bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Curved Surfaces Using the Parametric B-Spline Tensor Product
Authors: Tsay D. M. , Chen C. M. 
Published: April 2021

Abstract
A general, computational geometry design procedure for the synthesis of curved surfaces is presented. The method applies the parametric B-spline (basis spline) tensor product to interpolate prescribed geometrical constraints, even when the set of constraints is sizable. Using the well-developed mathematical tool, B-spline functions, the method is very dependable, versatile, and numerically stable for the design of mechanical parts with complex shapes. Since a curved surface can be represented by a formula of B-spline tensor product, the approach enables the coordinates required for analysis or manufacturing to be easily generated. Typical examples for the synthesis of curved surfaces are given to illustrate the application of the approach.
Computer Aided Geometric Design of Motion Interpolants
Authors: Ge Q. J. , Ravani B. 
Published: April 2021

Abstract
This paper studies continuous computational geometry of motions and develops a method for Computer Aided Geometric Design (CAGD) of motion interpolants. The approach uses a mapping of spatial kinematics to convert the problem of interpolating displacements to point interpolation in the space of the mapping. To facilitate the point interpolation, the previously non-oriented mapping space is made orientable. Methods are then developed for designing spline curves in the mapping space with tangent, curvature and torsion continuities. The results have application in computer animation of three dimensional objects used in computer graphics, computer vision and simulation of mechanical systems.
Rational Polynomial Surface Intersections
Authors: Kriezis G. A. , Patrikalakis N. M. 
Published: April 2021

Abstract
This paper presents a new algorithm for the computation of the intersection of two rational B-spline surface patches. This algorithm is based on the computation of significant points of the intersection in the parameter space of one of the patches using direct numerical techniques; partitioning of the intersection domain at these points; tracing of the resulting intersection segments using subdivision and Newton or marching techniques; and verification of computation of all intersection branches using convexity properties of the two surfaces and their partial derivatives.
Synthesis and Analysis of Geometric Design Models Using Tree-Structured Relations
Authors: Tsai P. L. , Chieng Wei-Hua , Hoeltzel David A. 
Published: April 2021

Abstract
A methodology for the synthesis and analysis of a relational geometric design model, based on a mapping between geometric nodes (points) on the object which are stored in a tree structure and physical dimensions, is presented in this paper. For this methodology, the relations between geometric nodes are restricted to both translation and rotation. An algorithm has been implemented based on this methodology that allows a designer to freely synthesize and analyze geometric relations among key physical dimensions of the object, while the management of the underlying parameterized relational geometric data occurs automatically.
A Fast Wireframe Display Algorithm for Hidden Surface Removal in Constructive Solid Geometry
Authors: Jeng Shyr-Long , Chieng Wei-Hua , Hoeltzel David A. 
Published: April 2021

Abstract
A fast algorithm for rendering three dimensional geometry as wireframes is developed. The algorithm employs a constructive solid geometry (CSG) model as its underlying geometric representation scheme, set membership classification for the removal of non-boundary lines, and a finite-point backward ray tracing method for hidden line removal. By eliminating conventional polygon surface approximation and its associated surface topology representation, requiring high information overhead, the algorithm demonstrates speed and simplicity. The primary purpose of the algorithm is for expeditious real-time graphical simulation, particularly for interactive design. The algorithm demonstrates overall time complexity of O(n2 h*2), where n denotes the total number of geometric primitives, and h* denotes the total number of boundary edge segments. Desirable side effects associated with the use of set membership classification include the ability to generate NC machine instructions and the detection of object interference for collision avoidance during the simulation of manufacturing processes. Examples demonstrating the visualization of 3-D mechanical components are included.
The Shortest Path for a Point Passing Through Obstacles Represented by Quadratic Curves
Authors: Blechschmidt James L. , Wu J. L. 
Published: April 2021

Abstract
In this paper we present an algorithm for the search of the shortest path through a set of obstacles approximated by circles and ellipses. A set of heuristics is developed to eliminate obstacles that do not affect the search for the shortest path. The A algorithm is used during the path generation phase to direct work toward the estimated shortest path. Algebraic techniques are used for computing a set of pseudo vertices since no natural vertices exist with the algebraic representation of the obstacles. Examples are given to demonstrate the techniques developed.
Synthesis and Steady State Analysis of High-Speed Elastic Cam-Follower Linkages With Concentrated Masses: Part I — Theory
Authors: Liu Hsin-Ting J. , Flugrad Donald R. 
Published: April 2021

