On the Integration of Parametric Polynominal Surface Representations Into CSG Based Solid Modelling

1989 ◽  
Author(s):  
A. Saia ◽  
M. S. Bloor ◽  
A. de Pennington
Keyword(s):  
Shape Representation ◽  
Sculptured Surface ◽  
Constructive Solid Geometry ◽  
Solid Modelling ◽  
Surface Geometry ◽  
B Spline ◽  
Spline Surface ◽  
Solid Geometry ◽  
Modelling Techniques ◽  
Surface Representations

Abstract The integration of sculptured surface and solid modelling techniques across a common geometric domain continues as an active source of research and development in computer aided geometric design. Although much progress has been made, fundamental difficulties remain due to the differing approaches to shape representation and subsequent evaluation found in the two modelling paradigms. The first part of the paper reviews some of the issues arising when addressing the integration of existing sculptured surface representations into a Constructive Solid Geometry (CSG) based solid modeller. The second part describes work at Leeds which proposes the use of a new evaluation technique known as ISOS (Inner Set Outer Set) for CSG defined objects which incorporate both quadric and B-spline surface geometry.

Integration of Solid Modelling and FEM Analysis for the Design of Scroll Compressors

1999 ◽  
Author(s):  
Z. Jiang ◽  
K. Cheng ◽  
D. K. Harrison
Keyword(s):  
Fem Analysis ◽  
Constructive Solid Geometry ◽  
Solid Modelling ◽  
Design Development ◽  
Air Conditioners ◽  
Solid Geometry ◽  
Integration Approach ◽  
C Programming ◽  
Design And Manufacture ◽  
Associated Design

Abstract This paper presents an integration approach to solid modelling and finite element method (FEM) analysis on the components design of a scroll type of compressors which are becoming popular and widely used in refrigeration and air conditioners. It is time consuming to design and manufacture a scroll compressor since its two key components are complex shaped and high precision requirements. The authors use C++ programming and Pro/ENGINEER to implement the proposed approach and associated design development. Constructive solid geometry (CSG) modelling of two scroll components are created and presented. FEM analysis is used to further consolidate the modelling with respect to force and heat influences, etc. The paper concludes with a discussion on the potential of the proposed approach in mechanical product design.

NC Machining Algorithms for CSG Solids

1987 ◽  
Author(s):  
S. T. Tan ◽  
M. F. Yuen ◽  
W. S. Sze ◽  
W. Y. Wong
Keyword(s):  
Numerical Control ◽  
Constructive Solid Geometry ◽  
Solid Modelling ◽  
Rough Machining ◽  
Command Language ◽  
Numerical Control Machining ◽  
Solid Geometry ◽  
Set Up ◽  
Automation Project ◽  
Production Automation

Abstract This paper presents two algorithms for NC (Numerical Control) machining of engineering parts defined as a CSG (Constructive Solid Geometry) (1) model. The algorithms are respectively for automatically roughing out the approximate shape using octree and quadtree encoding techniques and for machining the final shape with fine cuts. In this paper, the two algorithms are referred to as rough machining and fine machining and form the Hong Kong University’s NC module for the PADL-2 solid modelling system developed by the Production Automation Project of Rochester University. The NC module with its own command language is embedded into PADL-2. Parts defined with the PADL-2 system can be machined using this module on a 3-axis machining centre via a hardwired link. Examples of the parts machined with this set-up are also illustrated in this paper.

