Laser Forming Oriented CAD/CAM for Developable Surfaces

2007 ◽  
Vol 344 ◽  
pp. 905-912
Author(s):  
B. Callebaut ◽  
Joost R. Duflou ◽  
Jean Pierre Kruth

Laser forming of sheet material has been widely investigated for the last 15 years. While researchers encounter severe problems during the forming of a 3D free form shape, at least one category of surfaces can be made with the process of laser forming, namely the developable surfaces, which are widely used in, for example, ship building. Those surfaces show a zero gaussian curvature and can be unrolled onto a plane without distortion. Until now, the forming of such surfaces has been more or less heuristic, but this paper aims to treat the CAD/CAM issues of this problem in a generic way. Once the surface has been defined, in order to obtain a developable surface, the surface is rebuilt into a number of planar flanges. After collision testing, the unfolding of the surface is calculated. The developable surface is scanned on the boundary between two flanges using laser settings that are determined based on efficiency optimisation considerations, keeping in mind the hardware limitations and the possible surface damage for a too high input energy. In this paper, the proposed CAD/CAM procedure is validated by means of a developable parabolic cylinder.

Author(s):  
R. M. C. Bodduluri ◽  
B. Ravani

Abstract In this paper we study Computer Aided Geometric Design (CAGD) and Manufacturing (CAM) of developable surfaces. We develop direct representations of developable surfaces in terms of point as well as plane geometries. The point representation uses a Bezier curve, the tangents of which span the surface. The plane representation uses control planes instead of control points and determines a surface which is a Bezier interpolation of the control planes. In this case, a de Casteljau type construction method is presented for geometric design of developable Bezier surfaces. In design of piecewise surface patches, a computational geometric algorithm similar to Farin-Boehm construction used in design of piecewise parametric curves is developed for designing developable surfaces with C2 continuity. In the area of manufacturing or fabrication of developable surfaces, we present simple methods for both development of a surface into a plane and bending of a flat plane into a desired developable surface. The approach presented uses plane and line geometries and eliminates the need for solving differential equations of Riccatti type used in previous methods. The results are illustrated using an example generated by a CAD/CAM system implemented based on the theory presented.


Author(s):  
B. Callebaut ◽  
Joost R. Duflou ◽  
Jean Pierre Kruth

1994 ◽  
Vol 116 (4) ◽  
pp. 1042-1048 ◽  
Author(s):  
R. M. C. Bodduluri ◽  
B. Ravani

In this paper we study Computer Aided Geometric Design (CAGD) and Manufacturing (CAM) of developable surfaces. We develop a direct representation of developable surfaces in terms of plane geometry. It uses control planes to determine a surface which is a Bezier or a B-spline interpolation of the control planes. In the Bezier case, a de Casteljau type construction method is presented for geometric design of developable Bezier surfaces. In the B-spline case, de Boor type construction for the geometric design of the developable surface and Boehm type knot insertion algorithm are presented. In the area of manufacturing or fabrication of developable surfaces, we present simple methods for both development of a surface into a plane and bending of a flat plane into a desired developable surface. The approach presented uses plane and line geometries and eliminates the need for solving differential equations of Riccatti type used in previous methods. The results are illustrated using an example generated by a CAD/CAM system implemented based on the theory presented.


2021 ◽  
Vol 111 (11-12) ◽  
pp. 797-802
Author(s):  
Leonhard Alexander Meijer ◽  
Torben Merhofe ◽  
Timo Platt ◽  
Dirk Biermann

In diesem Beitrag wird ein neuer Ansatz zum Erstellen von Maschinenprogrammen zur mikrofrästechnischen Oberflächenstrukturierung vorgestellt und die Anwendung der Prozesskette für ein komplexes, industrielles Verzahnungswerkzeug beschrieben. Durch die Reduzierung des Berechnungsaufwandes in der CAD/CAM (Computer-aided Design & Manufacturing)-Umgebung können die Limitierungen konventioneller Softwarelösungen umgangen und Bearbeitungsprogramme für komplexe Strukturierungsaufgaben effizient erstellt werden.   A new method for generating machine programs for micromilling surface structuring is presented, and the application of the process chain to a complex, industrial gearing die is described. By reducing the computational effort in the CAD/CAM (Computer-aided Design & Manufacturing) environment, the problems of conventional software solutions can be avoided and complex machining programs can be created.


