bluuebunny/crossref_metadata_2025_split huggingface dataset:
Representing and Manipulating Interacting and Interfeature Relationships in Engineering Design for Manufacture
Authors: da Silva R. E. , Wood K. L. , Beaman J. J. 
Published: April 2021

Abstract
The objective of design for manufacture is to sever the dichotomy of design and manufacturing practices so that these two areas will be pursued as a homogeneous activity. Many issues are important for this “marriage” of design and manufacturing: the representation of manufacturing information for reasoning in the early stages of a design; the development of computer-aided tools for process planning, tolerance design and analysis, and automatic assembly; the formulation of design systems to facilitate reasoning about the topology and geometric structure of mechanical parts; etc. In this paper, a strategy for the representation and manipulation of spatial relationships between features is described. A language, made up of a set of primitives (lexical icons and geometric concepts), is developed for the domain of standard cavity-type features encountered in discrete parts manufacturing. A formal methodology is subsequently discussed for modeling these features in the context of interacting and interfeature relationships. Two applications, in the areas of fixture design and process planning, illustrate the utility of the formalism.
A Prototype of Feature-Based Design for Assembly
Authors: DeFazio T. L. , Edsall A. C. , Gustavson R. E. , Hernandez J. A. , Hutchins P. M. , Leung H.-W. , Luby S. C. , Metzinger R. W. , Nevins J. L. , Tung K. K. , Whitney D. E. 
Published: April 2021

Abstract
This paper describes a prototype software system that implements a form of feature-based design for assembly. It is not an automated design system but instead a decision and design aid for designers interested in Concurrent Design. Feature-based design captures design intent (assembly topology, product function, manufacturing, or field use) while creating part and product geometry. Design for assembly as used here extends existing ideas about critiquing part shapes and part count to include assembly process planning, assembly sequence generation, assembly fixturing assessments, and assembly process costs. This work was primarily Interested in identifying the information important to DFA tasks, and how that information could be captured using feature-based design. It was not intended to extend the state of the art in feature-based geometry creation, but rather to explore the uses of the information that can be captured. The prototype system has been programmed in LISP on Sun workstations. Its research contributions comprise integration of feature-based design with several existing and new assembly analysis and synthesis algorithms; construction of feature properties to meet the needs of those algorithms; a carefully chosen division of labor between designer and computer; and illustration of feature-based models of products as the information source for assembly analysis and process design. Some of its functions have been implemented approximately or partially but they give the flavor of the benefits to be expected from a fully functional system.
A Design System for Parametric Design of Complex Products
Authors: Malmqvist Johan 
Published: April 2021

Abstract
In this report a design system for parametric design of complex products is presented. The system is based on product models for complex products and components. These models were implemented as general framework models using the data base management system TORNADO. The user creates models for specific products by filling out forms. Consequently, all products can be represented in a uniform way. This gives the advantage that all service software (for storage in the product data base, retrieval of component data etc.) associated to a certain product model can be shared. The only lines of code the designer writes when creating a new component family are the design rules of the component. In association with the models a design system for complex products is presented. Benefitting from the uniform representations of the products, the system lets the user control the design process, while a system kernel handles the constraint management.
The product models and the design system have been applied to hydraulic cylinder design.
The Use of Algebraic Functions As a Solid Modeling Alternative: An Investigation
Authors: Blechschmidt James L. , Nagasuru D. 
Published: April 2021

Abstract
An investigation of surface and solid modeling using a single unbounded algebraic function for objects requiring free form surfaces is discussed. The purpose of this investigation is to determine if a single closed algebraic function can be effectively used to represent objects. Curve fitting techniques are developed. Surfaces using implicit algebraic functions are developed using the techniques of revolution about an axis and extrusion along a curve segment. Infinite extrusions of a planar cross section along an axis of the form y = f(x) are developed. The boolean operators of union, intersection, and difference are developed using the defining function form of algebraic functions. All of the operations have been accomplished in algebra using polynomial multiplication, addition, and subtraction. Examples of all the operations are presented.
The Curve-Mesh Concept in Reconstructing Smooth Surface From Noisy Data
Authors: Kaklis P. D. 
Published: April 2021

