bluuebunny/crossref_metadata_2025_split huggingface dataset:
Workspace-Based Design of Parallel Manipulators of Star Topology With a Genetic Algorithm
Authors: Baron Luc 
Published: November 2020

Abstract
This paper presents the results of the implementation of a genetic algorithm for the design of parallel manipulators of Star topology based on the characteristics of its workspace (W). The algorithm allows to propose new geometries of manipulators that maximize the weighted sum of the volume of W, the percentage of W having a dexterity index greater than a minimum threshold, and a shape ration of W. The algorithm has proven to be effective by proposing a new design that overcomes, by a factor of 3.636, the performances of the original Y Star design, after evaluating the performances of only 2000 alternative designs, which correspond to a traveling of only 2.02 × 10−16% through the search space of this design problem.
Computationally Inexpensive Metamodel Assessment Strategies
Authors: Meckesheimer Martin , Barton Russell R. , Simpson Timothy W. , Booker Andrew J. 
Published: November 2020

Abstract
In many scientific and engineering domains, it is common to analyze and simulate complex physical systems using mathematical models. Although computing resources continue to increase in power and speed, discipline-specific computer simulation modules continue to grow in complexity and remain computationally expensive, limiting their use in design optimization. The use of different approximation strategies as inexpensive metamodels of the discipline-specific simulation models has led to the development of various metamodel-based integration frameworks and associated research topics. In particular, integration of the discipline-specific metamodels requires an assessment of the overall system error based on the individual approximation errors. As a result, there is a need to develop efficient methods to assess metamodel fidelity at the system and subsystem level. In this paper, we investigate computationally inexpensive assessment methods for metamodel validation at the subsystem level and evaluate a two-stage validation approach on two classes of test problems:
1. Three response functions from a Boeing simulation model, and
2. two response functions from a set of problems for testing optimization codes.
Preliminary results indicate that the two stage-validation approach is promising, since it requires no additional computationally expensive disciplinary model evaluations and can provide a practical estimate of the true error measure.
Optimization for Minimum Weight of Ultralight Structures Under Axial Crush Loading
Authors: Chen Weigang 
Published: November 2020

Abstract
A methodology was proposed which combined the structural optimization technique with the recent achievements in crush mechanics of thin-walled members with ultralight metal filler. The optimization problems of foam-filled square, hexagonal, double-hat rectangular, double-hat hexagonal sections and double-walled sandwich sections were formulated and solved with crashworthiness and bending stiffness constraints. The proposed methodology requires relatively simple computations and is suitable for early stage design of crash members. The optimization results showed potentials of significant weight saving and volume reduction by utilizing ultralight metal filler. The double-walled sandwich sections appear to be the most weight efficient design with the highest specific energy absorption among all studied cross-sections.
Computational Performance of Wavelet-Based Meshless Methods in the Solution of Very Large Scale Elasticity Problems
Authors: Diaz Alejandro R. , Yamaura Kazuya 
Published: November 2020

Abstract
This paper discusses the computational performance of methods to solve very large scale, geometrically complex problems in elasticity using a voxelization of the domain and wavelet based discretizations. These methods are designed to avoid the complexities associated with the construction of standard finite element meshes. Results show that in very large scale problems these schemes converge more rapidly than a standard (finite element) method.
Packing Optimisation Using a Rubberband Analogy
Authors: Fadel Georges M. , Sinha Avijit , McKee Todd 
Published: November 2020

Abstract
Packing is a topic of interest in many fields. During our research on the underhood-packing problem, we observed that to bring components together — without switching their relative position — one could use the analogy of a rubber object stretched around the artifacts. In two-dimensional space, that object is a rubber band, and in three-dimensions, it is a balloon. Using this analogy, the convex hull can be used to determine the direction of forces applied to a single component, and a motion can result from the application of such forces. The objects can then be moved until contact occurs, at which point the forces become moments, and the objects can rotate with respect to each other. This technique can guarantee locally optimal packing, and displays a very intuitive behavior that might lead to further advances in optimization. This paper introduces the methodology for optimizing the packing of 2-dimensional geometric entities (polygons) in a plane and of 3-dimensional objects in space using the Rubber band Analogy.
Design of Multifunctional Compliant Mechanisms for Minimally Invasive Surgery
Authors: Dziedzic Ryan P. , Frecker Mary I. 
Published: November 2020

