bluuebunny/crossref_metadata_2025_split huggingface dataset:
Natural Frequencies of Parallelogrammic Plates Using Characteristic Orthogonal Polynomials in Rayleigh-Ritz Method
Authors: Lee L. T. , Pon W. F. 
Published: March 2021

Abstract
Natural frequencies of parallelogrammic plates are obtained by employing a set of beam characteristic orthogonal polynomials in the Rayleigh-Ritz method. The orthogonal polynomials are generalted by using a Gram-Schmidt process, after the first member is constructed so as to satisfy all the boundary conditions of the corresponding beam problems accompanying the plate problems. The strain energy functional and kinetic energy functionals are transformed from Cartesian coordinate system to a skew coordinate system. The natural frequencies obtained by using the orthogonal polynomial functions are compared with those obtained by other methods with all four edges clamped boundary conditions and greet agreements are found between them. The natural frequencies for parallelogrammic plates with other boundary conditions, such as four edges simply supported, clamped-free and simply supported-free, are also obtained. This method is considered as a better and accurate comprehensive treatment for this type of problems.
Building Three-Dimensional Computer Graphics Surface Models for Anatomy Education
Authors: Alciatore David G. , Miranda Rick 
Published: March 2021

Abstract
This paper describes an approach to generating three-dimensional computer graphics images of gross anatomical structures. These images are used in an interactive teaching aid which is currently being developed by the Colorado State University Vesalius Project. Key steps in the generation of these images include acquisition of appropriate anatomical data, the generation of parallel cross-sectional contours, and the creating of rendered surface models of the anatomy by triangulating between these contours. The algorithms involved with these steps are described and several resulting images are presented here. The interactive Hypertext educational system being developed around these images is also briefly discussed.
Modeling and Animation of Mechanical Systems
Authors: Wen Li , Bahr Behman 
Published: March 2021

Abstract
This paper presents a general purpose method for mechanism modeling and animation using 2-D or 3-D computer graphics technique. A simulation system based on this method enables designers or management to evaluate the motion performance of mechanisms in effective, flexible and inexpensive ways. This method is particularly well suited for uses in small manufacturing companies and educational institutes because of a little required expense. Examples, from a simple mechanism to a complex robot, will be given in the paper to prove that this method can be applied to a variety of applications.
Design of a Teleprogrammable Space Robotic Workcell for Unstructured Environments
Authors: Haule D. D. , Noorhosseini S. M. , Malowany A. S. 
Published: March 2021

Abstract
Many studies for the preliminary definition of a space teleoperated robotic devices are recently completed or under development. One example of such devices is the Flight Telerobotic Servicer (FTS) developed by NASA. These studies will assist astronauts in many ot the on- and off-board tasks of assembly, maintenance, servicing and inspection of the Space Station. This paper makes an assessment of the role that teleprogramming may have in furthering the automation capabilities of these devices by extending their capacity for growth and evolution. Relevant system engineering design issues are identified for its programming. An outline of teleprogramming environments is given which comprises of task planning and interpretation, simulation, specialized modules known as system agents and world model manager (influencing teleoperator decisions at a remote worksite).
A Space Robotic Workcell (SRW) is a collection of robots, sensors, and other equipment grouped in a cooperative environment to perform various complex tasks in space. Due to their distributed nature, the control and programming of SRWs is often a difficult task, for which dedicated space environments have to be designed. There is clearly established need to perform intervention tasks remotely in hazardous environments by machines. Examples of this need that are highly relevant to our discussion are space safety applications, space exploration and underwater structure maintenance and repair. In this paper we focus on Space Robotics & Automation. We have discussed a detailed study of autonomy versus teleoperation for intervention robots making a case for task level teleprogramming as a new emerging field in Telerobotics. A rationale for teleprogramming and its techniques, Expert Systems, SRW Subsystem Agents, SRW Task Planner and SRW Plan (for growth and evolution) are also covered in this paper.
New Design of Production Type CNC Hobbing Machine and its Gear Cutting Performance
Authors: Yagishita H. , Iizuka T. 
Published: March 2021

