bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Hybrid Computational Model for Mechanical Design
Authors: Rangaraj B. S. , Thompson J. G. , Krishnaswami P. 
Published: March 2021

Abstract
Engineering design is a complex activity which involves knowledge application and creativity to generate and explore the space of possible designs. Since engineering knowledge is heterogeneous in terms of the kinds of problems it encompasses and the methods used to solve them, an hybrid computational model for design, in particular for mechanical design, is proposed in this paper.
The proposed model called the Design Frame (DF) is based on the iterative application of a generalized solution strategy. A given design problem is recursively decomposed into smaller subproblems until the subproblems can be directly solved. Repeated application of decomposition produces a natural design hierarchy. A Rule-based Controller (RBC) can call one or more decision modules and a subproblem DF during the iterative process. The RBC along with the decision modules gives the model the capability to handle both qualitative and quantitative knowledge and data. The DF’s for all subproblems have the same structure as the top-level and apply the same solution strategy. Domain dependent knowledge can be added by the user to the existing modules or new modules can be supplied by the user.
A brief discussion on a prototype implementation of the DF model has been included.
Quality Improvement of the Product Development Process Using Performance Metrics
Authors: Johnson Timothy L. , Dooley Kevin J. 
Published: March 2021

Abstract
As the international marketplace has opened up, companies are finding that both their competition and customer bases have expanded greatly. In addition, the rate of technological growth continues to accelerate, leaving many products out-dated in a relatively short time. Companies must meet both of these challenges in order to remain competitive. This requires an efficient product development process, one that is flexible and able to meet its customers’ diverse requirements in a timely manner. This paper examines product development and, in particular, looks at the use of metrics in evaluation, control, and improvement of the product development process. Specifically, it is shown how metrics can be used to evaluate the progress, performance, and quality of development activities. Issues involving data collection are described, and the paper concludes with a discussion of organizational issues and a case study.
Experiment and Computer Modelling of the Filling Flows in Pressure Die Casting
Authors: Hu J. , Ramlingam S. , Meyerson G. , Eckert E. R. G. , Goldstein R. J. 
Published: March 2021

Abstract
Until recently, computer simulation of filling flows in die casting have been focused on the determination of the free surfaces of injected liquid and has had difficulties to relate the flows with the formation of casting porosity. Flow visualization in scaled experiments indicates that the liquid has very complicated surfaces and that, in many cases, the surfaces break up and create a mixture zone with liquid droplets and air. This is especially true in pressure die casting where liquid metal is injected at a speed in order of 100 m/s and at a pressure up to 100 atm. The Reynolds number in the process could be above 105 and the Weber number above 102. Surface tension is far from sufficiently strong to sustain disturbance growth due to various instabilities. It is hard to keep the liquid as a separate continuous phase.
Based on flow visualization experiments, a mathematical model is proposed as an alternative and effective simplification to the traditional tracing methods. Instead of determining the continuous free surfaces, the model tries to predict distributions of mass fraction of the injected liquid by solving a partial differential equation of mass transport together with the Navier-Stokes equations. Appropriate unsteady schemes of a finite difference analysis have been developed and are described in the paper. Results with an uniform straight injection into a die cavity are presented, which have re-created the filling patterns of the flows in experiments.
Particle Transport in CVD and Diffusion Processes
Authors: Busnaina Ahmed , Zhu Xiaoying , Zheng Xiaowei 
Published: March 2021

Abstract
Particle transport and deposition in a CVD chamber and a horizontal diffusion furnace are studied. Mean flow and thermal fields are simulated using GENFLOW, which is a general computer code for fluid flow and heat transfer computations. Trajectories of aerosol particles in the chamber and the furnace are evaluated by solving the corresponding Lagrangian equation of motion that includes effects of temperature, drag, gravity, Brownian motion and turbulence fluctuations generated during pumping or venting. Aerosol particles are released at the gas inlet and are carried towards the wafers with sizes of 0.05–1.0 micron in the CVD chamber and 1.0 micron in the diffusion furnace. Depositions of particles on the wafer, wafer temperature and inlet turbulence intensity are evaluated.
Optimization of Noise Level Reduction by Truncated Model Coupled Structural-Acoustic Sensitivity Analysis
Authors: Kozukue Wakae , Pal Chinmoy , Hagiwara Ichiro 
Published: March 2021

