bluuebunny/crossref_metadata_2025_split huggingface dataset:
Learning From Experience of Peers: An Empirical Study of Knowledge Sharing in a Product Design Community
Authors: Liang Tao , Leifer Larry J. 
Published: December 2020

Abstract
In this paper, we describe usage patterns of a design information database observed from four years of data, and discuss issues of learning through social and technology mediated interactions in a product design community. From the period of 1994 to 1999, an increasing amount of the design information in a project-based course at Stanford University has been captured in electronic format. This design information consists of design notes, drawings, reports, slide presentations, emails, vendor references, and even, in some cases, summaries of phone conversations, meeting minutes, and the like. The large corpus of captured information was made available to the project teams during each academic year on the assumption that one would be able to achieve better performance by building on and learning from experiences of peers. Because the data was all made available over a webserver, we were able to collect information on access to it We have thus had a chance to learn from studying the usage of a large body of captured design information. Preliminary analysis on the first two years of data was reported in DETC conference in 1998 (Liang, Cannon et al. 1998). Results from our current analysis show some interesting patterns of file utilization. Those patterns includes a surprising high ratio of access to process-related files, as opposed to product-related files; a temporal access pattern that closely matches project deliverables and milestones; and, an increased correlation between database usage and team-based performance over time.
The results from quantitative data analysis are augmented with qualitative user interviews. When interviewed, all engineers agreed that there could be a lot of benefits from learning from peer experiences. Nevertheless, physical and psychological barriers often prevent one from doing so. Physical barriers include distance, time, and organizational distance. Some psychological barriers include the perceived value of the archived information, and perceived effort of finding useful information. These pragmatic organizational learning issues arise from the fact that the teams were working on diverse projects and are all pressured by time and resources. We hypothesize that these real-world constraints of time and resources prohibited many learning opportunities to occur which would otherwise have been very productive and effective. This tension between learning and working is the backdrop of this learning experiment. We suggest that the patterns reported in this paper will be typical of a small product design consulting firm that has many fast-paced projects running in parallel.
State Library Materials Handling System Design: Part I
Authors: Derby Stephen , Simon Matthew P. , Puffer Raymond H. , Allen Mark A. , Shone Tristan M. , Winston Jeremy B. , Judd Van 
Published: December 2020

Abstract
This paper (part one of two) addresses the investigative efforts of the Center for Automation Technologies (CAT), Rensselaer Polytechnic Institute, into the requirements and processes of the New York State Talking Book and Braille Library (TBBL), and the describes the first several module concepts in the automation system designed to assist the TBBL staff in the processing of “talking books” (books on cassette). Part two discusses the remaining modules, system simulations, and conclusions.
The primary purposes for this modular system are 1. To assist the TBBL in meeting increased throughput demands and 2. To reduce work-related injury claims. The modules are designed to work individually (as to allow the possibility of similar libraries in other states purchasing modules as desired), and facilitate incremental implementation toward a complete system (for maximized benefit).
In this paper, the modules discussed are the BMC unloader (for which a patent application has been filed), the sorting and singulating module, the case orientation and latch opening module, a possible buffer module, and the automation-assisted rewind and inspection module.
Design of Angular Snap-Fits for Positive Interference Assembly
Authors: Sodhi Raj S. , Das Sanchoy 
Published: December 2020

Abstract
This article introduces a new design for a cantilever type snap-fit fastener. This new design is configured to provide a positive interference between the mating parts even in the assembled position. The legs are therefore not in a relaxed position at the end of assembly. This results in higher levels of alignment quality and part fit in a completed assembly. The positive interference is achieved by the use of angular legs as opposed to orthogonal legs in a traditional snap-fit. Issues of material strength, fastener geometry, part stiffness, attachment strategy and manufacturability are addressed in the paper.
Automated Initial-Population Generation for Genetic-Algorithm-Based Assembly Planning
Authors: Smith Gregory C. , Chen Shiang-Fong 
Published: December 2020

Abstract
Genetic algorithms show particular promise for automated assembly planning. As a result, several recent research reports present genetic-algorithm-based mechanical-product assembly planners. However, genetic-algorithm-based assembly planners require an initial assembly-sequence population, and search efficiency greatly depends upon input-population quality. State-of-the-art genetic-algorithm-based assembly planners use one of two techniques for generating an initial assembly-sequence population: use a user-supplied assembly-sequence set or use a randomly generated assembly-sequence set. Generating a user-supplied initial population requires a substantial amount of manpower. Using a randomly generated initial population reduces search efficiency. As a result, we propose an algorithm for automatically generating an initial assembly-sequence population. Our algorithm calculates component assembly complexity and uses both component assembly complexity and component connectivity to automatically generate a valid assembly-sequence population. Using automatically generated initial populations, we achieve search efficiencies comparable to search efficiencies achieved when using user-supplied initial assembly-sequence populations, while eliminating manpower required to generate user-supplied assembly sequences.
Assembly Configurations of Planar Multi-Loop Mechanisms With Kinematic Limitations
Authors: Foster David E. , Cipra Raymond J. 
Published: December 2020

