bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computer-Aided Displacement Analysis of Spatial Mechanisms
Authors: Thompson Sean , Cheng Harry H. 
Published: March 2021

Abstract
Recently, Cheng (1993) introduced the CH programming language. CH is designed to be a superset of ANSI C with all programming features of FORTRAN. Many programming features in CH are specifically designed and implemented for design automation. Handling dual number as a basic built-in data type in the language is one example. Formulas with dual numbers can be translated into CH programming statements as easily as formulas with real and complex numbers. In this paper we will show that both formulation and programming with dual numbers are remarkably simple for analysis of complicated spatial mechanisms within the programming paradigm of CH. With computational capabilities for dual formulas in mind, formulas for analysis of spatial mechanisms are derived differently from those intended for implementation in computer programming languages without dual data type. We will demonstrate some formulation and programming techniques in the programming paradigm of CH through a displacement analysis of the RCRCR five-link spatial mechanism. A CH program that can obtain both numerical and graphical results for complete displacement analysis of the RCRCR mechanism will be presented.
Automatic Bar Stock Selection for Machining
Authors: Leonard John E. , Shah Jami J. 
Published: March 2021

Abstract
Given a feature-based CAD model of a part’s geometry, the problem is to select the shape and size of bar stock from which the part can be made. It is assumed that standard stock shapes and sizes available in the workshop varies, so the task is to select the best suited stock geometry and cut-off length from the available inventory. Automatic workpiece selection involves the interrogation of a part database to determine the part’s shape characteristics, and to match the shape with available geometries. The requirements of a system to perform this task are presented along with several methods of determining the appropriate shape — GT coding, shrinking box, silhouette projection, point network, principal machining directions, and face extension. None of these methods is sufficiently robust by itself, so a combination of methods is required. Based on this hybrid technique, a system to perform automatic workpiece selection was designed and implemented. A coding scheme is used to select the workpiece shape, based on primary features and their relationships. Once the shape is selected, it is matched with available workpiece shapes. The workpiece is then sized using a version of the bounding box method.
Algorithms to Detect Geometric Interactions in a Feature-Based Design System
Authors: Talwar Rajeev , Manoochehri Souran 
Published: March 2021

Abstract
This paper presents efficient and accurate algorithms for the analytical detection of geometric interactions between features in a CAD environment. The developed methodology is meant to be utilized in a knowledge-based design system using feature-based modeling. The algorithms take surface information from the CAD system and use geometric inferencing to evaluate these interactions. Features represented by both convex and concave polyhedra are considered. The methodology developed here is able to deal with concave features effectively and, therefore, eliminates the need for their decomposition into convex sub-features. Sets of conditional statements based on simple and elegant rules have been developed to distinguish different types of interactions. Feature interactions are classified as intersecting or non-intersecting. For the non-intersecting cases, the features can be contained or separate and, for both cases, they can touch each other through an edge, a vertex and/or a surface. For the intersecting cases, intersections through a surface, an edge, a common edge and a common surface are identified. For all the cases the vertices, edges and surfaces involved in the interactions are identified and the relevant distances are evaluated. A computer program has been successfully implemented for polyhedral features and examples have been given to demonstrate its effectiveness.
Behavior of Structures Using Simple Plastic Hinge Theory
Authors: Maruthayappan Ramakrishnan , Lankarani Hamid M. 
Published: March 2021

Abstract
The behavior of structures under the impact or crash situations demands an efficient modeling of the system for its behavior to be predicted close to practical situations. The various formulations that are possible to model such systems are spring mass models, finite element models and plastic hinge models. Of these three techniques, the plastic hinge theory offers a more accurate model compared to the spring mass formulation and is much simpler than the finite element models. Therefore, it is desired to model the structure using plastic hinges and to use a computational program to predict the behavior of structures. In this paper, the behavior of some simple structures, ranging from an elementary cantilever beam to a torque box are predicted. It is also shown that the plastic hinge theory is a reliable method by comparing the results obtained from a plastic hinge model of an aviation seat structure with that obtained from a finite element model.
Feature-Based Design for Mill-Turn and 3-Axis Machining
Authors: Henderson D. L. , Anderson D. C. 
Published: March 2021

Abstract
A feature-based design environment for machined parts exploiting the capabilities of mill-turn machining centers is described. Part models for prismatic, turned and mill-turn parts, as well as hybrid parts such as turned parts with prismatic features, are created with parametrically defined features. Two-dimensional (2-D) profile features are used for creating surfaces of revolution for turned parts. Mill-turn features can be added to cylindrical base features, and traditional prismatic features, such as slots and holes, can be used with prismatic or cylindrical parts. Features are hierarchically positioned and oriented in a unified scheme that includes position and form tolerances. The vector-based tolerance representation facilitates interactive three-dimensional (3-D) design and provides information needed by downstream applications, such as automatic process planning and inspection.
Geometric Influence of a Molded Part on the Draw Direction Ranges and Parting Line Locations
Authors: Weinstein Marc , Manoochehri Souran 
Published: March 2021