Abstract
A method for evaluating simultaneous optimization of a number of strucural/acoustic responses of a coupled strutural-acoustic problem is presented in this paper. Different and mutually conflicting criteria, the strucural response and sound pressure level etc., are taken as objective functions. The general inverse problem is solved to find out the required minimum change of plate thickness which is taken as design variable to satisfy/achieve the target values of the objective functions.
Thermal Residual Stress Analysis for In-Situ and Post-Consolidated Composite Rings
Authors: Tzeng Jerome T. , Pipes R. Byron 
Published: March 2021

Abstract
The thermoelastic response of a thick multilayered composite ring subjected to the sequential addition of layers which undergo instantaneous temperature change and corresponding thermal deformation is modeled. The analysis considers ply-by-ply variations of material properties and fiber orientations. The resulting residual stress field is examined as a function of important physical parameters such as ring geometry, layer material properties, fiber orientation, and layer sequence.
Penetration by Long Rods
Authors: Gillis Peter P. , House Joel W. , Jones S. E. 
Published: March 2021

Abstract
This paper relates to the penetration of large, massive targets by long rods where target penetration is accompanied by rod erosion. A principal criticism of previous analyses of this problem by the present authors was the use of post test measurements to furnish input information for calculations. Thus, the analyses had no truly predictive capability. In particular, the profile hole diameter of the experimental target crater was previously employed as a measure of mushroom strain at the penetrator tip. Because this strain value has a significant effect on calculated penetration depths, it is very important to be able to predict it rather than measure it. In this paper a recent result from the analysis of the initial transient penetration phase is used to estimate mushroom strain. This result is incorporated into the previous steady-state analysis to make it predictive. This new theory is the basis for calculations that are compared with previously published experimental results. The degree of agreement is really quite good for a procedure in which there are no adjustable parameters. In any case, the new computational method is certainly a substantial improvement over the previous reliance on post impact information.
Applications of Electronic Spreadsheets in Mechanical Engineering
Authors: Khosrowjerdi Mohammad 
Published: March 2021

Abstract
Electronic spreadsheet packages which were originally developed to create budget and do financial computations can now be used to perform innovative computer-based analyses. As these packages make increasing inroads into engineering profession, variety of new and innovative professional and instructional applications are being emerged. No longer confined to accountants and business people — electronic spreadsheet utilizations in engineering ranging from sensitivity (parametric) analysis to optimization are becoming more popular. Recently, those engineers who have recognized the usefulness and power of newly added features to these programs have started exploring the possibility of using these packages as a decision-making tool in the area of computer-aided engineering. This growing use of spreadsheets stems from their ability to perform repetitive sophisticated calculations on real time and the availability of built in procedures desirable for technical presentation.
To enhance their teaching and expose students to the applications of electronic spreadsheets, some engineering educators have started integrating these productivity tools into their courses. The computational power of new generation of personal computers in conjunction with ever increasing graphics and advanced mathematics capabilities of spreadsheets can now be employed to perform parametric or what-if analyses.
It is the intent of this paper to demonstrate the use of spreadsheet packages to solve a wide spectrum of problems in mechanical engineering. The case studies used in this paper are taken directly or in some cases with slight modifications from undergraduate text books. The Borland Quattro Pro spreadsheet package version 3 has been utilized to perform spreadsheet-based engineering analyses.
Laser Holographic Measurement of Tooth Flank Form of Cylindrical Involute Gear: Part 2 — For Helical Gear Tooth
Authors: Fujio H. , Kubo A. , Tochimoto S. , Hanaki H. , Saitoh S. , Suzuki M. 
Published: March 2021

