derivative properties are required to satisfy tangent plane continuity boundary conditions. To satisfy curvature continuity conditions, the cross-link curves are constructed to match the curvature of a normal section of the underlying surface at the end point of the cross-link curves on the linkage curves. An adaptive sampling procedure is used to improve the approximation. Finally, the algorithm is applied to the practical problem of designing a fillet for the intersection of a marine propeller blade with a hub. An adaptation of the method which creates a standard marine propeller fillet automatically is also presented.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1991
- Accession Number
- ADA245686
Entities
People
- Peter C. Filkins
Organizations
- Massachusetts Institute of Technology