Abstract
This paper proposes incorporating compliant mechanisms into the design of minimally invasive surgical tools to help overcome current tool limitations — particularly to increase multifunctionality. To perform multiple unique functions, a compliant mechanism is designed with a single topology that allows multiple input forces to independently produce distinct output displacements. A multicriteria topology optimization procedure is developed for the design of compliant mechanisms, and the procedure is executed using Matlab. This method generates topologies displaying both sufficient compliance and stiffness for each load case by formulating the objective function as a ratio of mutual potential energy to strain energy. The total objective function is then assembled as the weighted sum of the objective functions for each load case. The optimization procedure is illustrated through the generation of topologies for a device based on a grasperscissors combination tool. Also addressed are factors which significantly influence the resulting solution, such as the weighting function value and starting point.
Finding and Removing Features From Polyhedra
Authors: Ribelles José , Heckbert Paul S. , Garland Michael , Stahovich Tom , Srivastava Vinit 
Published: November 2020

Abstract
Geometric models of solids often contain small features that we would like to isolate and remove. Examples include bumps, holes, tabs, notches, and decorations. Feature removal can be desirable for numerous reasons, including economical meshing and finite element simulation, analysis of feature purpose, and compact shape representation. In this work, an algorithm is presented that inputs a polyhedral solid, identifies and ranks its candidate features, and outputs solid models of the feature and the original object with the feature removed. Ranking permits a user or higher level software to quickly find the most desirable features for the task at hand. Features are defined in terms of portions of the surface that are classified differently from the rest of the solid’s surface with respect to one or more split planes. This approach to feature definition is more general than many previous methods, and generalizes naturally to quadric surfaces and other implicit surfaces.
Investigation of Compliant Centrifugal Clutch Designs
Authors: Crane Nathan B. , Weight Brent L. , Howell Larry L. 
Published: November 2020

Abstract
Compliant centrifugal clutches can make centrifugal clutches feasible in cost and weight sensitive applications. This paper introduces new configurations of compliant centrifugal clutches, proposes pseudo-rigid-body models for their analysis, and presents torque capacity results for several prototypes. The results are also compared to those obtained from compliant centrifugal clutch designs already commercially available. While all four new clutch designs compare favorably to commercially available clutch configurations, the floating opposing arm (FOA) clutch demonstrated the highest torque capacity of all the configurations.
Comparative Study of Seismic Analyses for Piping Systems
Authors: Jonsdottir Fjola , Jonsson Magnus Thor 
Published: November 2020

Abstract
In this paper different approaches in seismic design are investigated. Commonly used static analysis is compared with two different cases of harmonic analysis. The static analysis is based on a design response spectra. In the harmonic analysis, case 1, the loading is in the form of acceleration applied to the mass, for case 2, the loading is in the form of applied displacements to the supports. A typical expansion pipe unit is analysed with all three methods. It is shown that standard procedures can lead to a conservative design and prevent the optimization of the results. An optimum design can be obtained by using supports with adequate damping and stiffness, and hence, the loading on the piping system can be minimized.
Analytical Target Cascading in Automotive Vehicle Design
Authors: Kim Hyung Min , Rideout D. Geoff , Papalambros Panos Y. , Stein Jeffrey L. 
Published: November 2020

Abstract
Target cascading in product development is a systematic effort to propagate the desired top-level system design targets to appropriate specifications for subsystems and components in a consistent and efficient manner. If analysis models are available to represent the relevant design decisions, analytical target cascading can be formalized as a hierarchical multilevel optimization problem. The article demonstrates this complex modeling and solution process in the chassis design of a sport-utility vehicle. Ride quality and handling targets are cascaded down to systems and subsystems utilizing suspension, tire, and spring analysis models. Potential incompatibilities among targets and constraints throughout the entire system can be uncovered and the trade-offs involved in achieving system targets under different design scenarios can be quantified.
Large-Scale, Multidisciplinary Optimization of a Vehicle System in a Scalable, High Performance Computing Environment
Authors: Kodiyalam Srinivas , Yang R. J. , Gu Lei , Tho Cheng-Ho 
Published: November 2020

Abstract
The focus of this paper is on large-scale MDO of a vehicle system for Safety, NVH (noise, vibration and harshness) and Weight, in a scalable HPC environment. The computational complexity comes from addressing multiple safety modes including, frontal crash, offset crash, side impact and roof crush, in addition to the NVH discipline. A combination of high performance computing utilizing several hundred processors, Kriging metamodeling based design response approximation techniques, formal MDO strategies, and engineering judgement are effectively used to obtain superior design solutions with significantly reduced elapsed computing times. The reduction in large-scale MDO solution times through HPC is significant in that it now makes it possible for such technologies to impact the vehicle design cycle and improve the engineering productivity.
A Multi-Project Management Approach for Distributed Projects Management
Authors: Marie Franck , Bocquet Jean-Claude 
Published: November 2020