2018 ◽  
Vol 175 ◽  
pp. 03067
Author(s):  
Luo Bo ◽  
Gang Zhao ◽  
Wei Wang ◽  
Xiaoxiao Du

Trimmed surfaces have been widely used in complicated product design in mechanical engineering especially in complex free form surface models of CAD/CAM/CAE. Focusing on the deficiencies of the algorithms available in published literatures when handling some intricate situations, this paper proposes a more general and efficient algorithm of trimmed surface rendering (ATSR). The ATSR is a general algorithm that can deal with most intricate situations, which frequently occur in practical engineering that no special attention has been paid to in references at hand, as well as common situations. Furthermore, this paper presents a new algorithm for the nodes of polygon connecting into elements (ANCE). The ANCE can handle most tricky polygons appearing in the process of rendering and achieve successful triangulation for the to-be-rendered surface. Preferable results are obtained in the case studies, which indicate that the algorithms (ATSR and ANCE) are efficient and effective in handling complicated as well as common trimmed surface models in real engineering industry.


Author(s):  
Jack Chang ◽  
Mark Ganter ◽  
Duane Storti

Abstract Computer-aided design/manufacturing (CAD/CAM) systems intended to support automated design and manufacturing applications such as shape generation and solid free-form fabrication (SFF) must provide not only methods for creating and editing models of objects to be manufactured, but also methods for interrogating the models. Interrogation refers to any process that derives information from the model. Typical interrogation tasks include determine surface area, volume or inertial properties, computing surface points and normals for rendering, and computing slice descriptions for SFF. While currently available commercial modeling systems generally employ a boundary representation (B-rep) implementation of solid modeling, research efforts have considered implicit modeling schemes as a potential source of improved robustness. Implicit implementations are available for a broad range of modeling operations, but interrogation operations have been widely considered too costly for many applications. This paper describes a method based on interval analysis for interrogating implicit solid models that aims at achieving both robustness and efficiency.


Author(s):  
Zezhong C. Chen ◽  
Gang Liu

As important components of gas turbine engines, axial-flow compressors have been improved with a more complex and accurate airfoil design to meet high aerodynamic requirements; specifically, the pressure and suction surfaces of the airfoils (or blades) are now represented with free-form surfaces in CAD software systems. Since quality of the blades affects efficiency of the engines and safety of the aircrafts, some types of compressors are produced with the blades and the hub as a single piece on 4-axis CNC milling machines. However, it is still quite challenging to automatically determine cutter sizes and orientations without gouging and interference during the 4-axis milling, because the geometric shape of the blades is complex and the blades overlap with each other. As a result, the established method of determining tool size and orientation in industry is by trial and error in a repetitive process of selecting cutters and planning tool-paths with CAM systems. To address this problem, a novel approach is proposed to automatically determine cutter sizes and orientations for 4-axis milling of the axial-flow compressors blades without gouging and interference. The main contribution of this work is that (1) a mathematical model for optimizing cutter sizes in 4-axis milling is established; and (2) by applying a global optimization method — the particle swarm optimization method — to this model, the maximum allowable size of a cutter and its corresponding orientation can be found at each cutter-contact (CC) point on the surface being machined. Therefore, all the maximum allowable sizes of cutters for all the CC points and the corresponding cutter orientations can be computed. A group of standard cutters are then selected; each of which can sweep particular CC points without damaging the compressor. Since it is efficient and reliable, this newly proposed approach can be directly implemented in commercial CAD/CAM software systems to benefit the manufacturing industry.


Author(s):  
Kotaro Yoshida ◽  
Hidefumi Wakamatsu ◽  
Eiji Morinaga ◽  
Takahiro Kubo

Abstract A method to design the two-dimensional shapes of patterns of two piece brassiere cup is proposed when its target three-dimensional shape is given as a cloud of its data points. A brassiere cup consists of several patterns and their shapes are designed by repeatedly making a paper cup model and checking its three-dimensional shape. For improvement of design efficiency of brassieres, such trial and error must be reduced. As a cup model for check is made of paper not cloth, it is assumed that the surface of the model is composed of several developable surfaces. When two lines that consist in the developable surface are given, the surface can be determined. Then, the two-piece brassiere cup can be designed by minimizing the error between the surface and given data points. It was mathematically verified that the developable surface calculated by our propose method can reproduce the given data points which is developable surface.


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