bluuebunny/crossref_metadata_2025_split huggingface dataset:
Implicit Integration of the Equations of Multibody Dynamics in Descriptor Form
Authors: Haug Edward J. , Iancu Mirela , Negrut Dan 
Published: February 2021

Abstract
An implicit numerical integration approach, based on generalized coordinate partitioning of the descriptor form of the differential-algebraic equations of motion of multibody dynamics, is presented. This approach is illustrated for simulation of stiff mechanical systems using the well known Newmark integration method from structural dynamics. Second order Newmark integration formulas are used to define independent generalized coordinates and their first time derivative as functions of independent accelerations. The latter are determined as the solution of discretized equations obtained using the descriptor form of the equations of motion. Dependent variables in the formulation, including Lagrange multipliers, are determined to satisfy all the kinematic and kinetic equations of multibody dynamics. The approach is illustrated by solving the constrained equations of motion for mechanical systems that exhibit stiff behavior. Results show that the approach is robust and has the capability to integrate differential-algebraic equations of motion for stiff multibody dynamic systems.
AutoCam: A Modular Decision Support System for the Design of Cam Mechanisms
Authors: Shooter Steven B. , Reinholtz Charles F. 
Published: February 2021

Abstract
Good engineering practice requires designers to incorporate knowledge, processes and skills to produce a superior product. Each stage of the product realization process requires that the designer utilize available resources to make sound engineering decisions in a timely manner. Much of the research on engineering design has focused on formulating general models for the design process. However, it has been shown that these models are rarely used by engineers in practice. This paper advances the concept that useful design models and the resulting support systems must include methodologies that are particular to a given field or type of design in an overall design methodology framework. The inclusion of these knowledge-domain-dependent methodologies provides a complete framework for the greatest utility to the designer. The paper then describes a decision support system, AutoCam, that embodies these principles for assisting designers in the process of synthesizing cam mechanisms. AutoCam is a comprehensive, modular computer tool that is integrated with a PC-based CAD package to assist the designer throughout the design process, from the problem confrontation, through the formulation of objectives and establishing specifications, and synthesizing the resulting cam profile. While several software programs are available for synthesizing a cam profile from a given motion program, no other current package assists the designer with the complete process of cam mechanism design. AutoCam provides a design model that incorporates a detailed methodology with background information and analytical tools for design.
A System Level Approach to the Design of an Industrial Ecosystem
Authors: Bailey Reid , Allen Janet K. , Bras Bert , Mistree Farrokh 
Published: February 2021

Abstract
Industrial ecology is a nascent concept in which systems of industries work together to reduce their net negative environmental impact. The work in this paper represents an initial step towards the advancement of industrial ecology through quantitative analysis. A system dynamics model of an existing industrial ecosystem is developed in STELLA® and used to represent the system level behavior. A design tool, the Robust Concept Exploration Method (RCEM), that has been used previously for more traditional design problems, e.g., engine design and airplane design, is successfully applied to the system level design of an industrial ecosystem. The results in this paper are intended to provide support for decision makers in complex industrial ecosystems and, more importantly, to increase the knowledge about designing industrial ecosystems. As the concept of industrial ecology progresses, the analysis of ecosystems will become more complex, increasing the need for design at the system level to be addressed with tools such as the RCEM.
Geometric Abstractions to Support Contact Based Disassembly Evaluation
Authors: Shyamsundar N. , Gadh Rajit 
Published: February 2021

Abstract
Determining whether an assembly can be constructed from its components at the design stage results in reduction of assembly problems downstream. One approach to determine if an assembly can be constructed is to perform a disassembly evaluation of the assembly’s geometric model. Abstractions derived from the geometric model may be used to evaluate the disassembly sequence. This paper presents two abstractions to support the disassembly analysis: 1) the Assembly Topology Graph (ATG), and 2) the set of boundary components.
The first abstraction, the ATG, is a graph whose nodes represent the components in the assembly, and whose edges represent a non-null intersection of the convex hulls of component pairs. The second abstraction, the set of boundary components, represents the set of components that intersect the boundary of the assembly which is the convex hull of the assembly. The use of the abstractions in determining the validity of the assembly is discussed in the paper.
Improving the Efficiency of Simulated Annealing Optimization Through Detection of Productive Search
Authors: Szykman Simon , Schmidt Linda C. , Shetty Harshawardhan 
Published: February 2021