Abstract
A production type CNC hobbing machnie (a maximum module to be cut of 4 mm and a maximum workpiece diameter of 150 mm) has been newly designed and manufactured based on the concept that a special attention is paied to a rigidity and a thermal deformation of the machine structure as well as a rotational transmission mechanism to enable high speed drive. A maximum speed of hob shaft is 1200 rpm and a table speed is possible up to 160 rpm due to a full spur gear drive. A CNC controller used is a common type for a hobbing machine which has a 32 bit CPU and five axes are numerically controlled.
By paying a special attention to a torsional rigidity and a dynamic synchronous error between a hob and table, some tests are carried out. The results are compared with those of a full mechanical drive (FMD) hobbing machine.
It is ascertained that by high accuracy gear cutting tests spur gears are generated with a sufficiently high accuracy although a correction of synchronous error between a hob and table is not applied at all by NC software. Also, in a production shop, it is demonstrated that a lot of helical gears for automobile can be manufactured with high-productivity and high-accuracy, that is : a machining cycle time per one gear is shortened by shortening a loading and unloading time of gear blank; a lead error is maintained within a small deviation in spite of high feed rate; and a measured value by over roll method is maintained within a permitted limit during a continuously long machining operation, for example, all day-long.
The Stress Intensity Factor and Stiffness for a Cracked Spur Gear Tooth
Authors: Daniewicz S. R. , Collins J. A. , Houser Donald R. 
Published: March 2021

Abstract
The stiffness of a spur gear tooth mesh controls load sharing in an operating gearset as well as vibratory properties which further dictate fatigue resistance and gear noise. A spur gear mesh consisting of a pinion with a single cracked tooth and an uncracked gear is considered. Expressions are presented which allow the determination of stress intensity factors for small through face width fatigue cracks in spur gear teeth. Predictions of tooth pair stiffness for a cracked pinion tooth and uncracked gear tooth pair are made using an analytical model. The model is based on elastic energy methods and fracture mechanics principles. The model employs a conformal mapping technique from elasticity theory, often denoted in spur gear applications as the complex potential method, in which a gear tooth is mapped onto an elastic half-plane.
Tooth Cutting Method of Face Gear by Using CNC-Hobbing Machine
Authors: Ishii Harumi , Nagata Shigeyoshi 
Published: March 2021

Abstract
At present, the research on a gear having special tooth profile a using CNC hobbing machine have been making progress. However, the method of tooth cutting with using CNC hobbing machine is not used the full for an inherent ability of itself.
From the aforementioned view point, we have tried to test cut a face gear which is used an inherent latent ability of the CNC hobbing machine.
The unipurpose device has been manufactured for the purpose of improving aforementioned defects of conventional tooth cutting method. Then we have used a fly tool instead of an unipurpose hob cutter.
In general, a helicon gear has been cut by unipurpose hob cutter, giving vertical feed with using general type hobbing machine.
In this way, not only the tooth roughness decreases, but also processing time increases for the tooth cutting because the size of cut has to be made very small due to heavy cutting resistance.
In our research, the unipurpose device is attached to the CNC hobbing machine. Then a fly tool already located on the final point of full depth, translates along the tangential direction of the gear from an appointed position in the radial direction.
In this way, we can expect the cutting resistance to be reduced during manufacture. Also the tooth roughness will be improved.
Experimental Investigation of Flowrate Irregularity in Rotary Gear Pumps
Authors: Mimmi G. 
Published: March 2021

Abstract
In a previous paper the author proposed a method to reduce the periodic variation in flow rate for an external gear pump.
To verify the experimental results, a series of experimental tests on a expressly realized gear pump, was carried out. The pump was equipped with relieving grooves milled into the side plates.
The tests were done on a closed piping specifically realized and equipped for measuring the instantaneous flow rate of the fluid through a wedge-shaped hot film probe.
Computerized Analysis of Gear Meshing Based on Coordinate Measurement Data
Authors: Kin Vadim 
Published: March 2021

