Abstract
Keywords
Surface Modeling, Class-A surface, Autobody
Abstract
There are many studies about how to create a smooth or fairing surface, and also there are many papers on the geometry continuity between two or three connective patches. Especially, in mathematics, we can find a lot of theories and algorithms about above items. Based those theories, there are several good surface software packages, such as ICEM Surf of PTC, CATIA, UG, etc. How to create a Class-A model of Autobody using the easy-to-use CAD tools, is the focus of this paper.
When talking about surface fairness, we think the "three principles", that is the curvature continuity, equal curvature change, and energy minimization, but due to the development of computer technology, the surface modeling technology is mainly base on NURBS representation. So the new principles should be formed. In the Autobody design field, the Class-A surface is subset of fairness surfaces.
The paper brings about new fairing criterion with five principles of Autobody Class-A surface, such as based-NURBS representation method, all convex or concave patches, the limitation order of u, v direction, uniformly distribution of the curvature comb, no much peak points and inflection points. And then this paper depicts the creation method and the techniques when using this method; finally, the paper gives some examples of Autobody panels based on above principles.
The practical method is helpful to get Class-A model of Autobody quickly, and it will reduce the check work and speedup the analysis process and NC programming. Eventually, it improves the quality of the Autobody products.