Abstract
The popularity of simulated annealing for engineering design applications has grown in recent years, increasing the need for new techniques that improve algorithm performance. Simulated annealing is a time-consuming, iteration-intensive algorithm. One area of algorithm enhancement with high potential impact is the development of methods for improving the algorithm by reducing the amount of wasted or non-productive search. This paper presents an approach to detection of productive search based on statistical process control (SPC) concepts. The proposed Detection of Productive Search (DPS) annealing schedule is compared to three other viable schedules using a 100-city traveling salesman problem. The DPS schedule produces results on par with the best from the more traditional schedules but does so with significantly fewer iterations.
Weight Optimization of Transmission Towers
Authors: Jonsson Magnus Thor , Gudmundsson Ketill H. 
Published: February 2021

Abstract
This paper presents a new approach to the minimum weight optimization of transmission towers, which consists of formulating the optimization problem in a net weight objective function with no constraints. Genetic algorithms are employed to perform the optimization. Instead of using the well known penalty function method to account for design constraints, the constraints are integrated in to the objective function. By selecting cross-sections inside the objective function ensures that the structure, being optimized, is always in full compliance with standard codes of practice for strength assessment of transmission towers.
The paper is primarily concerned with practical aspects of transmission tower design and the method is presented with examples based on accepted codes of practice and realistic tower designs. The problem is formulated for a full size transmission tower, where selected portions of tower topology and geometry are optimized, including a cross-sectional optimization from a set of commercially available steel sections.
Edges of Regression and Limit Normal Point of Conjugate Surfaces
Authors: Chen Ningxin 
Published: February 2021

Abstract
The present paper utilizes the basic theory of the envelope surface in differential geometry to investigate the undercutting line and the contact boundary line on the conjugate surfaces. It is proved that the edges of regression of the envelope surfaces are the undercutting line and the contact boundary line in theory of gearing respectively. Two groups of equations for the undercutting and the contact boundary lines of the conjugate surfaces are developed based on the definition of the edges of regression in differential geometry. The geometric meaning of Wildhaber’s concept of the limit normal point is explained. Numerical examples are taken for illustration of the above-mentioned concepts and equations.
Determination and Analysis of Pinion Mismatch for Hypoid Drives
Authors: Zhang Yi , Wu Zhi , Li Nai-Yi 
Published: February 2021

Abstract
This paper presents an approach for the determination of conjugate pinion tooth surfaces of hypoid drives and the analysis of pinion mismatch. The conjugate pinion tooth surface is compared with the tooth surface of the pinion manufactured by the machine tool settings obtained by the local contact synthesis. The analysis of the mismatch provides a quantitative verification of the pinion surface modifications and complements the existing tooth contact analysis. A numerical example is included in the paper to demonstrate the analysis of pinion mismatch and tooth contact.
Dynamics Modeling of Elastic Multibody Systems Using Kane’s Method As Applied to a Flexible Robot
Authors: Meghdari Ali , Fahimi Farbod 
Published: February 2021

Abstract
Generalization of Kane’s equations of motion for elastic multibody systems is considered. Initially, finite element techniques are used to generate the elastic form of generalized coordinates. Then, the number of elastic coordinates are reduced by the component mode synthesis. Finally, Kane’s method is applied to obtain the equations of motion of such systems. Using this method, dynamic model of an elastic robot with one degree of freedom is presented.
KADS2: A Next Generation Knowledge Aided Design System
Authors: McVea William M. , Haghighi Kamyar 
Published: February 2021

Abstract
Research has been conducted in the areas of design methodology, automation and use of knowledge based systems as a tool to improve the design efficiency, accuracy and consistency for mechanical power transmissions. The research capitalized on previous work related to component level design synthesis and analysis. The next logical step in the research progression was to look into system development and integration of design synthesis and analysis tools. Deliverables from this research include new knowledge acquisition techniques, a more complete model of design information flow and development and a knowledge based design assistant system, capable of integrating multiple discrete and disparate design tools.
A Feature Free Approach to 5-Axis Tool Path Generation
Authors: Laxmiprasad Putta , Sarma Sanjay 
Published: February 2021