Abstract
This paper is concerned with the problem of filtering the noise encountered in the measurements taken from a smooth (GC2-continuous) surface in the three-dimensional space. For this purpose, the data points are firstly considered to belong to a three-dimensional entity which is drastically simpler than a surface, namely the noisy curvature-continuous quadrilateral curve-mesh connecting the data points. The curve-mesh concept, apparently introduced by Hosaka (1969), is then combined with the concept of fairing in a statistical framework introduced by Reinsen (1967; 1971), yielding a constrained minimization problem for the fairing curve-mesh. After establishing that this problem has a unique solution in an appropriate Hilbert space, a convergent Newton-Raphson-type algorithm for constructing it in a cubic-spline subspace is presented in detail. Finally, the numerical performance of this algorithm in the context of a Monte-Carlo experimentation with the so-called Franke’s principal test function (1979,1980,1982) is discussed.
Topological and Geometric Consistency in Boundary Representations of Solid Models
Authors: Jablokow Andrei G. , Uicker John J. , Turcic David A. 
Published: April 2021

Abstract
This paper describes a method of verifying the consistency between the topology and geometry of boundary representation (B-rep) of solid models. This verification is well suited for implementation as an algorithm and has been implemented as such in a polyhedral boundary representation solid modeling system (Jablokow 1989). Information regarding boundary representations is typically divided into the geometry and topology. It is important that the two are consistent for a valid solid model. In this work the genus of an object is calculated topologically and geometrically and then compared to verify the consistency of the solid model. The genus of an object gives insight as to the geometric complexity of the object. This is equivalent to verifying the Gauss-Bonnet Theorem for the model, and is discussed in the paper.
A Geometric Investigation of the Skeleton of CSG Objects
Authors: Dutta Debasish , Hoffmann Christoph M. 
Published: April 2021

Abstract
We sketch an algorithm for computing the skeleton (medial-axis surface) of an object defined using constructive solid geometry (CSG). The skeleton can be used in blending, motion planning, medical tomography, computer vision, and in mesh generation. We also present a geometric analysis of Voronoi surfaces from which the skeleton is composed, for a large number of surface pairs arising often in practice.
An Interactive Graphical Approach to Feature Modeling Using Halfspaces and Geometric Constraints
Authors: van Emmerik Maarten J. G. M. 
Published: April 2021

Abstract
Feature modeling enables the specification of a model with standardized high-level shape aspects that have a functional meaning for design or manufacturing. In this paper an interactive graphical approach to feature-based modeling is presented. The user can represent features as new CSG primitives, specified as a Boolean combination of halfspaces. Constraints between halfspaces specify the geometric characteristics of a feature and control feature validity. Once a new feature is defined and stored in a library, it can be used in other objects and positioned, oriented and dimensioned by direct manipulation with a graphics cursor. Constraints between features prevent feature interference and specify spatial relations between features.
Decomposition of Measured Contours Into Geometric Features
Authors: Etesami Faryar , Rajkumar Devaraj 
Published: April 2021

Abstract
In dimensional measurement applications where the object boundary data is indiscriminately collected, the need for detecting transition points from one feature to another arises. In addition, measured features must be matched with their corresponding nominal counterparts. In this paper, a solution to this problem is presented for planar contours which are composed of straight and circular edges. Two algorithms are presented, the first algorithm detects the transition points involving straight edges and the second algorithm finds the transition points between circular edges. The performance of these algorithms are demonstrated by simulated as well as actual part measurements.
Tolerances and Robustness in Engineering Design Optimization
Authors: Parkinson Alan , Sorensen Carl , Free Joseph , Canfield Bradley 
Published: April 2021

Abstract
This paper describes a new strategy for incorporating tolerances as part of engineering design optimization. The tolerance problem is defined in a general way that allows for tolerances on all model variables and parameters and includes worst case and statistical analysis. Two methods are described for taking tolerances into account during optimization such that an optimal design will remain feasible despite fluctuations in variables or parameters. Methods are also presented for directly controlling transmitted variation, and a framework for optimal tolerance allocation is proposed.
Dynamic 3-D Visualization of Dimensions and Tolerances on Solid Models Using ANSI Standard
Authors: Dori Dov , Miller James R. 
Published: April 2021

Abstract
The use of current solid modelers as a comprehensive MCAE system is hampered by the lack of proper annotation capabilities, primarily dimensioning and tolerancing (D&T). An initial design done on a solid modeler must be transferred to some wire-frame module for D&T annotation and analysis and for blueprint production. We propose a solid modeler which has D&T capabilities that will eventually enable a complete design cycle. Dimensions and size tolerances that follow the ANSI D&T standard are treated as objects in 3D that are attached to relevant object features. We discuss implementation issues and show how ANSI-based blueprints can be genereted directly from the solid modeler.
Computer-Assisted Pattern Development
Authors: Ganter M. A. , Tuss L. L. 
Published: April 2021

