bluuebunny/crossref_metadata_2025_split huggingface dataset:
An Algorithm to Slice 3-D Shapes for Reconstruction in Prototyping Systems
Authors: Chalasani K. L. , Grogan B. , Bagchi A. , Jara-Almonte C. C. , Ogale A. A. , Dooley R. L. 
Published: April 2021

Abstract
Rapid Prototyping (RP) processes reduce the time consumed in the manufacture of a prototype by producing parts directly from a CAD representation, without tooling. The StereoLithography Apparatus (SLA), and most other recent RP processes build a 3-D object from 2.5-D layers. Slicing is the process of defining layers to be built by the system. In this paper a framework is proposed for the development of algorithms for the representation and definition of layers for use in the SLA, with a view to determine if the slicing algorithms will affect surface finish in any significant manner. Currently, it is not possible to automatically vary slice thicknesses within the same object, using the existent algorithm. Also, it would be useful to use a dense grid for hatching or skin filling any given layer, or to change the hatch-pattern if desired. In addition, simulation of the layered building process would be helpful, so that the user can prespecify parameters that need to be varied during the process. The proposed framework incorporates these and other features. Two approaches for determining contours on each slice are suggested and their implementation is discussed. In the first, the layers are defined by the intersections of a plane with the surfaces defining the object. The plane is moved up from the base of the object as it is being built in increments. All intersections found are stored in a data structure, and sorted in head to tail fashion to define a contour for all closed areas on a layer. The second approach uses a scanline-type search to look for an intersection that will trigger a contour-tracing procedure. The contour-tracer is invoked whenever an unused edge is found in the search. This saves storage and sorting times, because the contour is determined as a chain of edges, in cyclic order. It is envisaged that results of this work on the SLA can be applied to other RP processes entailing layered building.
Transputer Based Parallel Processing Applied to Machine Vision Inspection
Authors: Carey Richard A. , Daley Wayne D. R. , Lindberg Jon S. 
Published: April 2021

Abstract
The use of Machine vision systems has become more widespread in manufacturing processes for the purposes of quality control inspection, and product identification and sorting. Typical Machine Vision applications need to run in real time (30 frames per second), and as a result most of the existing systems are built from hardware to meet this speed requirement. There is currently no single processor that is reasonably priced and fast enough to provide real time performance on Machine Vision applications. This paper describes a Transputer based system that employs different architectures and algorithms to achieve real time processing speeds for some Machine Vision applications. The paper discusses the differences between sequential and parallel architectures, and the way the unique abilities of the Transputers are utilized to create a flexible system that provides the best performance for a variety of applications. The areas of Machine Vision discussed are Image Acquisition, Image Enhancement, Feature Extraction and Image Interpretation. Image Acquisition and interpretation are discussed briefly, with an in depth discussion of the algorithms and architecture needed to optimize Image Enhancement and Feature Extraction on a Transputer based system.
Computer-Aided Testimg for Compression of Cylinders: A Model for Control of Open-Die Upset Forging
Authors: Ettouney Osama M. 
Published: April 2021

Abstract
A computer-aided testing system for compression of cylinders is developed. The system utilizes force and shape information taken in real-time from the workpiece to calculate process parameters and variables in compression: material properties, foldover, strain, friction, forming-limit diagrams, and fracture. In this way, the system will eliminate the need for other separate tests, such as the ring test used to determine friction. This system is comprised of three functions: a computer-controlled press, models and identification algorithms, and the finite-element analysis. The system is designed to be used as a model for control strategies of the open-die upset forging process. Here, the goal is to control the process so that the final shape is reached without fracture. If fracture is likely to occur at any moment several corrective actions can be taken to allow more deformation, such as modifying lubrication. When tested, the system proved to be accurate in conducting experiments in a well-defined repeatable conditions.
Generation of Offset Curves for NC Machine Tool Path
Authors: Umezaki Eisaku , Watanabe Hiroshi 
Published: April 2021