Abstract
A mathematical model is proposed for the reconstruction of gear tooth surface features based on the manufacturing process deviations measured with the help of a gear inspection (or coordinate measurement) machine. The model is extended to facilitate the computer simulation of meshing between the measured year and a theoretical master gear, or between two measured gears. This would allow one to predict the transmission errors and bearing contact which are otherwise only possible to investigate using the combination of single-flank testing and a time-consuming work-in and examination procedure.
The developed model is applied to the determination of tooth-to-tooth transmission errors of parallel-axis gears and can also be utilized to determine bearing contact and contact stresses and be useful in tooth surface fatigue life calculations.
How to Ensure Precise Analysis of Gear Surfaces and Diagnosis of Changes During Operation
Authors: Mengen D. , Weck M. 
Published: March 2021

Abstract
Constantly rising demands on power transmitting components such as gears have lead to special efforts in gear production processes. Aiming to increase the transmission of power while simultaneously maintaining as little volume as possible, the influence of microgeometry as well as fine surface form and structure are especially increasing in significance. These factors play an important role for the operational safety, lifespan and noise emission of gears. Accordingly, it has become increasingly important to be able to dependably describe and register the microstructural characteristics of surfaces, so that knowledge concerning fatigue mechanisms can be abstracted from the surface topography. For this, the process of stereophotogrammetry in combination with an efficient PC-program can provide extremely exact and informative data.
When the surface of mechanical components undergoes changes caused by fatigue mechanisms during operation, both micro- and macrostructural changes take place. In order to facilitate smooth and undisturbed operations, it is of utmost importance to be able to register developments of the condition of strongly stressed components during operation. This way, preventive maintenance measures can be enacted in advance. For this purpose, an effective monitoring and diagnosis instrument was developed, based mainly on structure borne noise analysis. The new diagnostic equipment is described an examples for effective monitoring of gears are given.
Comparative Fatigue Resistance of Fiber Reinforced Nylon 6 Gears
Authors: Crippa Giuseppe , Davoli Piermaria 
Published: March 2021

Abstract
The fatigue-life diagrams of injection-molded nylon 6 gears with different reinforcements are presented for various lubrication modes (dry, grease, splash oil lubrication) and for different meshing combinations (plastic/plastic and steel/plastic gears).
Tests have been carried out with a properly designed back-to-back rig; results are compared with previous experiments, performed with unreinforced nylon 6 gears. Tested gears have been 232 (70 in unreinforced nylon and 162 in differently filled polyamides). More than 700·106 cycles have been totalised.
From test data, and from the “matrix” of gear/pinion material combination, the capabilities of differently reinforced nylon 6 gears for fatigue and wear resistance have been outlined. These capabilities are the basis for a proper material selection in plastic gear design.
Comparison of Analysis and Experiment for Gearbox Noise
Authors: Oswald Fred B. , Seybert A. F. , Wu T. W. , Atherton William 
Published: March 2021

Abstract
Low-contact-ratio spur gears were tested in the NASA gear-noise rig to study the noise radiated from the top of the gearbox. Experimental results were compared with a NASA acoustics code to validate the code for predicting transmission noise.
The analytical code is based on the boundary element method (BEM) which models the gearbox top as a plate in an infinite baffle. Narrow-band vibration spectra measured at 63 nodes on the gearbox top were used to produce input data for the BEM model. The BEM code predicted the total sound power based on this measured vibration.
The measured sound power was obtained from an acoustic intensity scan taken near the surface of the gearbox at the same 63 nodes used for vibration measurements. Analytical and experimental results were compared at four different speeds for sound power at each of the narrow-band frequencies over the range of 400 to 3200 Hz. Results are also compared for the sound power level at meshing frequency plus three sideband pairs and at selected gearbox resonant frequencies. The difference between predicted and measured sound power is typically less than 3 dB with the predicted value generally less than the measured value.
Structural Configuration Examples of an Integrated Optimal Design Process
Authors: Chirehdast Mehran , Gea Hae Chang , Kikuchi Noboru , Papalambros Panos Y. 
Published: March 2021