Abstract
Patternmaking and moldmaking are the first stages in a casting process whether the materials involved are either metals or plastics. The development of a pattern is a crucial part of the overall molding process. Results from an investigation to automate the process of patternmaking will be presented. This investigation focussed on three major areas; development of a rule-set for parting, parting search strategies, and back draft detection. While no “official” set of parting rules exists today, a collection of rules was developed using various sources of casting literature and in plant pattern surveys. Using this rule set, a parting procedure was developed which was realized through the use of computers and solid modeling technology. Results from these procedures have proven successful enough to warrant continued research in automated pattern design.
Efficient Intersection of Surface Normals With Milling Tool Swept Volumes for Discrete Three-Axis NC Verification
Authors: Oliver James H. 
Published: April 2021

Abstract
An efficient algorithm is presented for intersecting vectors with swept solids which represent three-axis numerically controlled (NC) milling tool motions. The intersection calculation proceeds in hierarchical steps through a series of progressively more exact definitions of the shape of the tool swept volume. At each step, results of intermediate calculations are used to determine whether intersection with an exact representation of the solid is possible and, if so, where and how the swept volume model must be refined for the next step. This structure ensures that superfluous intersection calculations are minimized. This intersection technique has been successfully implemented as part of an algorithm for automatic verification of three-axis NC milling programs, and may also be useful for applications in robotics and factory automation.
Computational Geometry on the Sphere With Application to Automated Machining
Authors: Chen Lin-Lin , Woo Tony C. 
Published: April 2021

Abstract
Based on observations made on the geometry of the cutting tools and the degrees of freedom in 3-, 4-, 5-axis numerical control machines, a new class of geometric algorithms is induced — on the unit Sphere. Spherical algorithms are useful for determining the type of tool, its path, workpiece fixturing, and the type of machine.
Basic to these algorithms are four that are presented here: detection of convexity on the sphere, computation for spherically convex hull, determination of the spherical convexity of a union and the intersection of hemispheres. These four algorithms are related by duality and the sharing of partial results.
Collision-Free Path Planning by Using Non-Periodic B-Spline Curves
Authors: Yang D. C. H. 
Published: April 2021

Abstract
This paper presents a method and a algorithm for the planning of collision-free paths through obstacles for robots end-effectors or autonomously guided vehicles. Fifth-order non-periodic curves are chosen for this purpose. The main ideas are twofold: firstly, to avoid collision by moving around obstacles from the less blocking sides; and secondly, to assign two control points to all vertices of the control polygon. This method guarantees the generation of paths which have C3 continuity everywhere and satisfy the collision-free requirement. In addition, the obstacles can be of any shape, and the computational complexity and difficulty are relatively low. A computer code is developed for the implementation of this method. Cases study is given for illustration.
Automatic Generation of Tolerance Chains From Mating Relations Represented in Assembly Models
Authors: Wang Nanxin , Ozsoy Tulga M. 
Published: April 2021

Abstract
This paper presents an algorithm for generating tolerance chains from the mating relations between components of assemblies. The algorithm is developed upon a feature-based assembly modeling strategy that represents each component in close relation to its mating features, dimensions and tolerances. The mating relations within an assembly are described by a mating graph. Tolerance chains together with their dimensions and tolerances are generated automatically by searching through a mating graph for matching mating features. A prototype program package based on the presented algorithm has been developed, and several examples of various complexity have been tested with success.
Designing and Mapping Trimming Curves on Surfaces Using Orthogonal Projection
Authors: Pegna Joseph , Wolter Franz-Erich 
Published: April 2021

Abstract
In the design and manufacturing of shell structures it is frequently necessary to construct trimming curves on surfaces. The novel method introduced in this paper was formulated to be coordinate independent and computationally efficient for a very general class of surfaces. Generality of the formulation is attained by solving a tensorial differential equation that is formulated in terms of local differential properties of the surface.
In the method proposed here, a space curve is mapped onto the surface by tracing a surface curve whose points are connected to the space curve via surface normals. This surface curve is called to be an orthogonal projection of the space curve onto the surface. Tracing of the orthogonal projection is achieved by solving the aforementionned tensorial differential equation. For an implicitely represented surface, the differential equation is solved in three-space. For a parametric surface the tensorial differential equation is solved in the parametric space associated with the surface representation. This method has been tested on a broad class of examples including polynomials, splines, transcendental parametric and implicit surface representations.
Orthogonal projection of a curve onto a surface was also developed in the context of surface blending. The orthogonal projection of a curve onto two surfaces to be blended provides not only a trimming curve design tool, but it was also used to construct smooth natural maps between trimming curves on different surfaces. This provides a coordinate and representation independent tool for constructing blend surfaces.
Computer Aided Geometric Design of Line Constructs
Authors: Ravani B. , Wang J. W. 
Published: April 2021