Abstract
The interferometry using laser holography is applied to measure the form deviation of tooth flank of involute helical gears. One problem of this method is that the increase of helix angle reduces the region of the flank to which the laser beam can irradiate at a same time. To solve this problem, following method is developed: The objective tooth flank is divided into some regions, and the interferometry measurement is worked out for each region. The measured values for the form deviation of each region of the tooth flank are transformed to the values on the plane of action of this gear. These values for each region of the tooth flank are then concatenated successively until they result the curved surface for the form deviation of the whole tooth flank of the helical gear. The error surface of the tooth flank of helical gear obtained by this procedure is compared with that of conventional measuring method using contacting stylus.
A Research on Bevel Gear Hobbing
Authors: Nagata Shigeyoshi , Komori Tsutomu 
Published: March 2021

Abstract
At present, hob cutters have mainly been used for the tooth cutting of gears. The each blades of the hob cutter have generally been designed with the same module size, therefore, it is not possible to cut gears of another module size using the aforementioned hob cutter. In our research, from the above viewpoint we have through theoretical analysis of a new hob cutter, tried to design a module hob cutter which is able to cut gears of several module sizes during rough cutting. Hereinafter, we are to call this new hob cutter “Variable Module Hob Cutter (= VMHC)”.
This “VMHC” is not uniform in the whole length of hob cutter. It is designed so that the module size is made to vary in accordance with axial direction. With this “VMHC”, not only is it possible for us to cut the tooth profile of gear in any variety of module sizes, but also it is expected to be very suitable for cutting bevel gears by using general type hobbing machine. Most of bevel gears are manufactured by a unipurpose machine tool. Bevel gears, however, are able to be manufactured easily even by using the general type hobbing machine by applying the conventional method of tooth cutting and this hob cutter. The bevel gears have been difficult to manufacture by the conventional hob cutter.
However, we will be able to expect to get “VMHC” easily through use of CNC technology.
Dynamic Analysis of a Multi-Mesh Helical Gear Train
Authors: Kahraman Ahmet 
Published: March 2021

Abstract
In this paper, the dynamic behavior of a multi-mesh helical gear train is studied. The gear train consists of three helical gears, with one of the gears in mesh with the other two. An 18-degree-of-freedom dynamic model which includes transverse, torsional, axial and rotational (rocking) motions of the flexibly mounted gears is developed. Two different loading conditions are identified. For case I, the system is driven by the gear in the middle, and for case II, the system is driven by one of the gears at either end of the gear train. Gear mesh phases under each loading condition are determined. The natural modes are predicted, and effects of the helix angle and the loading condition on the natural modes are explained. The forced response, which includes dynamic mesh and bearing forces, due to the static transmission error excitation is found. Effects of loading conditions and asymmetric positioning on the response are also explored. The results suggest that the dynamic forces are lower if the number of teeth of the gear in the middle is (i) an odd number for case I type loading, and (ii) an even number for case II type loading.
Fuzzy Optimization Design on Worm Drive
Authors: Qun Lin , Wenhui Zhong , Meijuan Wu 
Published: March 2021

Abstract
A mathematical model of multi-objective fuzzy optimization design is described in this paper, where the volume of corona dentis and the efficiency of transmission were chosen as objective functions. The optimal confidence level λ* and the augmentation coefficient β were specified by using two-level fuzzy synthetic evaluation method. As a consequence, the fuzzy optimization design problem was converted into non-fuzzy optimization design problem which could be solved with the mixed discrete optimization technique. The numerical result would be of some reference value to the design of worm drive.
Transmission Error Characteristics of a Stepping Motor Drive Timing Belt System for a Fixed and an Automatic Tensioner
Authors: Kim Hyunsoo , Wee Hyuk 
Published: March 2021