Abstract
Structural optimization procedures usually start from a given design topology and vary proportions or boundary shapes of the design to achieve optimality of an objective under various constraints. This article presents examples of the application of a novel approach for initiating formal structural optimization at an earlier stage, where the design topology is rigorously generated. A three-phase design process is used. In Phase I, an optimal initial topology is created by a homogenization method as a gray-scale image. In Phase II, the image is transformed to a realizable design using computer vision techniques. In Phase III, the design is parameterized and treated in detail by conventional size and shape optimization techniques. Fully-automated procedures for optimization of two-dimensional solid structures are outlined, and several practical design problems for this type of structures are solved using the proposed procedure, including a crane hook and a bicycle frame.
An Approach to Zero Setup Panel Bending
Authors: Sturges Robert H. 
Published: March 2021

Abstract
An opportunity is found to reduce setup time in sheet metal panel bending tasks by deliberately leaving gaps between a segmented punch to allow passage of a bent flange or to adjust the distance between articulated die sections for reentrant bends. The effects of this practice on part appearance and dimension is addressed to assure part quality. The gap/thickness ratio is found to be an indicator of part geometry and subjective quality. A zero setup punch and die set is described for four-bend parts.
The Development of Virtual Concurrent Engineering and its Application to Stamped Products
Authors: Schmitz J. , Desa S. 
Published: March 2021

Abstract
It is well-known that so-called Concurrent Engineering is a desirable alternative to the largely sequential methods which tend to dominate most product development methods. However, the proper implementation of a concurrent engineering method is still relatively rare. In order to facilitate the development of a reliable concurrent engineering product development method, we start with a careful definition of concurrent engineering and, after an extensive study of all of product development, we propose three criteria which ideal concurrent engineering must satisfy. However, for labor, time, and overall cost considerations, ideal concurrent engineering is infeasible. Instead, we propose a computer-based environment which, by being constructed in accordance with the three criteria, attempts to approach ideal concurrent engineering. The result is the Virtual Concurrent Engineering method and computer implementation environment. This product development method and computer-based implementation system provide the detailed, structured information and data needed to optimally balance the product with respect to the main product development parameters (e.g., manufacturing costs, assembly, reliability). This important information includes re-design suggestions to improve the existing design. The designer can directly apply these re-design suggestions for design optimization, or he can use the results as input into a more complex design optimization or design parameterization function of his own. To demonstrate Virtual Concurrent Engineering, we use it to refine earlier work done by the authors in the Design for Producibility of stamped products. We discuss, in some detail, the results of applying Design for Producibility to complex stampings, including process plans and product producibility computations.
The Effective Use and Implementation of Computer-Aids for Life-Cycle Product Design
Authors: Ishii K. , Hornberger L. 
Published: March 2021

Abstract
This paper describes the key elements of usage and implementation of AI-based tools in a real product design environment. In the past several years, the authors have developed several intelligent programs to empower mechanical engineers in the product design of personal computers. The programs focused on plastic material selection, snap fit design, design for assembly, design for service, and design for injection molding. Engineers used the tools initially as training tools and then attempted to use them for real design tasks. Some programs received long term acceptance and usage by designers, while others did not. The metrics for successful development of the AI-based tools do not coincide with successful implementation and usage. This paper briefly describes each of the programs, takes a critical look at their long term utility, and seeks to extract the metrics behind successful tools in practical product design.
A Methodology for Compliant Mechanisms Design: Part II — Shooting Method and Application
Authors: Her I. , Midha A. , Salamon B. A. 
Published: March 2021