Abstract
This paper examines the problem of identifying the assembly configurations (ACs), also called circuits, of planar multi-loop mechanisms with kinematic limitations, such as joint limits, link interference, collision with stationary obstacles, and workspace limitations. First, a method is given to describe numerically the satisfaction or violation of these kinematic limitations, and then this is applied to find the ACs of mechanisms with kinematic limitations. The method is valid for mechanisms with one or two degrees of freedom, and is illustrated with two examples.
Finite-State-Machine Representations for Mechanisms and Chains With Variable Topologies
Authors: Yan Hong-Sen , Liu Nien-Te 
Published: December 2020

Abstract
This paper provides a novel representation for the topological structures of mechanisms and chains with variable topologies. The concept is finite state machines. Graphs are traditional representations of mechanism topologies and have the advantages of easily observing. Finite state machine is proposed for expressing the changes of input links and operating stages. The double-dwell slider-crank mechanism is applied as an example to illustrate the proposed representations. These representations are useful for analyzing the characteristics of topology structures of mechanisms and chains with variable topologies. And, the result of this work can be extended for synthesizing mechanisms and chains with variable topologies.
Solving the Kinematics of Planar Mechanisms by Dixon Determinant and a Complex-Plane Formulation
Authors: Wampler Charles W. 
Published: December 2020

Abstract
This paper presents a general method for the analysis of any planar mechanism consisting of rigid links connected by revolute and slider joints. The method combines the complex plane formulation of Wampler (1999) with the Dixon determinant procedure of Nielsen and Roth (1999). The result is simple to derive and implement, so in addition to providing numerical solutions, the approach facilitates analytical explorations. The procedure leads to a generalized eigenvalue problem of minimal size. Both input/output problems and the derivation of tracing curve equations are addessed.
A Method for Representing the Configuration, and Analyzing the Motion of Complex Cable-Pulley Systems
Authors: Hong Dennis W. , Cipra Raymond J. 
Published: December 2020

Abstract
In this paper a systematic way of representing complex cable-pulley mechanism configurations and a method to analyze and synthesize the motion of these cable-pulley devices is presented. The cable-pulley system model that is being considered is composed of three basic elements which are pulleys, blocks, and cables. A configuration table is used to identify the constraint equations by systematically defining the connections between the cables, pulleys, and blocks. The basic strategy is to use the constraint equations to generate the relationship between each variable and a subset of the variables identified as the inputs. The number of input variables is equal to the total number of variables minus the number of independent constraints. This choosing of the set of inputs is done in conjunction with a row reduction process on the system of constraint equations which identifies the number of inputs and ultimately generates the relationships of each variable to the input(s). Examples are given to illustrate the procedure.
Configuration Estimation of Gough-Stewart Platforms Using Extended Kalman Filtering
Authors: Fasse Ernest D. , Wavering Albert J. 
Published: December 2020

Abstract
This paper develops extended Kalman filtering algorithms for a generic Gough-Stewart platform assuming realistically available sensors such as length sensors, rate gyroscopes, and accelerometers. The basic idea is to extend existing methods for satellite attitude estimation. The nondeterministic methods are meant to be a practical alternative to existing iterative, deterministic methods for real-time estimation of platform configuration.
A Study of Vibration in Caliper-Disc Brake Systems With Surface Roughness Effects: Part B — Inclusion of Surface Roughness Effects in the Equations of Motion and Results
Authors: Meinhardt Glenn , Farhang Kambiz , Abdo Jamil 
Published: December 2020

Abstract
Vibration of mechanical systems with friction depends on the physical characteristics of the frictional contact. The elastic characteristics are developed in a companion paper, wherein the results show the surface roughness manifested through nonlinear contact stiffnesses. This paper, the second of two companion papers, incorporates the elastic characteristics of contact between the pad surfaces and the rotor in a vibration model of an automotive caliper-disc brake system. The elastic representation of contact, in the form of polynomial functions of the relative pad/rotor displacements, are used to account for the effect of surface roughness on the vibration response of a caliper-disc brake system. The results indicate a range of frequencies due to the roughness induced stiffness nonlinearities.
Fatigue Testing Machines for Tensile and Bending Loaded Bolt Connections Using Sympathetic Vibration
Authors: Alt Attila , Tegel Oliver 
Published: December 2020