Abstract
The transmission error characteristics of a stepping motor drive timing belt system are investigated theoretically and experimentally for the fixed and the automatic tensioner. It is found that the amplitude of the transmission error θe due to the pulley eccentricity and θm due to the stepping motor torque variation decrease as the belt tension increases and the applied torque load increases. Also, θe can be reduced by using the automatic tensioner, while θm shows almost same magnitude for both tensioners. The theoretical results based on the bondgraph model are in good accordance with the experimental results.
Automated Optimal Shape Design System of Planar Link Mechanisms Using an Object-Oriented Modeling Method
Authors: Fujita Kikuo , Akagi Shinsuke , Tsujimoto Kazunori 
Published: March 2021

Abstract
An optimal shape design system for planar link mechanisms is developed using an object-oriented modeling technique. In the formulation of the shape design problem, the driving forces required for the motion of the follower are considered as objective functions to be minimized, and relationships on kinematics and statics are investigated as constraints. The process of mathematically formulating the problem is so complicated that the usual optimization techniques are not effective enough to support the shape design. In our system, link mechanisms are represented using an object-oriented modeling technique based on their graph representation. Based on the representation, the formulation for optimal design is automatically carried out. The system has effective user-interface functions for setting initial shapes of mechanisms and showing results of optimization calculation. Finally, it is applied to the optimal shape design of a power shovel in order to check its validity and effectiveness.
An Introduction to Mechanical Advantage in Compliant Mechanisms
Authors: Salamon B. A. , Midha A. 
Published: March 2021

Abstract
An energy approach is utilized to determine mechanical advantage in compliant mechanisms by duly accounting for lost work due to deformation. Three mechanical advantage types are then defined which examine the isolated influences of various parameters. Finally, a case study is investigated to exemplify these definitions and demonstrate resulting trends in mechanical advantage.
B-Rep Feature Extraction via Primitive Tracking
Authors: Ganter M. A. 
Published: March 2021

Abstract
A modification of the B-Rep data structure is proposed which would allow tracking of both a given face’s geometric type and primitive generating object during the solid modeling process. A technique termed primitive object tracking is presented which would allow object decomposition (feature extraction) based on this additional data. Existing feature extraction techniques are augmented by the application of the object decomposition technique for the recognition and extraction of various feature types; internal voids, single and multi-surfaced holes, and boundary perturbations. Lastly, a brief discussion is presented of required modification and their implications to B-Rep solid modeling to implement and use primitive object tacking techniques.
CATI: A Computer Aided Tolerancing Interface
Authors: Söderberg Rikard 
Published: March 2021

Abstract
This work presents an interface for tolerance analysis in a CAD system. A method for picking up necessary information from a 2D drawing is developed and implemented as an interface in a commercial CAD system. The interface communicates with an external calculation program which determines unknown tolerance limits using the normal distribution model. Results from the calculation program is in the end used by the interface to present measures with tolerances on the drawing.
The advantage of using CATI in preliminary design is discussed, and a strategy for treating interrelated tolerance chains is presented.
Geometrical and Topological Issues in NMT-Based Modeling
Authors: Saxena Mukul , Srivatsan Rajan , Davis Jonathan E. 
Published: March 2021

Abstract
The Non-Manifold Topology (NMT) Radial Edge data structure, along with the supporting set of Euler operators, provides a versatile environment for modeling non-manifold domains. The operators provide the basic tools to construct and manipulate model topology. However, an implementation of the base functionality in a geometric modeling environment raises some geometry-related issues that need to be addressed to ensure the topological validity of the underlying model. This paper focuses on those issues and emphasizes the use of geometry in the implementation of topological operators. Enhancements to the topology manipulation operations are also discussed. Specifically, this paper describes (i) a geometry-based algorithm for face insertion within the Radial Edge data structure, (ii) a manifestation of the face-insertion algorithm to resolve topological ambiguities that arise in the design of topological glue operators, and (iii) enhancements to the topology deletion operators to meet application-specific requirements.
Object Extent Determination for Algebraic Solid Models
Authors: Ganter M. A. , Storti D. W. 
Published: March 2021