Abstract
A cam driving a lumped inertia through a massless, elastic, slider-crank follower linkage with two concent rated masses located at the pin joints is considered. An iterative procedure taking the elasticity, damping, and changing geometry of the linkage into account is developed for synthesizing the cam profile to produce a desired output motion at a given design speed. The steady state solutions for the inhomogeneous, periodic, linear, ordinary differential equations are solved numerically by Hsu’s method.
Synthesis and Steady State Analysis of High-Speed Elastic Cam-Follower Linkages With Concentrated Masses: Part II — Steady State Analysis
Authors: Liu Hsin-Ting J. , Flugrad Donald R. 
Published: April 2021

Abstract
The responses for different design and simulation conditions, including various speed and damping ratios, are investigated for an elastic cam-follower system discussed in Part I. The location of a single dominant pair of characteristic multipliers of the inhomogeneous periodic linear system is found to have significant influence on the steady state response.
The Incorporation of Arc Boundaries and Stick/Slip Friction in a Rule-Based Simulation Algorithm for Dynamic Mechanical Systems With Changing Topologies
Authors: Han Inhwan , Gilmore Brian J. , Ogot Mandara M. 
Published: April 2021

Abstract
Many dynamic mechanical systems, such as parts-feeders and percussive power tools, are described by equations of motion which are discontinuous. The discontinuities result from kinematic constraint changes which are difficult to foresee, especially in presence of impact and friction. A simulation algorithm for these types of systems must be able to algorithmically predict and detect the kinematic constraint changes without any prior knowledge of the system’s motion. This paper presents a rule-based approach to the prediction and detection of kinematic constraint changes between bodies with arc and line boundaries. A new type of constraint change, constraint exchange, is characterized. When arc contact exist, stick/slip friction is the difference between pure rolling and rolling with slip. Therefore, stick/slip friction is included in the algorithm. A force constraint is applied to the equations of motion when additional kinematic constraints due to friction would render the coefficient matrix singular. The efficacy of the rule-based simulation algorithm as a design tool is demonstrated through the design and experimental validation of a parts-feeder. The parts-feeder design is validated through two means; 1). a frame-by frame comparison of simulation results with the part motion recorded by high speed video and 2). actual testing.
The Formulation of Kinematic Constraints in Design-Oriented Machine Dynamics
Authors: Saha Subir Kumar , Angeles Jorge 
Published: April 2021

Abstract
In the realm of the dynamic analysis of machinery for design purposes, the determination of non-working constraint forces, which do not appear in simulation studies, is of the utmost importance. The said forces can be readily computed if suitable kinematic constraints are available. In this paper, a formulation of kinematic constraints is adopted, that pertains to the natural orthogonal complement method, introduced elsewhere, for the dynamic modeling of mechanical systems. This formulation is illustrated with several examples.
Synthesis and Steady State Analysis of High-Speed Elastic Cam Follower Linkages by a Finite Element Method
Authors: Liu Hsin-Ting J. , Flugrad Donald R. 
Published: April 2021

Abstract
A cam driving a lumped inertia through an elastic slider-crank follower linkage with a curved beam coupler is considered. An iterative procedure utilizing the finite element method developed by Midha et al. (1978) is used to synthesize the cam profile to produce a desired output motion at a given design speed and damping coefficient. Nonlinear terms are neglected producing inhomogeneous. periodic, linear, ordinary differential equations. Response of the synthesized linkages are simulated and found to be satisfactory at the design conditions.
Computational Geometry for Optimal Workpiece Orientation
Authors: Haghpassand Khorssand , Oliver James 
Published: April 2021

Abstract
Workpiece orientation is formulated as an optimal design problem based on a discrete approximation of design surface geometry and the kinematic capabilities of the process machine tool. The primary process application addressed is three- and four-axis numerically controlled (NC) milling, although the techniques presented may be applied to machines with more general articulation. Recent developments in applied spherical geometry are employed to formulate a nonlinear optimization problem. For three-axis milling applications, by assigning a weight to each surface normal of the discrete model corresponding to the actual area it represents, the orientation is optimized such that the angle between the normals and the milling tool axis is minimized. This formulation is augmented, for four-axis milling, to incorporate limitations of the rotational degree of freedom into the optimization formulation.
Pseudoedge: A Hierarchical Skeletal Modeler for the Design of Structural Components
Authors: Bonner David L. , Jakiela Mark J. , Watanabe Masaki 
Published: April 2021

Abstract
A new design model for the creation of mechanical components has been developed. In this model, the shape is expressed by its areas of prominence or maximum curvature, for which we use the term pseudoedges. In terms of traditional design, these represent both fillet, chamfer and intersection lines, and more general shape features. The pseudoedges of the model combine with a skeletal shape that is used as a starting form, thereby creating a hierarchy of geometric dependencies that affords both global and local control. The surface is represented by a quilt of parametric Bezier patches, with tangent plane continuity everywhere and only certain isolated singularities. Considerable degrees of deformation are possible, with predictable control and at small computational expense; there is no need for computation of intersections or parameter space trimming of patches.
Motion Planning in Plant CAD Systems
Authors: Kondo Koichi , Ohtomi Koichi 
Published: April 2021