Abstract
This paper presents a methodology based on the geometry of the injection molded part to identify the draw direction range and parting line locations. These parameters are shown to be a function of the interaction of the outward normals of the surfaces which have been divided into concave and convex regions of the part. This approach can also be applied incrementally to determine these mold parameters for a part as design features are added. The designer can then select from the choices provided to find the optimum parting line location and draw direction using heuristic rules. An absence of an allowable draw direction indicates the presence of an undercut which complicates the mold by requiring a side action so that the mold cost increases. The designer can either redesign the part or accept the undercut by specifying a side core or cavity. Design examples are provided which illustrate the effectiveness of the developed approach.
A Knowledge-Based Approach to Design Partial Journal Bearings
Authors: Badar M. Affan , Guntur Rao R. 
Published: March 2021

Abstract
Various methods for designing hydrodynamic partial journal bearings are reviewed and an integrated and dependable design procedure is (developed. Knowledge and rule bases pertaining to the design of journal bearings having arcs of 180°, 120°. and 60° are either gathered or derived and represented properly. An expert system is developed using the databases and rulebases. The bearing design is based on one of the following decision criteria: the maximum load, the minimum friction, or the optimal clearance The expert system makes an exhaustive search for all the design solutions. Utility value of each of the final solutions is calculated and the design solutions having utility values above a certain limit are stored The results are presented to demonstrate the usefulness of the knowledge-based approach.
Configuration Design of Structures Using Discrete Optimization Approach
Authors: Shim Patrick Y. , Manoochehri Souran 
Published: March 2021

Abstract
This paper presents a methodology for the generation of fully stressed shape configuration design of structures. An important aspect of this approach is the ability to modify the topology as well as the boundary shape of the object represented by a finite element model Therefore, features such as holes or slots can be added even though they have not been part of the initial model. This work is based on altering the finite element structure by removing or restoring elements to generate fully stressed designs subject to constraints on maximum stress value and maintenance of connectivity between the elements. The algorithm uses binary value integer programming for the discrete optimization process with the normalized elastic modulus of each design element selected as design variable. The optimization results consist of a zero or one integer solution which indicates the states or the elements in the model The integer zero indicates that the modulus of the design element is zero and therefore the element is a candidate for deletion from the model The integer one represents no change in modulus value compared to the original model and thus these design elements stay in the model. The developed approach can modify the inner and the outer shape of the structure without the need for a remeshing after each iteration and this reduces the computational time significantly. Design examples are provided to demonstrate the effectiveness of the proposed optimal design methodology and to illustrate the steps involved in this process.
Multiple Objective Design Optimization by Estimating Local Utility Functions
Authors: Yang Jian-Bo , Sen Pratyush 
Published: March 2021

Abstract
This paper presents the application of an interactive multiple objective decision making (MODM) procedure to design synthesis. This procedure is composed of an interactive step trade-off method (ISTM) and the estimation of local utility functions. The ISTM method is used as a preference learning process to assist a designer (decision maker or DM) in generating a representative sub-set of efficient designs (solutions). In this learning process, the DM is expected to compare the generated solutions in a pairwise manner to express his preferences. A set of additive local utility functions are then estimated to help the DM search for his best compromise solution. A multiple objective design synthesis problem is examined using the procedure.
A Survey of Electronic Package Manufacturing Analysis Methods Suitable for Integration With Multidisciplinary Optimization
Authors: Korngold Jacob , Gabriele Gary A. 
Published: March 2021

Abstract
The objective this paper is to improve concurrent engineering of electronic packaging design problems by addressing issues of integrating manufacturing as a discipline in multidisciplinary design analysis and optimization (MDA/O) problems. To met this goal, MDA/O and electronic package manufacturing analysis modules are examined. Manufacturing can participate as a discipline in MDA/O problems if analysis capability exists to relate design variables to quantitative manufacturing performance metrics. Analysis modules for sheet metal enclosure and printed circuit board fabrication were found to meet these requirements. In formulating MDA/O problems with manufacturing as a discipline, questions arise about the role of manufacturing analysis, design variables selection, performance metrics, and constraint definitions. Answering these questions is the subject of continuing research.
On Global Design Description for Orientational Strength Optimization
Authors: Pedersen Pauli , Hammer Velaja B. 
Published: March 2021