Abstract
In this paper previous tension and bending fatigue testing machines for bolt connections are presented. Their weak points are discussed, in order to show the difficulty of machine load and the demands of a load distribution in the bolt connection similar to the operating state, a measurement of stresses on the bolt and an economical actuation.
A new principle using the sympathetic vibration of a frame for applying the load is presented in comparison. It can be employed for tensile and bending load. The barrel of the bolt remains accessible for direct measurement of it’s strains. Formulas for the dimensioning of the frames considering their natural frequency and the tensile/bending load combination of the bolt connection are derived using the mechanics of elastic beams. The testing machines and their details are described.
A Systematic Method for Kinematics Synthesis of High-Speed Mechanisms With Optimally Integrated Smart Materials
Authors: Rastegar J. , Yuan L. 
Published: December 2020

Abstract
A systematic method is presented for kinematics synthesis of high-speed mechanisms with optimally integrated smart materials based actuators for the purpose of modifying the output link motion. As an example, the method is applied to a four-bar linkage mechanism that is synthesized for function generation to eliminate the high harmonic component of the output link motion. For mechanisms with rigid links, the high harmonic motions are generated due to the nonlinearity of the kinematics of their closed-loop chains. By eliminating the high harmonic component of the output motion, the potential vibrational excitation that the mechanism can impart on the overall system and its own structure is greatly reduced. The resulting system should therefore be capable of operating at higher speeds with increased precision. A numerical example is provided together with a discussion of the application of the method to other mechanism synthesis problems and some related topics of interest.
A Configurationally Adjustable Planar Stewart Platform Machining Center With Feasible and Optimum Placement of Workspace Relative to Toolpath
Authors: du Plessis L. J. , Snyman J. A. , Smit W. J. 
Published: December 2020

Abstract
This paper presents a new integrated configurational design system that allows for the feasible and optimum placement of the workspace of an adjustable planar parallel manipulator, relative to a specified machine toolpath. The basic design of the manipulator is such that the positioning and relative size of the workspace may be varied by means of the adjustable placement of the revolute joints. For a given specified toolpath an integrated geometry optimizer prescribes a manipulator configuration which, not only ensures feasibility, but also enhances performance through the minimization of an objective function related to the required actuator forces, subject to physical constraints.
The availability of the combination, of a physically adjustable platform coupled to a software geometry optimizer, is essential for the practical application of a planar parallel platform as a machining device for toolpaths of varied specifications. Here the proposed system is applied and tested through its application to a planar Stewart platform demonstrator with full adjustment capability. The platform serves to demonstrate the optimum machining motion obtained through the integrated design system. This system will later be incorporated in a more robustly constructed and fully equipped prototype platform for practical machining.
An Analytical Design for CaPaMan With Prescribed Position and Orientation
Authors: Ceccarelli Marco , Ottaviano Erika 
Published: December 2020

Abstract
A desired workspace can be described by a set of points, which prescribe desired positions and orientations of the movable plate of a parallel manipulator. In this paper we have proposed a formulation for designing CaPaMan (Cassino Parallel Manipulator) when position and orientation of the movable plate are prescribed. A numerical procedure has been deduced to solve design parameters by using analytical formulation of Direct and Inverse Kinematics for CaPaMan architecture.
Cartesian Control for the Inertial Measurement Unit Calibration Platform
Authors: Hall John J. , Williams Robert L. , van Graas Frank 
Published: December 2020

Abstract
The Department of Mechanical Engineering and the Avionics Engineering Center at Ohio University are developing an electromechanical system for the calibration of an inertial measurement unit (IMU) using global positioning system (GPS) antennas. The GPS antennas and IMU are mounted to a common platform to be oriented in the angular roll, pitch, and yaw motions. Vertical motion is also included to test the systems in a vibrational manner. A four-dof system based on the parallel Carpal Wrist is under development for this task. High-accuracy positioning is not required from the platform since the GPS technology provides absolute positioning for the IMU calibration process.
The Compound Union Theory and Method of Type Synthesis of Geared Linkage Kinematic Chains
Authors: Liu Chuan-He , Yang Ting-Li 
Published: December 2020

Abstract
The compound union theory and method of type synthesis of geared linkage kinematic chains is developed in this paper. The theory includes the new concepts, such as the basic geared kinematic chain, the compound union and the type code etc., the new constitution principle of geared linkage kinematic chains and four new theorems that are essential for type synthesis of geared linkage kinematic chains. One typical example and its results of the type synthesis are also given. It is proved that the compound union theory and method is systematic, strict, simple, practical and efficient.
Omni-Directional Mobility Using Active Split Offset Castors
Authors: Yu Haoyong , Dubowsky Steven , Skwersky Adam 
Published: December 2020