Abstract
This paper discusses a general and efficient method for solving the motion planning problem defined as checking the existence of a collision-free path among known stationary obstacles, and also presents its application to a plant CAD system. The basic approach taken in this method is to restrict the free space referred to in path searching and to avoid executing unnecessary collision detections. The configuration space is equally quantized into cells by placing a regular grid, and two new search strategies which enumerate restricted cells are introduced for realizing this method. One is a local strategy which enumerates free space cells only along the boundary of the free space in the configuration space. Another is a global strategy which finds the outer boundary of the free space. This method has been actually implemented and has been applied to an example in a nuclear power plant.
Automated Linearization of Nonlinear Coupled Differential and Algebraic Equations
Authors: Vanderploeg Martin J. , Trom Jeff D. 
Published: April 2021

Abstract
This paper presents a new approach for linearization of large multi-body dynamic systems. The approach uses an analytical differentiation of terms evaluated in a numerical equation formulation. This technique is more efficient than finite difference and eliminates the need to determine finite difference pertubation values. Because the method is based on a relative coordinate formalism, linearizations can be obtained for equilibrium configurations with non-zero Cartesian accelerations. Examples illustrate the accuracy and efficiency of the algorithm, and its ability to compute linearizations for large-scale systems that were previously impossible.
Generating the Swept Area of a Body Undergoing Planar Motion
Authors: Ling Zhi-Kui , Chase Thomas R. 
Published: April 2021

Abstract
The swept area of a two dimensional object undergoing motion in its plane of definition is the union of the area occupied by the object at all positions during the motion. A methodology for determining a close approximation to an exact swept area for a known arbitrary motion is developed here. The methodology has use for preventing interference between links of a planar mechanism during synthesis.
Criteria for determining individual points falling on the border of the swept area from the body during any instant of the motion are derived from envelope theory. Points on the swept area boundary are determined at the initial position of the sweeping body for computational efficiency. The swept area is constructed from these points plus sections of the border of the moving body at select positions. Overlap of the swept area onto itself is handled by splitting the overall swept area into a small number of individual swept areas free of overlap. An eleven-step swept area algorithm is clarified with an example.
Automatic Surface Generation From Wireframe Data Enhancements
Authors: Parameswaran Ramesh , White Phillip R. 
Published: April 2021

Abstract
This paper presents several enhancements to existing methods of converting wireframe CAD models to surface representations. Existing methods consider only polyhedral objects. In these methods, closed loops of edges in the wireframe, which define the boundaries of planar surfaces, are first detected by a combination of topological and geometric techniques. The regions bounded within these edges are then approximated by a number of planar polygons. Enhancements described in this paper permit the algorithms to be extended to wireframes that describe objects with curved surfaces and surfaces with holes. An approach for tesselating curved surfaces is also described. With these enhancements, conversion methods can then be applied to arbitrary wireframes without imposing restrictions on the edges or surfaces that comprise the wireframes.
Analysis of Axisymmetric Piezoceramic Microactuators and Designs for Fluid Control Applications
Authors: Kosaraju Chenchiah B. , Naganathan Nagi G. 
Published: April 2021

Abstract
A finite element model has been developed to analyze axisymmetric piezoceramic actuators with arbitrary internal poling. The finite element methodology is verified by demonstrating a favorable agreement of the numerical results obtained in this study with results published for an ink-jet printer application. In addition, design of a piezoceramic nozzle is investigated with both single layer and stacked axisymmetric piezoceramic geometries. Such piezoceramic micronozzles can be effectively employed in sensitive low-displacement valve applications such as speed control of jet engines.
Cam Motion Synthesis Using Cubic Splines
Authors: Yoon Kooyoung , Rao S. S. 
Published: April 2021

Abstract
The application of minimum norm principle, similar to the principle of minimum potential energy, is presented for the general synthesis of cam motion. The approach involves the use of piecewise cubic spline functions for representing the follower displacement. The cubic splines are more convenient and simpler to use compared to general spline functions and also result in smaller peak acceleration and jerk due to the application of the minimum norm principle. A general procedure is presented for application to any cam-follower system. The effectiveness of the approach is illustrated by comparing the results given by the present method with those given by other approaches for a disk cam-translating follower.
Numerical Analysis of the Kinematic Dexterity of Mechanisms
Authors: Yang Feng-Cheng , Haug Edward J. 
Published: April 2021