Abstract
This paper proposes a new method which generates offset curves used to obtain NC machine tool paths. A basic idea of the method is to utilize a called offset curve zone where the offset curves of each side constituting the profile of workpieces are generated. Using this method, we can generate the offset curves without being conscious of unnecessary offset curves often appeared in use of other methods and efficient tool paths because there are almost no overlaps of tool paths. For example, this method is applied to workpiece profiles consisted of the segments of straight line and circular arcs to generate the offset curves for tool paths in a two-and-a-half dimensional pocket cutting.
An Integrated Joint Dynamics System for Elastically Jointed Structures
Authors: Rong Y. , Tzou H. S. 
Published: April 2021

Abstract
The dynamic behavior of elastic joints strongly affect the dynamic performance of a jointed mechanical system. The dynamic contacts introduced by joint clearances create a system with nonlinear characteristics. Special effort needs to be made to study jointed mechanical systems. This paper presents an integrated joint dynamics system, which can be used to predict the dynamic characteristics of a newly designed structure, or to analyze an existing jointed structure. This joint dynamics system can also be applied as a real time monitoring and diagnosis system when it is connected with a vibration measuring device. The joint dynamics system includes: 1) a theoretical model of jointed structures, in which the joint clearance and joint friction effects are considered; 2) a stochastic simulator which is used to generate vibration data and evaluate system dynamic characteristics; 3) a diagnostic monitoring algorithm for vibration state detection; and 4) a forecasting vibration control scheme. The joint dynamics system is applied to the dynamic analysis of a truss-cell unit structure. The results presented in this paper show that the joint dynamics system is effective.
Measuring Nonlinear Dynamic Behavior Using Microcomputers
Authors: Caccese V. , Martin D. 
Published: April 2021

Abstract
This paper details a relatively inexpensive data acquisition/analysis system that was developed at the University of Maine to facilitate the measurement of nonlinear dynamic motion into the chaotic regime. The characteristics of the hardware and specially developed software will be discussed.
The testing system includes a software package, written in TURBO Pascal, that is used to reduce and graphically present the time-history of up to six channels of data simultaneously. The program contains algorithms for digital filtering, smoothing, and Fast Fourier Transforms. The data retrieval software was designed to maximize in-core storage of data and overcomes the current 64 kilobyte memory segment boundary of MS-DOS. Phase Plane projections and Poincaré sections can also retrieved. Analog differentiation and a pulse trigger used to control Poincaré section retrieval are described. A surface of section at any desired phase angle can be taken with this trigger device. A program called POINCARE acquires the signal and its derivative and automatically plots them on the CRT as the test is in progress. A case study of a cantilever beam attracted by two magnets is also presented.
A CAD Program for Optimum Nonlinear Characteristics of a Vehicle Shock Absorber
Authors: Hossamel-deen Yehia H. , Metwalli Sayed M. , Hassan Abdel-hamed S. 
Published: April 2021

Abstract
A Computer Aided Design (CAD) program has been developed in which both simulation and optimization techniques are utilized. A nonlinear representation of the shock absorber damping characteristics has been considered. The output of this CAD program is the optimum shape of this nonlinear characteristics. This is obtained by minimization of a performance index consisting of a weighted sum of the root mean square (rms) of both tire terrain normal force (as a measure of controllability) and the sprung masses acceleration (as a measure of ride comfort). The time response can also be obtained graphically as an output option.
Two different mathematical models are considered: A simple one with two degrees of freedom (Bounce of the sprung and unsprung mass) and a more sophisticated one with four degrees of freedom (Bounce and pitch of the sprung mass and vertical motion of the unsprung rear and front masses). The two models are checked and validated by comparing their results with other published works.
The program results obtained for a typical vehicle show a good improvement of the performance of the optimum nonlinear system compared to the optimum linear one.
PLAN: A Software Package for the Optimization of Planar Four-Bar Linkages
Authors: Tandirci Murat , Angeles Jorge , Liu Zheng 
Published: April 2021