An Inverse Hull Design Problem in Optimizing the Desired Wake of a Ship

2002 ◽  
Vol 46 (02) ◽  
pp. 138-147
Author(s):  
Po-Fan Chen ◽  
Cheng-Hung Huang
Keyword(s):  
Design Problem ◽  
Control Points ◽  
Surface Geometry ◽  
Hull Form ◽  
B Spline ◽  
Spline Surface ◽  
Surface Method ◽  
Commercial Code ◽  
Hull Design ◽  
Inverse Hull

An inverse hull design problem for optimizing the shape of the after hull based on the desired wake distribution is solved using the Levenberg-Marquardt Method (LMM) and the commercial code SHIPFLOW. The desired wake distribution on a propeller plane can be obtained by modifying the existing wake distribution of the parent ship. The surface geometry of the ship is generated using the B-spline surface method, which enables the shape of the hull to be completely specified with only a small number of parameters (i.e., the control points). The advantage of calling SHIPFLOW as a subroutine in the present inverse calculation lies in that many difficult but practical hydrodynamic problems regarding ship design can be solved under this construction. The validity of the present 3-D inverse hull design problem for the after hull of a ship is justified based on the numerical experiments. Results show that optimal hull form can always be obtained based on the required wake distributions.

A polymorphic library for constructive solid geometry

1995 ◽  
Vol 5 (3) ◽  
pp. 415-442
Author(s):  
J. R. Davy ◽  
P. M. Dew
Keyword(s):  
Higher Order ◽  
Divide And Conquer ◽  
Functional Language ◽  
Constructive Solid Geometry ◽  
Solid Modelling ◽  
General Applicability ◽  
Solid Geometry ◽  
Recurrent Patterns ◽  
Higher Order Functions

AbstractSolid modelling using constructive solid geometry (CSG) includes many examples of stylised divide-and-conquer algorithms. We identify the sources of these recurrent patterns and describe a Geometric Evaluation Library (GEL) which captures them as higher-order functions. This library then becomes the basis of developing CSG applications quickly and concisely. GEL is currently implemented as a set of separately compiled modules in the pure functional language Hope+. We evaluate our work in terms of performance and general applicability. We also assess the benefits of the functional paradigm in this domain and the merits of programming with a set of higher-order functions.

scholarly journals Complex Uncertainty of Surface Data Modeling via the Type-2 Fuzzy B-Spline Model

Mathematics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1054
Author(s):  
Rozaimi Zakaria ◽  
Abd. Fatah Wahab ◽  
Isfarita Ismail ◽  
Mohammad Izat Emir Zulkifly
Keyword(s):  
Complex Surface ◽  
Complex Data ◽  
Fuzzy Data ◽  
Control Points ◽  
B Spline ◽  
Spline Surface ◽  
Data Control ◽  
Surface Data ◽  
Model Complex

This paper discusses the construction of a type-2 fuzzy B-spline model to model complex uncertainty of surface data. To construct this model, the type-2 fuzzy set theory, which includes type-2 fuzzy number concepts and type-2 fuzzy relation, is used to define the complex uncertainty of surface data in type-2 fuzzy data/control points. These type-2 fuzzy data/control points are blended with the B-spline surface function to produce the proposed model, which can be visualized and analyzed further. Various processes, namely fuzzification, type-reduction and defuzzification are defined to achieve a crisp, type-2 fuzzy B-spline surface, representing uncertainty complex surface data. This paper ends with a numerical example of terrain modeling, which shows the effectiveness of handling the uncertainty complex data.

Generation and Modification of Non-Uniform B-Spline Surface Approximations to PDE Surfaces Using the Finite Element Method

1990 ◽  
Author(s):  
Joanna M. Brown ◽  
Malcolm I. G. Bloor ◽  
M. Susan Bloor ◽  
Michael J. Wilson
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Spline Approximation ◽  
The Finite Element Method ◽  
B Spline ◽  
B Splines ◽  
Spline Surface ◽  
Spline Surfaces ◽  
Spline Basis ◽  
Element Method

Abstract A PDE surface is generated by solving partial differential equations subject to boundary conditions. To obtain an approximation of the PDE surface in the form of a B-spline surface the finite element method, with the basis formed from B-spline basis functions, can be used to solve the equations. The procedure is simplest when uniform B-splines are used, but it is also feasible, and in some cases desirable, to use non-uniform B-splines. It will also be shown that it is possible, if required, to modify the non-uniform B-spline approximation in a variety of ways, using the properties of B-spline surfaces.

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