Abstract
A broadly applicable approach for numerical analysis of kinematic working capability of mechanisms is presented. Composite workspaces are introduced to represent position and orientation capabilities of mechanisms, both individually and together. Numerical methods for solving systems of kinematic constraint equations, using a moving-frame algorithm, and equations that characterize the workspace boundary are developed. Two analytic methodologies, comparison and incorporation methods, are presented to determine whether the workspace of a mechanism satisfies design requirements. A computer program for workspace analysis that incorporates a numerical solver and computer graphics for visualization on a high speed graphics workstation is outlined. The feasible positioning space of a Stewart platform that is subject to orientation constraints is computed, to illustrate the use of this approach and the associated computer program.
An Automated Procedure for the Maximization of the Mechanical Advantage of Planar Mechanisms
Authors: Ogot Madara M. , Gilmore Brian J. 
Published: April 2021

Abstract
This paper presents an automated procedure for the maximization of the mechanical advantage (M) of planar mechanisms. First, the classical definition of mechanical advantage is extended to include multiple-input, multiple-output mechanisms, thus allowing the maximization of the mechanical advantage of multiple-input mechanisms, a task which was hitherto not possible. A knowledge-based approach is utilized to perform a sensitivity analysis from which the mechanism parameters are automatically altered. In this manner the human designer is removed from the optimization loop. Several examples are presented which illustrate the versatility and generality of this approach.
Dynamic Modeling of Planar Closed-Loop Kinematic Chains Based on an Instantaneously Unconstrained Energy Equivalence Scheme
Authors: Lai Chieng-Liang , Chieng Wei-Hua , Hoeltzel David A. 
Published: April 2021

Abstract
Traditional Euler-Lagrange methods for the dynamic analysis of kinematic chains require repetitive calculation of the kinematic constraints. This becomes very inefficient as the number of joints (or kinematic constraints) increases. This paper presents a new approach for the dynamic analysis of constrained dynamic systems. The salient feature of this approach is the separation of the kinematic analysis from the dynamic analysis. Following this separation, the resulting dynamic system becomes instantaneously unconstrained. While the discussion is mainly oriented towards the analysis of planar mechanisms, the model can be readily extended to the analysis of spatial mechanisms. A methodology for computer-aided symbolic derivation of the dynamic equations based on this approach is presented, and a numerical example which demonstrates a significant reduction in computing time for the dynamic analysis of a planar mechanism, as compared with conventional solution approaches, is provided.
Computer Aided Part Design Based on Standard Component Interface Geometry
Authors: Johannesson H. L. 
Published: April 2021

Abstract
In this paper it is suggested how an integrated computer based system for part design can be built. The main issue is how to automatically provide geometry data, determined by selected interacting standard components, to the used CAD-system. This kind of function determined geometry is in the paper called “interface geometry.”
The key component in the integrated computer program system is the standard component data base. This data base contains a parametric model of the standard component and its “interface geometry”. Parameters necessary as input data both to component performance analysis programs and geometry creation programs, are all included in the model.
The integrated program system consists of a data base, managed by a data base management system, application programs for component performance analysis and selection, and a conventional CAD-system. In order to make these different parts communicate, certain interface programs, both CAD-system dependent and independent, have been developed.
Integrated Optimization in Computer-Aided Design and Manufacturing of Machine Products Based on Shape Descriptions of Contact Surfaces
Authors: Yoshimura Masataka , Takeuchi Atsushi 
Published: April 2021

Abstract
This paper proposes a method for integrating CAD and CAM in which both maximization of the product performance and minimization of the product manufacturing cost are sought. In order to obtain effectively and efficiently the optimum decision variables for the integrated product design and process design, a method for describing machine-parts shapes is first developed with main consideration being given to the description of the contact surfaces. Then, a multiphase decision making method using those data is constructed in which the decision making process is divided into three phases. The shapes, materials, and manufacturing methods of machine parts are then determined in steps according to multi-phase processes. Finally, the proposed methods are applied to the design of an industrial robot for demonstrating the effectiveness of the methods.
Sequential vs. Concurrent Formulations for the Synthesis of Engineering Designs
Authors: Karandikar H. M. , Rao J. , Mistree F. 
Published: April 2021

Abstract
Modeling and gaining an understanding of the interaction between information from design and from manufacturing is an important step in developing techniques and methods for concurrent engineering. In this paper, the role of optimization techniques in the product development process in a concurrent engineering framework is examined. Through arguments based in optimization theory, it is demonstrated that a concurrent approach to designing for manufacture problems is superior to a sequential one. By extension, this applies to designing for other life-cycle processes. Results which illustrate the point are presented from a comprehensive, non-textbook case study in design using composite materials and dealing with the integration of analysis, dimensional synthesis, and manufacturing. The case study is tackled by using Decision Support Problems. The focus in the paper is on understanding the ramifications of considering life-cycle processes concurrently.