Abstract
This paper introduces a software package called PLAN containing Fortran and C routines to optimize, and visualize planar four-bar linkages for rigid body guidance and path generation. The problem formulation and the design methodology, fully discussed elsewhere, are briefly recalled for quick reference. Examples are included to highlight, the usage of the package, and illustrate the design and analysis stages involved.
SPHERE: A Software Package for the Optimization of Spherical Four-Bar Linkages
Authors: Liu Zheng , Angeles Jorge , Tandirci Murat 
Published: April 2021

Abstract
Introduced in this paper is a software package called SPHERE, meant for the optimization of spherical four-bar linkages for problems of path generation and rigid-body guidance. The optimization methodology is based on an equality-constrained least-squares scheme, as described elsewhere. Considering the similarities of the two problems, we established a more general formulation to cover both synthesis cases. SPHERE is developed based on this formulation. An outline of the methodology and the package is presented in this paper. Two examples are included to illustrate the usage of the package.
SIXPAQ: A Comprehensive Software Package for Analysis and Synthesis of Six-Bar Dwell Linkages
Authors: González-Palacios Max Antonio , Angeles Jorge 
Published: April 2021

Abstract
SIXPAQ is a software package that was created for the interactive analysis and synthesis of six-bar dwell linkages. The package is structured so that any six-bar dwell planar linkage can be designed by simply choosing a reduced number of parameters. Robust algorithms are introduced that allow an accurate and reliable construction of the two loci on which the linkage synthesis procedure is based. Input-output plots and animation are available within the package as visualization aids. The package allows the user to interact with the program to satisfy the dwell and geometry conditions. Animation is achieved using a powerful graphics workstation.
Concurrent Design and Analysis of Mechanisms
Authors: Hollars Michael G. , Rosenthal Dan E. 
Published: April 2021

Abstract
Concurrent design and analysis of mechanisms offer significant improvements in product quality while greatly reducing design cycle time. Recent advances in CAE software now give very powerful analysis and design capability directly to the design engineer. The key advances are intuitive graphical interfaces, adapation of analysis software to the design process, and seamless integration with existing CAD/CAM/CAE products. Several examples of concurrent mechanism design and analysis are given along with an overview of CAE mechanism design and analysis software, including Applied Motion® from Rasna Corporation.
IGES Success on a Shoestring: A Management Case Study of CAD/CAM Data Exchange
Authors: Stokes Harlan 
Published: April 2021

Abstract
In the Autumn of 1988, the Materials Operations at Control Data Corporation’s Computer Products Group began a program to electronically exchange mechanical CAD models with its suppliers. The “Supplier CAD-Link” program provided many immediate benefits and offers a unique learning experience about electronic data interchange. Existing technologies are used, so the program operates on a shoestring budget with no major dollar investments required of CDC or the suppliers. The program uses the IGES standard file format, so suppliers can apply the lessons learned to CAD/CAM data exchanges with other companies. Now, with the continuing success of the CAD-Link program. Computer Products is re-evaluating many of the old paper based methods of doing business. This paper explores some of the issues for managing a CAD/GAM data exchange program.
A Framework for Feature Based Part Modeling
Authors: Chen Yuh-Min , Miller R. Allen , Vemuri K. Rao 
Published: April 2021

Abstract
To increase the capabilities and intelligence of CAD/CAM systems, a feature based modeling environment, integrated with a knowledge based environment, is under development utilizing a commercial CAD system. This environment allows designers to model parts with features, and provides high-level part models to support geometric reasoning in manufacturing assessment and related functions. Two fundamental issues have been considered: (1) What kind of information is required to specify a part and to support reasoning about the part in a wide variety of applications?, and (2) How can the results serve the geometric reasoning needs of the various engineering applications which need geometric information about the part? This paper will discuss the information required for defining net shaped parts (parts to be manufactured by net shape processes), a framework for a feature based modeling environment, the procedures for feature based design, and the construction of high-level (semantic) pan models suitable for geometric reasoning in a knowledge based environment.
A Computer Modeling of the Czochralski Growth of Bismuth Silicon Oxide With Free Surface
Authors: Liaw G. S. , Zheng Y. M. , Mo J. D. , Chou L. C. 
Published: April 2021

