Feature-Based Crystal Construction in Computer-Aided Nano-Design

2008 ◽  
Author(s):  
Cheng Qi ◽  
Yan Wang
Keyword(s):  
Material Design ◽  
Surface Model ◽  
Periodic Surface ◽  
Periodic Surfaces ◽  
Nano Structures ◽  
Rapid Construction ◽  
Computer Aided ◽  
Feature Based ◽  
Basic Features ◽  
Complex Crystal

Providing nano engineers and scientists efficient and easy-to-use tools to create geometry conformations that have minimum energies is highly desirable in material design. Recently we developed a periodic surface model to assist the construction of nano structures parametrically for computeraided nano-design. In this paper, we present a feature-based approach for crystal construction. The proposed approach starts to create models of basic features by the aide of periodic surfaces followed by operations between basic features. The goal is to introduce a rapid construction method for complex crystal structures.

Degree Operations on Periodic Surfaces

2007 ◽  
Author(s):  
Yan Wang
Keyword(s):  
Surface Model ◽  
Implicit Surface ◽  
Periodic Surface ◽  
Degree Elevation ◽  
Periodic Surfaces ◽  
Computer Aided ◽  
Particle Aggregates

In previous work, a periodic surface model for computer-aided nano-design (CAND) was developed. This implicit surface model can construct Euclidean and hyperbolic nano geometries parametrically and represent morphologies of particle aggregates and polymers. In this paper, we study the characteristics of degree elevation and reduction based on a generalized periodic surface model. Methods of degree elevation and reduction operations are developed in order to support multi-resolution representation and model exchange.

Minkowski Sums of Periodic Surface Models

2009 ◽  
Author(s):  
Yan Wang
Keyword(s):  
Crystal Packing ◽  
Surface Model ◽  
Implicit Surface ◽  
Periodic Surface ◽  
Construction Methods ◽  
Periodic Surfaces ◽  
Nano Structures ◽  
Surface Models ◽  
Minkowski Sums ◽  
Volume Translation

Recently we proposed a periodic surface model to assist geometric construction in computer-aided nano-design. This implicit surface model helps create super-porous nano structures parametrically and support crystal packing. In this paper, we study construction methods of Minkowski sums for periodic surfaces. A numerical approximation approach based on the Chebyshev polynomials is developed and can be applied in both surface normal direction matching and volume translation formulations.

3D Fractals From Periodic Surfaces

2010 ◽  
Author(s):  
Yan Wang
Keyword(s):  
Porous Silicon ◽  
Iterated Function Systems ◽  
Surface Model ◽  
Porous Structures ◽  
Implicit Surface ◽  
Periodic Surface ◽  
Irregular Structures ◽  
Periodic Surfaces ◽  
Iterated Function ◽  
3D Fractals

Fractals are ubiquitous as in natural objects and have been applied in designing porous structures such as micro antenna and porous silicon. The seemingly complex and irregular structures can be generated based on simple principles. In this paper, we present three approaches to construct 3D fractal geometries using a recently proposed periodic surface model. By applying iterated function systems to the implicit surface model in the Euclidean or parameter space, 3D fractals can be constructed efficiently. Porosity is also proposed as a metric in fractal design.

Machining Feature-Based CAD/CAPP for STEP-NC

2014 ◽  
Vol 598 ◽  
pp. 591-594 ◽  
Author(s):  
Li Yan Zhang
Keyword(s):  
Process Planning ◽  
Manufacturing Process ◽  
Data Transfer ◽  
Operation Planning ◽  
Computer Aided Process Planning ◽  
Machining Feature ◽  
Computer Aided ◽  
Cad Cam ◽  
Feature Based ◽  
Cam Systems

ISO 14649, known as STEP-NC, is new model of data transfer between CAD/CAM systems and CNC machines. In this paper, the modeling based on machining feature is proposed. The machining feature comes from the manufacturing process considering the restriction of machining technology and machining resource. Then the framework for computer aided process planning is presented, where the algorithms of operation planning is studied. The practical example has been provided and results indicate that machining feature based model can integrate with CAPP and STEP-NC seamlessly.

A statistical method for build orientation determination in additive manufacturing

2019 ◽  
Vol 25 (1) ◽  
pp. 187-207 ◽  
Author(s):  
Yicha Zhang ◽  
Ramy Harik ◽  
Georges Fadel ◽  
Alain Bernard
Keyword(s):  
Additive Manufacturing ◽  
Statistical Method ◽  
Supervised Machine Learning ◽  
Surface Model ◽  
Generic Level ◽  
Content Type ◽  
Build Orientation ◽  
Cad Models ◽  
Feature Based ◽  
Orientation Determination

Purpose For part models with complex shape features or freeform shapes, the existing build orientation determination methods may have issues, such as difficulty in defining features and costly computation. To deal with these issues, this paper aims to introduce a new statistical method to develop fast automatic decision support tools for additive manufacturing build orientation determination. Design/methodology/approach The proposed method applies a non-supervised machine learning method, K-Means Clustering with Davies–Bouldin Criterion cluster measuring, to rapidly decompose a surface model into facet clusters and efficiently generate a set of meaningful alternative build orientations. To evaluate alternative build orientations at a generic level, a statistical approach is defined. Findings A group of illustrative examples and comparative case studies are presented in the paper for method validation. The proposed method can help production engineers solve decision problems related to identifying an optimal build orientation for complex and freeform CAD models, especially models from the medical and aerospace application domains with much efficiency. Originality/value The proposed method avoids the limitations of traditional feature-based methods and pure computation-based methods. It provides engineers a new efficient decision-making tool to rapidly determine the optimal build orientation for complex and freeform CAD models.

An Interactive CAPP Kernel Based on a Blackboard System Architecture

1996 ◽  
Author(s):  
Jean-Pierre Kruth ◽  
Geert Van Zeir ◽  
Jan Detand
Keyword(s):  
Process Planning ◽  
System Architecture ◽  
Human Operator ◽  
Computer Aided Process Planning ◽  
Full Control ◽  
Computer Aided ◽  
Feature Based ◽  
Blackboard System ◽  
Planning Task ◽  
Reasoning Mechanism

Abstract This paper describes the ideas and developments that lead to a new Computer Aided Process Planning (CAPP) approach : a blackboard-style, interactive CAPP system, in which the human process planner is assisted by expert modules, each capable of performing a process planning task. At all times, the human operator has full control over all planning activities. An important reasoning mechanism, that is inevitably linked with the interactive CAPP kernel, is opportunistic process planning. The implementation of this mechanism in an automatic feature based CAPP system will also be elaborated in this paper.

Parting Line Formation by Slicing a Trimmed Surface Model

1996 ◽  
Author(s):  
T. Wong ◽  
S. T. Tan ◽  
W. S. Sze
Keyword(s):  
Product Design ◽  
Free Form ◽  
Surface Model ◽  
Curved Surfaces ◽  
Line Formation ◽  
Planar Surfaces ◽  
Manufacturing Efficiency ◽  
Computer Aided ◽  
Trimmed Surface ◽  
Free Form Surfaces

Abstract The parting line on a product affects the final layout of the mould blocks and hence the manufacturing efficiency. The increased usage of free-form surfaces in product design increases the burden of computer aided parting line and parting surface determination. Previous proposed algorithms may not be sufficient to deal with such situation since most of them were originally designed to deal with products having planar surfaces or simple curved surfaces. A new algorithm is proposed to deal with such situation. The algorithm adopted a recursive uneven slicing on a trimmed surface model. The method provides a quick and efficient way of locating the parting line of a product.

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