Abstract
A major task envisioned in the design of compliant mechanisms entails analyzing a large-deflection elastica for its deformed configuration, while being subjected to given displacement and force boundary conditions. The accuracy and convergence behavior of a chain calculation method for predicting nonlinear deflections in beam structures is examined. Three shooting methods are implemented to reduce boundary condition closure errors. These methods are evaluated by considering two example problems in compliant mechanisms.
Using Exact Gradients in Mechanism Design
Authors: Mariappan J. , Krishnamurty S. 
Published: March 2021

Abstract
This paper presents a new approach for mechanism synthesis using exact gradients in optimization. Currently, finite difference methods or similar approximate techniques are used to evaluate the derivatives that are necessary for performing mechanism optimization using gradient-based methods. Typical mechanism synthesis problems involve highly nonlinear functional relationship, and the use of finite difference methods in such problems often leads to an excessive number of function evaluations, algorithm failures, and inaccurate results. Instead, an alternative approach using exact gradients will completely eliminate all of the above problems, and will result in a faster and efficient convergence. This paper also discusses the identification of an appropriate optimization method, namely, the generalized reduced gradient method for mechanisms synthesis based on its good convergence properties, reliability, intermediate feasibility, and efficiency. Numerical examples are included to illustrate the advantages of using exact gradients and the results are discussed.
Optimal Tolerance Allocation Over Multiple Manufacturing Alternatives
Authors: Cagan Jonathan , Kurfess Thomas R. 
Published: March 2021

Abstract
We introduce a methodology for concurrent design that considers the allocation of tolerances and manufacturing processes for minimum cost. Cost is approximated as a hyperbolic function over tolerance, and worst-case stack-up tolerance is assumed. Two simulated annealing techniques are introduced to solve the optimization problem. The first assumes independent, unordered, manufacturing processes and uses a Monte-Carlo simulation; the second assumes well known individual process cost functions which can be manipulated to create a single continuous function of cost versus tolerance with discontinuous derivatives solved with a continuous simulated annealing algorithm. An example utilizing a system of friction wheels over the manufacturing processes of turning, grinding, and saw cutting bar stock demonstrates excellent results.
A Symmetrical Coordinate Frame on the Hexagonal Grid for Computer Graphics and Vision
Authors: Her I. 
Published: March 2021

Abstract
This note is concerned with the hexagonal tessellation of picture elements used in computer graphics and computer vision systems. The purpose is to propose a symmetrical hexagonal coordinate frame to replace the existing oblique coordinate system. In the proposed symmetrical coordinate frame, spatial properties of the hexagonal grid such as distance functions are better represented.
Blending and Joining Using Cyclides
Authors: Srinivas Y. L. , Dutta Debasish 
Published: March 2021

Abstract
We consider the use of cyclides in geometric modeling. These are algebraic surfaces of degree four with interesting properties such as rational parametric forms and closure under offsets. The incorporation of cyclides as primitives in solid modellers will increase their geometric coverage. In this paper, we describe the cyclide and discuss two applications of its use in computer aided design — modeling blending surfaces and the automatic joining of pipes. Implemented examples are also included.
Boundary Surface Recovery From Skeleton Elements: Part I — Skeleton Curves
Authors: Gelston Sean M. , Dutta Debasish 
Published: March 2021

Abstract
Skeleton curves and surfaces have many applications in computer aided design and analysis. Construction of skeletons is an active area of research. We consider the inverse problem that of recovering boundary surfaces from given skeleton elements. The skeleton of any 3D object will, in general, consist of curves and surfaces. Therefore, any boundary reconstruction algorithm must systematically process the surfaces generated by the skeletal curves and the skeletal surfaces. In this paper (Part I) we present algorithms for reconstructing boundary surfaces corresponding to skeletal curves. Implemented examples are also included. In a companion paper (Part II) we consider skeletal elements that are surfaces.