Abstract
This paper presents methods for determination of spatial extent of algebraic solid models. Algebraic solid models (ASM) are a variation of implicit solid models defined by implicit polynomial functions with rational coefficients. Spatial extent information, which can be used to enhance the performance of visualization and property evaluation, includes silhouettes, outlines and profiles. Silhouettes are curves on the surface of the solid which separate portions of the surface which face towards or away from a given viewpoint. The projection of the silhouette onto the viewing plane gives the outline of the solid, and the bivariate implicit function which defines the area enclosed by the outline is called the profile. A method for outline determination is demonstrated using concepts from algebraic geometry including polar surfaces and variable elimination via the Gröbner basis method and/or resultants. Examples of outline generation are presented and a sample profile function is constructed.
Generic Features of the Inverse Kinematics for Control of One Class of Seven-Jointed Robotic Workcells
Authors: Ashton N. S. , Charif M. M. , Davidson J. K. 
Published: March 2021

Abstract
The controllably dexterous capability of a class of seven-jointed serially connected robots is quantitatively confirmed, and the generic features of the inverse kinematics for their control are developed. The generic features are the specific motions of the outermost two joints of the wrist and the aggregates of the motions of the remaining rotary joints in each direction. Of the two global functions among the actuator-coordinates, one is operationally equivalent to a six-jointed substitute-manipulator and the other is a seventh-order polynomial that relates the motion at the last joint of the wrist to the task-motion. The robots in the class can provide a full rotation at constant speed to the end-effector about every task-axis (for a resolution of one degree of angle between adjacent task-axes) through each controllably dexterous fixture-point without encountering the mechanical effects of axis-dependence. For those robots with three P-joints in the arm, this dexterity of motion is accomplished with all joints operating at speeds within 2.0 times the speed of the task rotation. In this paper, the quantitative evaluation is restricted to manipulators with 3R spherical wrists having successively orthogonal axes, the first of which is mounted at right-angles to the adjacent joint-axis in the arm. The CPU-time for executing each computational step is short enough to be useful for on-line operations.
A Novel Theory on Grasping Force Control in a Multifingered Robotic Hand
Authors: Gao Xiaochun , Song Shin-Min 
Published: March 2021

Abstract
Based on inspiration of human grasping activities, a new idea is developed in this paper that grasping forces in a multifingered robotic hand can be regulated and controlled through its compliance by actively coordinating small joint motions in its fingers. According to this idea, a grasping force control model is formulated by means of a compliance model developed by the authors before, and a novel theory is then developed for grasping force control in a multifingered robot hand. The developed theory is expected to lead to a new force control method which could serve as a promising alternative for the active stiffness method. As an application of the developed theory, a two-fingered planar robotic hand is also analyzed, and the simulation results verify the developed theory.
Closed-Form Forward Displacement Analyses of the 4-5 In-Parallel Platforms
Authors: Lin W. , Crane Carl D. , Duffy J. 
Published: March 2021

Abstract
In this paper, we study a class of in-parallel platforms whose six legs are connected either singly or in a pair-wise fashion at the vertices of a quadrilateral top platform and a pentagonal base. A forward displacement analysis in closed-form is performed for each distinct case and polynomials ranging from 16th degree to 32nd degree are derived and verified numerically.
Simplified Mechanism Design
Authors: Jensen Preben W. 
Published: March 2021

Abstract
Mechanisms with one or more degrees of freedom can be developed from kinematic chains and must include open kinematic chains. Open kinematic chains can give greatly simplified solutions to complex problems. One example is described. Kinematic synthesis is another subject, where easy solutions can be obtained using degenerate cases of the Burmester curves. Making the right design assumptions is a third area, where simplifications can be made.