Abstract
This paper develops a mathematical foundation for Computer Aided Design (CAD) of sculptured shapes based on line geometry. First, a new representation is presented for a line based on Plücker coordinates that would allow specification of a line segment (rather than an infinite line) in an elegant manner and suitable for computational purposes. Then, methods are presented for geometric design of shape patches (here referred to as line constructs) by interpolating or approximating a set of control lines (rather than control points) using ruled surfaces, line congruences and line complexes. The methods presented are general and allow utilization of different basis functions such as Bézier, Cardinal and B-spline bases. As Computer Aided Manufacturing (CAM) application of the theory, methods are developed for generation of offsets of ruled surfaces useful in Numerical Control (NC) milling and tool motion generation in the Wire Cut Electric Discharge Machining (EDM) operation.
An Approach to Plant Layout Design Based on Constraint-Directed Search
Authors: Akagi Shinsuke , Fujita Kikuo , Nakatogawa Tetsundo , Inoue Motohiro 
Published: April 2021

Abstract
This paper presents an approach to plant layout design based on constraint-directed search. In layout design, the plant has to be arranged to satisfy spatial constraints imposed by the plant components. In our approach, the layout space is divided into finite compartments with a modular size, and the problem is treated as a search problem to assign the facilities to the set of compartments under various constraints. For the classification of the constraints we have implemented a prototype system which introduces a depth-first search algorithm and the concept of layout potential. This has been applied to the design of a nuclear power plant in order to check its validity and effectiveness.
Parametric Computer Aided Hydraulic Cylinder Design: Cylinder Product Modeling
Authors: Johannesson Hans L. 
Published: April 2021

Abstract
In a hydraulic cylinder each cylinder component contributes to the total function, and the components interact and are dependent on each other. The geometry of some components can be completely determined by other surrounding interacting components. In this work it is shown how computer aid can be applied in hydraulic cylinder design when considering component interaction.
A special hydraulic cylinder product model is developed. It is stored in an external CAD system independent data base. The parameters stored in the data base are used when retrieving component data from component family data bases, standard component data bases, and when running parametric component and system design programs.
The software system used in this work consists of an ordinary 2D wire frame modeling turn-key CAD system, FORTRAN application programs, a data base management system, CAD system independent data bases and CAD system dependent interface programs.
Development of a Mechanical Power Transmission Design Supervisor System
Authors: Goulding John R. , Zarefar Hormoz 
Published: April 2021

Abstract
Computer Aided Design and Computer Aided Manufacturing (CAD/CAM) software programs are used in mechanical engineering industries to reduce the time it takes to draft, simulate, machine, and plan a product. When knowledge-based expert rules, equations, and proprietary languages extend CAD/CAM software, previously designed mechanisms can be scaled to satisfy new design requirements in the shortest time.
Two major drawbacks exist in current technology. First, embedded design alternatives needed by design engineers during the product conception and rework stages are lacking. Second, an operator is required who has a thorough understanding of the intended design and the how-to expertise needed to create and optimize the design alternatives.
The focus of our research and development was to automate the intellectual operations; e.g., questioning, identifying, selecting, and coordinating the design process. A robust system emerged which:
1. Selects the best mechanisms necessary to design a power transmission device from proven solutions.
2. Aids the inexperienced operator in developing complex design solutions.
3. Provides design alternatives which add back-to-the-drawing-board capabilities to knowledge-based mechanical power transmission CAD programs.
A Formal Approach to Design Specifications
Authors: Kusiak Andrew , Szczerbicki Edward 
Published: April 2021

Abstract
In this paper a methodology for the specification stage in conceptual design is presented. It allows for problem solving in an active interaction with the designer. An important part of the proposed methodology is the requiremental and functional tree representing the overall logic and structure of the design problem.
The specification stage aims at providing requirements and transforming them into functions of the designed object. It occurs at the highest level of abstraction and it must provide enough information to begin the synthesis process where functions are transformed into design components that are further synthesized into the designed object. The proposed approach was motivated by the following problems: specification of requirements, specification of functions, incorporation of logic into functional and requiremental trees, representation of requirements-functions interaction, and optimization in the functional space.
The methodology presented is illustrated with examples.