Abstract
The idea of global design description used frequently in shape optimization, is extended from curve to surface parametrization. The design is given as a linear combination of orthogonal functions. Application to orientational design of laminates for strength optimization is used as an example, but the technique is directly applicable to design also of thickness distribution. The advantages by this design description are many, including control on smoothness, control on slopes, and control on connections at the boundaries. This simplified parametrization of the design makes it possible to work with only a few design variables, say 25 for a whole design domain.
Intrinsic Geometry for Shape Optimal Design With Analysis Model Compatibility
Authors: Widmann James M. , Sheppard Sheri D. 
Published: March 2021

Abstract
This paper presents a comparison of geometric modeling techniques and their applicability to structural shape optimization. A method of shape definition based on intrinsic geometric quantities is then outlined. Explicit knowledge of curvature and arc length allow for a quantitative assessment of the compatibility of analysis model with the design model when using finite elements to determine structural response quantities. The compatibility condition is formalized by controlling finite element idealization error and is incorporated into the shape optimization model as simple bounds on the curvature design variables. Several examples of shape optimization problems are solved using sequential quadratic programming which proves to be an effective tool for maintaining the geometric equality constraints that arise from intrinsically defined curves.
An Approach to the Problem of Vibration: Structural Modification by Optimizing Density Distribution
Authors: Kawabe Yoshiko , Yoshida Shinobu 
Published: March 2021

Abstract
This paper proposes a basic method for designing light and rigid structures that maximize the natural frequency of the structure for a designated mode. A design variable ‘density’ is introduced into the finite element method and is related to the material properties of a 3-dimensional solid element. Thus, a structure is expressed as a density distribution inside its occupiable domain, and the optimal structure is obtained by searching for the most suitable density distribution. The dynamic characteristics of the structure are improved by repeatedly modifying its density distribution.
Application of Genetic Algorithm for the Support Location Optimization of Beams
Authors: Wang Bo Ping , Chen Jahau Lewis 
Published: March 2021

Abstract
Genetic algorithms are adaptive procedures that find solutions to problems by an evolutionary process that mimics natural selection. In this paper, the use of genetic algorithms for the selection of optimal support locations of beams is presented. Both elastic and rigid supports are considered. The approach of adapting the genetic algorithms into the optimal design process is described This approach is used to optimize locations of three supports for beam with three types of boundary conditions.
A New Design of a Bicycle Frame: An Example for an Effective Layout Procedure Based on FE-Simulation of Biological Growth
Authors: Baumgartner A. , Mattheck C. 
Published: March 2021

Abstract
On the basis of the axiom of constant stress two optimization procedures have been developed for the improvement of technical load carriers. Specially the goals of lightweight design and high fatigue resistance are considered.
The SKO method generates lightweight structures for a defined loadcase by simulating the adaptive mineralization of bones. A subsequent shape optimization with the CAO method results in a design with a homogeneous stress distribution on the surface. This prevention of localized high stresses leads to a considerable increase in fatigue life. With the example of a new bicycle frame the efficiency of a combination of both to a complete layout procedure is demonstrated.
Activity-Based Costing in Design for Product Retirement
Authors: Emblemsvåg Jan , Bras Bert 
Published: March 2021

Abstract
In this paper, an approach is presented to estimate the cost incurred by different designs based on Activity-Based Costing (ABC). The suitability of utilizing ABC in design is explored in the context of design for product retirement. A comparison is made with a number of approaches for estimating product life-cycle cost. In comparison to other costing schemes, ABC has the advantages that it can trace both direct and indirect (overhead) costs correctly back to where these costs actually were incurred. This ‘traceability’ facilitates the identification of the most cost inefficient parts of the design, which makes ABC much more suitable for design decision making than other costing schemes. In general, ABC is also more accurate. Although the costs related to any part of a product’s life-cycle can be estimated, an automobile product retirement example is used to illustrate the usage of the approach described. In the example, a decision has to be made whether to pursue a recyclable car or a non-recyclable car. Future work is identified, primarily related to the inclusion of uncertainty in the approach presented.
New Adaptive Tools Dedicated to Surfacic Meshes Integrated Into a C.A.D. Environment
Authors: Noël Frédéric , Léon Jean-Claude , Trompette Philippe 
Published: March 2021

Abstract
The integration of CAD information and Finite Element Analysis is one of the important problems addressed by the design automation requirements. In case of parts involving free-form surfaces, the creation and adaptation of a mesh are still one of the bottlenecks attached to the search for competitive design.
A solution is proposed which inserts a mesh adaptation software into the CAD-FEA chain. Full geometric data of free-form surfaces is used as input together with an initial approximate mesh. Geometric and mesh information on their own, as well as together, use extensively the concept of classification introduced here. Furthermore, topologically and geometrically layered adaptation tools are provided which achieve radaptivity, mesh coarsing, mesh refinement and edge swapping treatments.
The toolkit thus available is demonstrated on examples and its integration requirements are all developed along its description.
Planning Near Time-Optimal Trajectories for Robot Manipulators Along Given Paths
Authors: González-Baños Héctor H. , Gordillo José-Luis 
Published: March 2021