Abstract
In recent years, CAD/CAM integration for machining has been based on the concept of manufacturing features. In this paper we present an overview of an alternative scheme to integrate CAD with CAM. Instead of decomposing the design into manufacturing features, we generate tool paths directly from the shape of the workpiece using visibility and accessibility arguments. This approach builds on the work of a number of previous efforts to bring concepts from robotic path planning into the realm of NC planning. We present a hardware approach for computing visibility rapidly. This information is then used to determine the “principal directions”, or setups, around which the search will be conducted to remove material from the workpiece. The machining is conducted in two stages. The first stage, global roughing, is performed for each principal direction. The bulk of the material is removed through 5-axis roughing tool paths. Algorithms have been developed to generate these tool paths in an efficient way. The removal volume is first stratified into “4−1/2D machining pockets”, for which tool paths are generated with simple “space filling 2D curves based on the Voronoi Diagram. After global roughing, the surface of the part can be finished with “face based finishing.” In this step, each face is independently machined to the required finish and accuracy using a face-oriented, rather than feature-oriented, approach. The primary concern is to meet accessibility constraints for each face while generating tool paths individually. Once toolpaths have been generated, we simulate them and correct residual intersection problems before outputting final NC code. Since this is an overview paper that attempts to summarize current and future research in an ongoing project, we concentrate on some key issues such as accessibility, while only summarizing other individual ideas briefly. We also present some experimental results through illustrations.
Toward Hybrid Variant/Generative Process Planning
Authors: Elinson Alexei , Herrmann Jeffrey W. , Minis Ioannis E. , Nau Dana S. , Singh Gurdip 
Published: February 2021

Abstract
This paper describes our ongoing work on a hybrid approach to process planning, that attempts to combine the best characteristics of both variant and generative process planning while avoiding the worst limitations of each. Our approach uses a database of designs and process plans that are classified using design signatures, graphical structures based on detailed product design attributes that are more meaningful and accurate than GT codes and can be computed automatically from the designs stored in the database. We are developing ways to use design signatures to classify and retrieve “slices” of designs and plans, so that when a process plan is needed for a new design, we will be able to retrieve the plan slices that are most relevant, and combine them and modify them to produce a plan for the new design.
OSCAP: An Environment for Manufacturing Planning of Mechanical Products
Authors: Yang Zhi-Xin , Joneja Ajay 
Published: February 2021

Abstract
This paper describes an open-architecture system for computer-aided process planning called OSCAP. The system is different in architecture from traditional integrated process planning systems, since it is designed specifically to integrate with existing partial planning software with little effort. It does provide all functions of design and process planning for machining of mechanical parts on 3-axis machining centers. Special features of the system include a sophisticated feature recognition system, an optimal machining planner, automated fixture synthesis, setup planning with operation sequencing, and a knowledge based system organizer called the OSCAP core which orchestrates the functioning of all modules. The system can be arbitrarily extended or collapsed by adding or removing functional modules.
Knowledge-Based Design Tool to Support Integrated Manufacturing
Authors: Allada Venkat 
Published: February 2021

Abstract
Advanced CAD design tools that facilitate designers to produce manufacturable designs right the first time are needed to compress product realization cost and time. Such tools must facilitate artifact diagnosis regarding its manufacturability during early design stages. This study focuses on identifying the major issues in the development of a knowledge-based design tool to evaluate artifact manufacturability. A prototype integrated design and manufacturing (IDM) system has been developed for conducting machined part evaluation. The IDM system is implemented on a SunSparc 20 workstation using the ACIS v1.7 geometric modeler, the C++ programming language, and MOTIF. The concepts of feature flexibility and feature importance introduced in this study can be used to provide appropriate context-sensitive “intelligent” repair (redesign) advice to the designer after identifying portions of a design artifact that are difficult/impossible to manufacture. A preliminary discussion on the issue of ranking of redesign solutions based on designer’s objective functions is also presented.
FixtureNet II: Interactive Redesign and Force Visualization on the Web
Authors: Anderson Charles , Zhuang Yan , Goldberg Ken 
Published: February 2021

Abstract
Digital communication over the Internet offers advantages in terms of speed, efficiency and automation. Fortunately, new geometric algorithms for design, simulation, and manufacturing have been developed and reported in the research literature. Unfortunately, the impact of these advances on the manufacturing community has been limited since implementations are difficult to port from one platform to another.
As an example of how the Web can facilitate interactive design, we focus on one specific application area: modular fixture design. We have substantially extended our previous fixture design service, FixtureNet (Wagner et al., 1996), and added interactive tools to allow the user to build a deeper, more intuitive understanding of the fixtures found by FixtureNet. The first tool allows the user to simulate the effects of forces applied to the part in the fixture. Our second tool enables the user to consider changes to a part and verify in real-time that the fixture will still immobilize the modified part.
Our tools balance the tasks between the Web client and a central server, performing fast user interactions in the client while running compute-bound fixture design jobs on the server.
The implementation of this work can be found online at: http://riot.ieor.berkeley.edu/riot/Applications/FixtureNet.
Non-Verbal Transfer of Skill
Authors: Fukuda Shuichi , Matsuura Yoshifusa , Takahashi Tokiko , Wongchuphan Premruedee 
Published: February 2021