Abstract
A new concept for omni-directional platform and vehicle design using active split offset castors is presented. An active split offset castor (ASOC) unit consists of two coaxial conventional wheels driven independently and connected to the platform chassis by a link. The kinematics and characteristics of the ASOC are analyzed and compared with conventional active castors and steered wheels. The concept of building omni-directional platforms and vehicles using the ASOC is presented and their design and control are discussed. Experimental results from a prototype omni-directional platform are presented, which demonstrate the feasibility of the concept.
3-D Finite Element Analysis of Long Fiber Reinforced Composite Spur Gears
Authors: Alagöz Çağdaş , Arıkan M. A. Sahir , Bilir Ö. Gündüz , Parnas Levend 
Published: December 2020

Abstract
A method and a computer program are developed for 3-D finite element analysis of long fiber reinforced composite spur gears, in which long fibers are arranged along tooth profiles. For such a structure, the gear is composed of two regions; namely the long fiber reinforced and the chopped fiber reinforced regions.
Pre and post-processing modules of the program for the finite element analysis are written in Borland Delphi Pascal 3.0®. ABAQUS® is used for finite element analysis. Main inputs for the pre-processing module of the program are, information on basic gear geometry, gear drive data, material properties and long fiber reinforcement geometry. Finite element meshes are automatically generated and mesh information with other required data are written to a file in the input-file-format of ABAQUS®. Stresses are read from the output file of ABAQUS® by the post-processing module, and color-coded drawings for various stresses and failure index are displayed. For the long fiber reinforced region, failure indexes are calculated by using the tensor polynomial failure criterion.
Effects of reinforcing thickness and location of long fibers on gear strength are investigated. Stresses and failure index are calculated for different materials and fiber volume ratios.
Sensitivity of Wildhaber-Novikov Gears to Center Distance Variations
Authors: Esposito Antonio , Belfiore Nicola P. 
Published: December 2020

Abstract
In this paper, the sensitivity of the pressure angle to the variation of the center distance is determined analytically for a whole class of helical gears. The results are then applied to the case of Wildhaber-Novikov gears, showing that these gears are highly sensitive to center distance changes, which easily cause edge contact to occur between the teeth.
Effect of Internal Gear Flexibility on the Quasi-Static Behavior of a Planetary Gear Set
Authors: Kahraman Ahmet , Vijayakar Sandeep 
Published: December 2020

Abstract
Effect of flexibility of an internal gear on the quasi-static behavior of a planetary gear set is investigated. A state-of-the-art FEM/semi-analytical nonlinear contact mechanics formulation is employed to model a typical automotive automatic transmission planetary unit. The model considers each gear as deformable bodies, and meshes them to predict loads, stresses and deformations of the gears. Actual support and spline conditions are included in the model. The rim thickness of the internal gear is varied relative to the tooth height and gear deflections and bending stresses are quantified as a function of rim thickness. Influence of rim thickness on the load sharing amongst the planets is also investigated with and without floating sun gear condition. The results are discussed in detail and guidelines regarding the design of a planetary internal gear are presented.
Research of Gears With Progressive Path of Contact
Authors: Hlebanja Gorazd , Hlebanja Jože , Okorn Ivan 
Published: December 2020

Abstract
In recent years we have conducted research of new gears with a progressively curved path of contact as illustrated in Figure 1 below. We also tried to prove features anticipated for these gears. Thus our research focused on durability of this type of gears regarding to pitting and scuffing. We compared them to the involute gears of the same dimensions. We discovered a higher load capacity of tooth flanks of the new gears compared to the involute gears in case of scuffing. Both types of gears showed approximately the same load capacity against pitting if a transverse operating angle was the same in both cases. It has been proved that the new gears had better efficiency and considerable lower wear. We tested gear pairs made of through hardened steel and those nitrided after machining.
Our paper will discuss some results of the research work on the new type of gears for which we believe they will find their way to the practice.
Viscoelastic Tooth Root Stress Analysis on Fiber Reinforced Thermoplastic Poly-Imide (TPI) Gears
Authors: Donghui Gong , Moriwaki Ichiro , Saito Kenji 
Published: December 2020

Abstract
Although thermoplastic poly-imide (TPI) gears do not have sufficient strength for power transmission, carbon fiber reinforcement greatly improves the strength of TPI gears. Previous experimental research showed that although standard specimens made from carbon fiber reinforced (CFR) TPI has 2.4 times strength in static bending than specimens made from natural TPI, gears made from CFR-TPI yields bending fatigue strength about 10 times greater than gears made from natural TPI. The present paper explains this phenomenon using viscoelastic tooth root stress analysis. The experiments indicated that the natural TPI gears showed much larger viscoelasticity than the CFR-TPI gears. Thus, tooth root stresses were calculated for cases of large and small viscosity moduli. These calculations showed tooth root stress increased with the increase in the viscosity modulus. Also, viscoelasticity may induce heat due to hysteresis loss, and this heat should reduce gear durability. The increase in tooth root stress and the heat due to hysteresis loss must make the durability of the natural TPI gears very small. Therefore, the CFR-TPI can yield much more durable gears than the natural TPI.