Abstract
As planning is the action undertaken before execution, it has a great importance as every investment. We identify some problematics in the planning process, and give some lightings about how to make it more efficient and reliable. We propose some methods for managing project at each detail level. We propose the extension of project manager’s concepts to all the people who are accountable for some objective or deliverable. So, there are in a single project a lot of people managing the part they are responsible for as an entire project. We propose a standard methodological kit for them, and we describe the consequences on skills and responsibilities of the project actors, and on the decisions they have to take and efforts they have to undertake to reach their objectives.
Classification of Designs for RRSS Linkages
Authors: Su Haijun , McCarthy J. Michael 
Published: November 2020

Abstract
This paper presents a classification of designs for an RRSS spatial linkage. The analysis of this linkage results in a well-known constraint equation that defines the configuration of the chain for given values of the input crank angle. The range of movement of this crank is defined by a condition on the values of the input crank angle. This condition is a quartic polynomial and its real roots provide a way to classify the movement of the RRSS linkage. This condition yields as many as four real roots, which means the input crank angle of an RRSS linkage can have up to four limits to its range of movement. We use three polynomial discriminants obtained from this quartic condition in order to find explicit conditions for all cases available for the movement of the input crank. Examples for each case are provided. This result provides a means to classify the RRSS linkage, and is important for the computer-aided-design of these spatial mechanisms.
Utility-Based Decision Support for Selection in Engineering Design
Authors: Fernández Marco Gero , Seepersad Carolyn Conner , Rosen David W. , Allen Janet K. , Mistree Farrokh 
Published: November 2020

Abstract
In this paper we present a utility-based method for selection in engineering design. The Utility-Based Selection DSP supports a designer in making selection decisions involving both tradeoffs among multiple, conflicting attributes and risk or uncertainty associated with these attributes. The method is quantitative as well as axiomatic, designed to facilitate rational decision-making that is consistent with assessed designer preferences. We illustrate use of the Utility-Based Selection DSP through application in a rapid prototyping context. The goal here is to select appropriate rapid prototyping technology and material combinations for testing the snap-fit design of a light switch cover plate. Overall, our focus is to present both method and example in sufficient detail for application by others.
Capturing Assembly Tolerances and Criteria in a Common Model
Authors: Morse Edward P. 
Published: November 2020

Abstract
Assemblies of mechanical parts are typically modeled as collections of rigid solids, constrained by contact conditions at “mating” faces. We have previously proposed a method — called GapSpace — of modeling and representing assemblies with constraints arising from either face adjacency or face contact. This method of specification allows less restrictive tolerances to be placed on the assembly components, resulting in specifications that are less expensive to meet. In this paper we show how various assembly metrics and criteria can be represented with GapSpace, and how to analyze toleranced assemblies for conformance to these criteria. These analyses show quantitatively the importance of deciding which part dimensions will have tolerances applied to them, in addition to the choice of the actual tolerance values.
Geometric Insight Into the Dynamics of a Rigid Body Using the Spatial Triangle of Screws
Authors: Pennock Gordon R. , Meehan Patrick J. 
Published: November 2020

Abstract
Geometric relationships between the velocity screw and momentum screw are presented, and the dual angle between these two screws is shown to provide important insight into the kinetics of a rigid body. Then the centripetal screw is defined, and the significance of this screw in a study of the dynamics of a rigid body is explained. The dual-Euler equation, which is the dual form of the Newton-Euler equations of motion, is shown to be a spatial triangle. The vertices of the triangle are the centripetal screw, the time rate of change of momentum screw, and the force screw. The sides of the triangle are three dual angles between the three vertices. The spatial triangle provides valuable geometrical insight into the dynamics of a rigid body and is believed to be a meaningful alternative to existing analytical techniques. The authors believe that the work presented in this paper will prove useful in a dynamic analysis of closed-loop spatial mechanisms and multi-rigid body open-chain systems.
Multidisciplinary Robust Design Optimization of an Internal Combustion Engine
Authors: McAllister Charles D. , Simpson Timothy W. 
Published: November 2020

Abstract
In this paper, we introduce a multidisciplinary robust design optimization formulation to evaluate uncertainty encountered in the design process. The formulation is a combination of the bi-level Collaborative Optimization framework and the multiobjective approach of the compromise Decision Support Problem. To demonstrate the proposed approach, the design of a combustion chamber of an internal combustion engine containing two subsystem analyses is presented. The results indicate that the proposed Collaborative Optimization framework for multidisciplinary robust design optimization effectively attains solutions that are robust to variations in design variables and environmental conditions.
Mouth Operated Neurosurgical Robot
Authors: Sugar Thomas G. , Fussell Paul 
Published: November 2020