Abstract
A comprehensive numerical modeling of the Czochralski crystal growth system has been conducted for the growth of Bismuth Silicon Oxide (BSO). Both the thermal buoyancy and the surface tension effects are taken into account in the convective flow field. A pressure-based numerical algorithm in conjunction with an algebraic adaptive grid procedure is employed for the simultaneous solution of the melt flow field and the global melt/solid temperature distribution. The free surface effect is treated by coupling the Young-Laplace equation with the flow field along the interface. The results of the quasi-steady-state model at three different stages are presented, they agree with the experimental observations qualitatively.
A Methodology to Handle Inequality Constraints in an Interactve Design Process
Authors: Sridhar Natarajan , Agrawal Rajiv , Kinzel Gary L. 
Published: April 2021

Abstract
The treatment of mechanical design as a constraint management problem has long been related to equality constraints. Work involving inequality constraints has been generally restricted to optimization and symbolic computation. This paper presents a methodology for handling inequality constraints in an interactive mechanical design process. The presented method is similar to the basis interchange algorithm used in the Generalized Reduced Gradient (GRG) method for constrained nonlinear optimization. The main difference is that our method relies on user guidance to select which specification has to be changed in order to satisfy the violated inequality constraint. Also, the specification is only adjusted; unlike the procedure in the GRG method where the basis is changed. An inequality constraint violation is detected whenever the corresponding slack variable becomes negative. An occurrence-matrix formulation is used to represent both the equality and inequality constraints that govern the design. The work is illustrated for the classical weldment design problem.
New Approach to the Design of Multitechnology Systems
Authors: Viitanen Pasi , Yli-Paunu Pekka , Yli-Pietilä Timo , Suoranta Risto 
Published: April 2021

Abstract
We introduce a design environment for complex multitechnology systems. The design environment supports hierarchical, multi-level and mixed-mode simulation. The design environment is based on commercially available CAE-tools including graphical interfaces for both mechanical and analog simulators. The system is built around the high-level hardware description language and interactive postprocessor tools for simulators. Linear and non-linear systems can be modelled in time and frequency domains. There is a simulation example of multitechnology system including, electronical, hydraulical and mechanical components.
On Implementing an Integrated Design-Manufacturability Assessment Environment
Authors: Chen Yuh-Min , Miller R. Allen , Vemuri K. Rao 
Published: April 2021

Abstract
Due to the incomplete representation schemes and the lack of high-level reasoning capability of current CAD/CAM systems, manufacturability assessment is performed by experienced designers and manufacturing engineers. The problems associated with automating manufacturing assessment include (1) the integration of a knowledge based environment within a design environment to provide reasoning capability, and (2) the development of flexible, modularized and responsive part models with levels of abstraction to support high-level reasoning which is required. Since modification of part geometries are frequently made during manufacturability assessment, the capability for part geometry modification is required at the level of interacting procedures. Consistency problems therefore occur between the geometric database in design environment and the part model in knowledge based environment. This paper presents a framework for an integrated design and manufacturability assessment environment which address these concerns.
Computer Aided Design of Support Structures for Stereolithographic Components
Authors: Kirschman C. F. , Jara-Almonte C. C. , Bagchi A. , Dooley R. L. , Ogale A. A. 
Published: April 2021