Abstract
This paper extends a previous method aimed to compute discrete time-optimal trajectories of “dot-like” robots to consider the general case of robotic manipulators. The resulting trajectories provide the torque command at each actuator for following a given path in minimum time while respecting the constraints imposed by the manipulator model.
The proposed method makes use of a modified manipulator dynamic model in terms of γ, the arc length parameter which defines the trajectory in the joint space q. The search for a solution is done in the space specified by γ and its derivative ν (the pseudo-speed scalar). In this space we define the features of the solution in order to design an efficient algorithm to compute the time-optimal trajectory. We determine bounds to the model components, such that the optimal solution lies below a curve limiting the area Ω, area in which all possible solutions fit.
The algorithm performs, inside Ω, an ascendent search of the limiting curve; this strategy permits the curve obtained at each intermediate step to be a valid solution.
A Scheme of a Knowledge Based System for Optimal Modelling and Design of Robots
Authors: Lawo Michael 
Published: March 2021

Abstract
Based on a finite element model the deformations and vibrations of a robot structure are calculated for different configurations (layouts). The results of the analysis are verified by measuring the corresponding deformations and velocities. The time history of velocities at different points of the structure in test positions is recorded. Out of the time history by modal analysis the natural frequencies are determined. The structural model is checked by the comparison of corresponding analysed and measured values A nonlinear optimization method with the structural parameters as variables of the model is used for the solution of this identification problem. The result is a verified and sufficient structural model of the real structure. Out of the experiences a knowledge based system for the modelling and simulation of robot structures is conceived. The concept of the system is presented.
Feasibility Study of Crash Optimization
Authors: Yang R. J. , Tseng L. , Nagy L. , Cheng J. 
Published: March 2021

Abstract
A feasibility study of using numerical optimization methods for crash analysis is presented. Software required for numerical optimization includes parametric modeling (Pro/ENGINEER), automatic mesh generation (PDA/PATRAN3), nonlinear finite element analysis (RADIOSS), and optimization methods (CONMIN & DOP). Both single- and multiple-objective formulations are used for numerical optimization and result in better designs. It was found that crash optimization is feasible but costly and that finite element mesh quality is essential for successful crash analysis and optimization. A simplified front horn was used to demonstrate this approach.
Bézier Curves on Riemannian Manifolds and Lie Groups With Kinematics Applications
Authors: Park Frank C. , Ravani Bahram 
Published: March 2021

Abstract
In this article we generalize the concept of Bézier curves to curved spaces, and illustrate this generalization with an application in kinematics. We show how De Casteljau’s algorithm for constructing Bézier curves can be extended in a natural way to Riemannian manifolds. We then consider a special class of Riemannian manifold, the Lie groups. Because of their algebraic group structure Lie groups admit an elegant, efficient recursive algorithm for constructing Bézier curves. Spatial displacements of a rigid body also form a Lie group, and can therefore be interpolated (in the Bezier sense) using this recursive algorithm. We apply this algorithm to the kinematic problem of trajectory generation or motion interpolation for a moving rigid body.
Five Position Synthesis of Spatial CC Dyads
Authors: Murray Andrew P. , McCarthy J. Michael 
Published: March 2021

Abstract
This paper presents a new technique for determining the fixed axes of spatial CC dyads for rigid body guidance through five finitely separated positions. A CC dyad is a kinematic chain consisting of a floating link connected by a cylindric joint to a crank which in turn is connected to ground by a second cylindric joint. The lines that can be axes of the fixed joint are shown to be obtained from a “compatibility platform” constructed from selected relative screw axes associated with the five specified displacements. We show that the screw axis of the displacement of this platform is a fixed axis of a CC dyad compatible with the five positions. Roth’s original example is presented to verify the calculations. The specialization of this procedure to planar and spherical five position synthesis is also presented.
Application of Fuzzy Set Theory to Planar and Spatial Mechanism Design
Authors: Krishna Kota Murali , Krishnamurthi Subramanyam , Kramer Steven N. 
Published: March 2021

Abstract
This paper describes how Fuzzy Set Theory and Fuzzy Numbers can be applied to the synthesis of planar and spatial mechanisms. The main advantage of using Fuzzy Set Theory over other methods of mechanism synthesis is that uncertainties in positions, rotations and link lengths can be quantified using the concept of membership functions. A membership function is an explicit representation of the deviation of the value of a parameter from its specified value. Numerical examples include the synthesis of a four-bar path generating mechanism with uncertain prescribed timing as well as uncertain path points and the RSSR spatial function generating mechanism. This work is expected to be a significant contribution to optimal mechanism design.