Abstract
It is becoming more and more important to consider how we should integrate our knowledge of skills into design, if we really wish to integrate design and manufacturing, because skills play very important roles in manufacturing. Although there are many design systems available, most of them deal only with the symbolic representation of our knowledge and even such media as TV, video, etc. which are considered to be good for skill representation are still in most cases one way from a teacher to a student. To really learn a skill, feedback from a student to a teacher should be established and more interactiveness secured.
We developed a prototype system with the simple example of learning the skill of penmanship for the purpose of clarifying the problems of skill representation and with the hope of integrating skill knowledge into design in the future.
Networkcentric Buddy System for Collaboration
Authors: Fukuda Shuichi , Matsuura Yoshifusa , Kandie Kigen , Nakajima Yoshiyuki 
Published: February 2021

Abstract
With the increasing diversification, complexity and globalization of our society, distance learning is gathering wide attention because it is expected it will provide a very flexible learning environment.
But most of the conventional distance learning systems are still of such presentation types as TV, Video, etc, which passes information only from a teacher to students, and they are developed without any consideration to the interaction among students. Thus, although the system may be described as being the system for one to many relation, the fact is that a teacher has to take care of each student independently so that the burden of a teacher increases tremendously with the increase of the number of students.
Although TV conferencing type systems have been introduced into the area of distance learning recently, the consideration of the interaction among students is still poor.
In the conventional classroom, at least in Japan, not only teacher-student relation is important, but also student-student relation is none the less important, because it will constitute a buddy system among themselves and they learn interactively by playing the role of a teacher from time to time. And this serves a great deal in letting them find important points by themselves and raise new questions.
This has an advantage on the part of a teacher, too, because it will greatly reduce his or her burdens, and make it possible for him or her to adapt to each classroom situation and change their pace or contents of teaching.
Therefore, we developed a networkcentric prototype system for interactive distance learning, considering not only interaction between a teacher and a student but also among students. This system will largely reduce the burden of a teacher because it will facilitate the collaboration in learning among students and because it is developed based on a client/server approach and by evaluating the progress of each student.
The introduction of a client/server approach makes it possible to manage the personal records of each student’s achievement level on a server and to construct a hierarchical structure automatically based upon them. Thus, well advancing students can play the role of a teacher when needed and students can learn very interactively and very collaboratively, thus reducing the burden of a teacher to a great extent.
It should be stressed that the same kind of problems arise between a designer and manufacturing engineers. Up to now, our information flow is one way from designer to manufacturing engineers and although concurrent engineering succeeded in realizing interactions between designers and manufacturing engineers, the interaction between manufacturing engineers are still very poor so that it will eventually increase the burden of designers which will result in poor quality design or in poor decision making at the earlier stages.
Enabling Virtual Reality for Large-Scale Mechanical CAD Datasets
Authors: Varshney Amitabh , El-Sana Jihad , Evans Francine , Darsa Lucia , Costa Bruno , Skiena Steven 
Published: February 2021

Abstract
Reconciling scene realism with interactivity has emerged as one of the most important areas in making virtual reality feasible for large-scale mechanical CAD datasets consisting of several millions of primitives. This paper surveys our research and related work for achieving interactivity without sacrificing realism in virtual reality walkthroughs and flythroughs of polygonal CAD datasets. We outline our recent work on efficient generation of triangle strips from polygonal models that takes advantage of compression of connectivity information. This results in substantial savings in rendering, transmission, and storage. We outline our work on genus-reducing simplifications as well as real-time view-dependent simplifications that allow on-the-fly selection amongst multiple levels of detail, based upon lighting and viewing parameters. Our method allows multiple levels of detail to coexist on the same object at different regions and to merge seamlessly without any cracks or shading artifacts. We also present an overview of our work on hardware-assisted image-based rendering that allows interactive exploration of computer-generated scenes.
Real-Time Particle Simulation for Virtual Environments
Authors: Assadi Armand D. , Oliver James H. 
Published: February 2021

Abstract
A real-time interactive environment for particle simulation is presented with specific attention given to fluid flow from a fountain system. The complex Navier-Stokes equations from fluid dynamics theory give way to simple dynamic equations of motion for systems of independent particles from particle theory. Due to the ease of integration of the dynamic linear first order differential equations, compared to the nonlinear second order partial differential equations of Navier-Stokes, a real-time rate was achieved for a visually aesthetic model of fluid flow. The primary contribution is that interactive changes made by the user are perceived to occur simultaneously in the environment. There is no need to resolve a predetermined set of equations when making the changes.