Abstract
Stereolithography is a process used to rapidly produce polymer components directly from a computer representation of the part. Support structures, required for all parts built this way, are used to support a component during the build but are removed once building is complete. They anchor the component to the platform and prevent distortion, and are designed simultaneously with the component.
A software package to aid the designer is under development at Clemson University. The Clemson Intelligent Design Environment for Stereolithography (CIDES) serves as an interface between the CAD systems and the SLA, cornbining utilities and research efforts. One aspect of this is the automatic support generation algorithm, which designs support structures using knowledge gained from experimentation and experts.
The algorithm uses a stereolithographic format representation of a part and gives the user several design options. It then produces both base and projection supports. Output is in slice-ready form.
Optimal Design of Structural Components Fabricated With Composite Materials
Authors: She Kun , Sadler J. P. , Tauchert T. R. 
Published: April 2021

Abstract
The static and dynamic optimal design of structural components fabricated with advanced composite materials are studied by combining the finite element method and optimization techniques. Different element types, loads, component structures and objective functions are investigated. Beams and torsion members are analyzed using the ANSYS finite element program and are optimized via an interface to an optimization software package. The particular element types used to model the composite components include beam elements with equivalent overall material properties and layered shell elements. The optimization variables include member cross sectional dimensions and composite lamina thicknesses and fiber orientations. The optimal results show significant improvement in deflection amplitude levels and dynamic settling times relative to conventional metals and nonoptimized composite materials.
DAMP: A General Purpose Optimization Program for Modeling, Analysis, and Synthesis of Mechanisms
Authors: Krishnamurty Sundar , Turcic David A. 
Published: April 2021

Abstract
This paper presents the description of an integrated software package titled DAMP (Design and Analysis of Mechanisms Program) that has been developed for the purposes of modeling, analysis, and synthesis of planar linkage mechanisms. DAMP is a comprehensive computer-aided design tool with the ability to design complex planar mechanisms including higher order mechanisms with multiple loops and multiple degrees of freedom. It is also capable of addressing a wide range of design objectives such as the position, velocity, acceleration, and force requirements. DAMP employs matrix methods for the modeling and analysis of mechanisms, and the method of nonlinear goal programming in the determination of the optimal mechanism solutions. Two mechanism design examples are presented to illustrate the various capabilities of this software package.
Geometric Modeling and Visualization of Manipulator Workplace
Authors: Chen X. , Gupta K. C. 
Published: April 2021

Abstract
This paper introduces a new and powerful technique to determine the workspace shape of a general n-joint manipulator by utilizing geometric modeling. A complete three-dimensional geometric model of the workspace shape can be generated which is compatible with the computer graphics. The resulting workspace image can be visualized in three-dimensions realistically, manipulated interactively and analyzed for topological and volumetric features. The first part of the paper presents a general discussion of the workspace geometry and boundary representation concept. The remainder of the paper focuses on two workspace boundary extraction methods in a CAD environment: Radial-Slice-Layering method (RSL) and Apparent-Contour method (AC). Several specific examples are presented to illustrate the basic technique.
A Constrained Optimization Approach to Finite Element Mesh Smoothing
Authors: Parthasarathy V. N. , Kodiyalam Srinivas 
Published: April 2021

Abstract
The quality of a finite element solution has been shown to be affected by the quality of the underlying mesh. A poor mesh may lead to unstable and lor inaccurate finite element approximations. Mesh quality is often characterized by the “smoothness” or “shape” of the elements (triangles in 2-D or tetrahedra in 3-D). Most automatic mesh generators produce an initial mesh where the aspect ratio of the elements are unacceptably high. In this paper, a new approach to produce acceptable quality meshes from an initial mesh is presented. Given an initial mesh (nodal coordinates and element connectivity), a “smooth” final mesh is obtained by solving a constrained optimization problem. The variables for the iterative optimization procedure are the nodal coordinates (excluding, the boundary nodes) of the finite element mesh, and appropriate bounds are imposed on these to prevent an unacceptable finite element mesh. Examples are given of the application of the above method for 2/3-D triangular meshes generated using a QUADTREE | OCTREE automatic mesh generators. Results indicate that the new method not only yields better quality elements when compared with the traditional Laplacian smoothing, but also guarantees a valid mesh unlike the Laplacian method.