Abstract
Medical robots in neurosurgery are currently used to accurately position a microscope in consonance with MRI images to allow positional awareness relative to important features of surgical focus. Currently, these robots must be “hand” adjusted by the surgeon, unlike the mouth-operated, counterbalanced linkages that are adjusted using a mouth interface. A human interface to the robot will allow smooth operation as well as new programmable motions not obtainable with the non-actuated microscope stands. A robotically guided microscope will be able to move in a spherical motion allowing for quicker and easier focus about a point of interest. Future work in robotic augmentation must certainly allow tools to be manipulated. As a first step, we mount a biopsy holder on a parallel robot and discuss the compliance issues of the entire system.
Defining Quality Appearance Index Weights by Combining VR and CAT Technologies
Authors: Wickman Casper , Söderberg Rikard 
Published: November 2020

Abstract
As markets become increasingly competitive and customers more demanding, virtual verification has become an important tool for cutting costs and shortening lead-times. So far, the main focus area for Virtual Reality (VR) tools has been to extend and support concurrent engineering between manufacturing and design in early stages of the development process. Today, when a styling concept of a product is evaluated in an aesthetic manner, all models used are nominal. If the styling concept is evaluated with nominal models, variation aspects and design solutions that would greatly influence the overall quality appearance will not be discovered until the first test series are made. By using non-nominal models during the design process, important geometric aspects can be issued, and the need for physical test series can be reduced.
In the automotive industry, especially within body design, the relations between doors, hoods, fenders and other panels are critical. Today, the quality appearance (QA) of vehicles is judged by these relations.
This paper describes how virtual reality technique is used to define a weight system for different prominent areas of a product when evaluating the quality appearance with QA index. It will also discuss how combining traditional Computer Aided Tolerance (CAT) tools with modern virtual reality tools has the potential to enhance concurrency between styling and design and provide more powerful support for the geometry process in early phases. Traditional non-nominal verification can then already be conducted in the concept phase using digital models instead of physical ones.
In the paper, today’s geometry design process at an automotive company is described. An example of the rear end of a vehicle is used to illustrate how integrated CAT/VR tools can be used to support decision making when allocating weights fore the quality appearance index.
Planar Cable-Direct-Driven Robots: Part I — Kinematics and Statics
Authors: Williams Robert L. , Gallina Paolo 
Published: November 2020

Abstract
A hybrid parallel/serial manipulator architecture is introduced where the translational freedoms are provided by a cable-direct-driven robot (CDDR) and the rotational freedoms are provided by a serial wrist mechanism. The motivation behind this work is to improve the serious cable interference problem with existing CDDRs and to avoid configurations where negative cable tensions are required to exert general forces on the environment. Only the translational CDDR is considered in this paper; including kinematics and statics modeling, and determination of the statics workspace (the space wherein all possible Cartesian forces may be exerted with only positive cable tensions). Examples are presented to compare the planar 3-cable CDDR with one degree of actuation redundancy and the 4-cable CDDR with two degrees of actuation redundancy. It was found that the 4-cable case requires less cable tensions and thus less energy compared to the 3-cable case in performing the same simulated tasks.
Quad-Layer: Layered Quadrilateral Meshing of Narrow Two-Dimensional Domain by Bubble Packing and Chordal Axis Transformation
Authors: Yamakawa Soji , Shimada Kenji 
Published: November 2020

Abstract
This paper presents a new computational method for quadrilateral meshing of a thin, or narrow, two-dimensional domain. An output mesh of our method is well-shaped and either single-layered, multi-layered, or partially multi-layered. Element sizes can be uniform or graded. A high quality, layered quadrilateral mesh is often required for finite element analyses of a narrow two-dimensional domain with a large deformation such as the analysis of rubber deformation or sheet metal forming. Our method consists of two steps: (1) extraction of the skeleton of a given domain by the discrete chordal axis transformation, and (2) discretization of the chordal axis into a set of line segments and conversion of each of the line segments to a single quadrilateral element or multiple layers of quadrilateral elements. In both steps we use a physically-based computational method called bubble packing to discretize a curve into a set of line segments of specified sizes. Experiments show that the accuracy of a large-deformation FEM analysis can be significantly improved by using a well-shaped quadrilateral mesh created by the proposed method.
Position Analysis for a Class of Novel 3-DOF Translational Parallel Robot Mechanisms
Authors: Jin Qiong , Yang Ting-Li 
Published: November 2020

Abstract
A class of new 3-DOF parallel robot mechanisms is investigated. Closed-formed solutions are developed for both the forward and inverse kinematics. Compared with known 3-DOF parallel robot mechanisms, these mechanisms are not only simple in structure with fewer solutions for position analyses but also decoupled. The mechanism decouplity, which is related to the topological characteristics, dimensional parameters, kinematic joint types and the choice of input-joints, is very useful for real control and path planning of parallel robots.