bluuebunny/crossref_metadata_2025_split huggingface dataset:
Combustion Flowfield Prediction for CVD Diamond Synthesis
Authors: Dong Mingchun , Lilley David G. 
Published: March 2021

Abstract
A computer code has been developed to simulate the combustion flowfield of an axisymmetric jet flame impinging normally on to a flat plate. Premixed oxygen and acetylene emerges from the jet nozzle, and complexities include turbulence and high temperature chemical kinetics. In CVD diamond synthesis, parameters of interest include the fuel-oxygen ratio and the distance from the heat nozzle to the surface. Combustion flow field predictions are given for acetylene and oxygen flames (all fuel rich), axisymmetric-vertical impingement on an adiabatic surface to show the effects of varying the nozzle-substrate separation distance, nozzle size, overall equivalence ratio and flow rate on the flowfield and substrate temperature. These have been shown to have dramatic effects on the rate of diamond growth on the surface.
An Analytical Interpretation of High Strain Rate Material Behavior During Early Time Plastic Deformation in the Taylor Impact Test
Authors: Jones S. E. , Maudlin Paul J. , Gillis Peter P. , Foster Joseph C. 
Published: March 2021

Abstract
Using information from experiments and continuum mechanics code calculations, an analytical stress/strain-rate relation is developed. This relation is valid during the early time plastic deformation phase of the Taylor impact test. The results show good correlation between experiment and the continuum code predictions.
Constitutive Modeling of Composite Laminates With Progressive Ply Cracking
Authors: Hahn H. T. , Kiusalaas J. , Burns B. P. , Bogetti T. A. 
Published: March 2021

Abstract
A computational procedure is proposed to determine effective constitutive relations for composite laminates with progressive cracking. The procedure is based on the assumption that the effective stiffness of a cracked ply in a laminate can be determined by analyzing the cracked ply by itself independent of the rest of the laminate. A polynomial failure criterion is used to predict ply cracking using effective ply stresses. The procedure provides a full set of effective laminate stiffnesses as well as crack densities in constituent plies.
Stability Considerations of Primary Loadings of a Stepladder
Authors: Collins David , Kaplan Mitchell P. , Czerwinski James 
Published: March 2021

Abstract
The effects of certain loadings on a stepladder are investigated using finite element analysis. The ladder considered is a light-duty six-foot aluminum stepladder with the user standing on the fourth step. The loading results from the user’s weight and from his exerting a horizontal force against a fixed object to his right. The analyses show that as long as all four feet of the ladder are constrained not to move on the floor, structural deflections and stresses are acceptable. However, if the right two feet are allowed to move, a moderate push can result in sudden collapse of the ladder.
Further analyses demonstrate that torsional compliances within the structure, which also allow tolerance for an irregular floor, are the major structural participants in this instability, and that the rigidity and strength of the entire structure can be substantially increased by the stiffening of certain substructural components.
Integrating Concurrent Engineering and FEA Into Engineering Technology Programs
Authors: Kitto Kathleen L. 
Published: March 2021

Abstract
Strategies involved in concurrent engineering are being integrated into the engineering technology programs at Western Washington University Because finite element analysis (FEA) is an integral part of concurrent engineering, it too has been added to the curriculum Students explore such topics as design for manufacturability, lifetime ownership factors, world class manufacturing, building in quality and time-to-market, even in their first engineering technology course. Students are first introduced to FEA in basic mechanics courses. Then they take a more complete FEA project course in the senior year In that course, students use FEA to model components, and verify their models in the laboratory.
This paper describes the concurrent engineering integration efforts at Western Washington University and includes course outlines and laboratory examples Examples from student projects are given. The paper also addresses the issues complicating the integration of analysis and simultaneous engineering into engineering technology programs.
Global Local Finite Element Method (GLFEM) in Gear Tooth Stress Analysis
Authors: Moriwaki I. , Fukuda T. , Watabe Y. , Saito K. 
Published: March 2021

Abstract
The present study is concerned with an application of the Global Local Finite Element Method (GLFEM) to a gear tooth stress analysis. The GLFEM is a numerical analysis technique which combines finite element solutions and classical analytical ones on the basis of the energy principle. In this method, the classical analytical solutions give an almost exact stress field to the elements in which the stress varies very rapidly and/or the stress concentration is found. A fine subdivision, therefore, is not required.
In the application of the conventional finite element method to the gear tooth stress analysis, the fine subdivision is required especially at the positions near tooth bottom and the load applied point. Hence, only two dimensional analysis is available for common use. Furthermore, in order to determine an exact location of a critical section on which a fillet stress is maximum, we must use complicated procedures, e.g. an iteration of subdivision for searching the maximum nodal stress.
In the present paper, the GLFEM is applied to the gear tooth stress analysis to show that even the rough subdivision enables us to make the precise three dimensional analysis. It also guarantees an easy determination of the critical section. Thus, we show the effective future of the GLFEM to the gear tooth stress analysis.
Computer Simulation of Torsional Waves in a Single Gear Transmission
Authors: Mioduchowski A. , Nadolski W. 
Published: March 2021

Abstract
The theory of one dimensional torsional elastic waves is used for the dynamical analysis of a discrete-continuous model of a single gear transmission. The method allows for the calculation of results either as functions of time or as functions of location. These results can be put together into a 3D time-space display offering an interesting tool in simulation of torsional waves in a single gear transmission.
The Influence of Flank Deviations on the Vibration of a Helical Gear Pair Transmitting Light Load
Authors: Umezawa Kiyohiko , Houjoh Haruo , Matsumura Shigeki 
Published: March 2021

Abstract
This paper introduces a simulator which can depict the rotational vibration of a helical pair having any kind of deviations transmitting light load. Under light load condition the contact pattern does not extend to full length of ideal contact tooth surface. Under this condition, the determination of the contact pattern sometimes become very sensitive to the numerical calculation error. In the worst cases, calculation leap into endless loop. The developed simulator was improved robuster.
This paper firstly derives how we can obtain the relationship between the deflection and the load distribution of single pair of mating teeth. Secondary, the determination method of multi tooth pair load sharing is introduced. Afterwards, the simulation is experimentally verified with various kinds of tooth flank deviations.
Through this study, an easy design method to realize a low vibration helical gear is suggested.
Tooth Surface Fatigue of AISI9310 Steel Spur Gears
Authors: Kotorii H. 
Published: March 2021

Abstract
With a JIS 0 class Spur Gears of AISI9310 steel, module 4, presure angle 25 degree tooth profile, the numbers of pinion teeth 21 / gear teeth 29 carburized and tooth surface hardness HRc 59, the relationships of the load and the service life (S-N) diagram were investigated by running test on the power-circulated type gear tester.
MIL-L-23699 equivalent synthetic oil at 50° C were fed at a ratio of 0.8 l/min and circumferential velocity of 8.8 m/sec.
Also the running performance of the gears, variation of tooth profile errors, affairs of damage, etc. were examined.
Types of tooth surface fatigue mere scoring, spalling, or micropitting.
A durability limit of Hertz-stress was assumed to be around 2GPa at the load cycle of 108.
A General Method for Computing the Distance Between Two Moving Objects Using Optimization Techniques
Authors: Ma Ou , Nahon Meyer 
Published: March 2021

Abstract
Presented in this paper is a general method used to find the distance between two moving objects. This distance is defined as the length of the shortest path from one object to the other. The objects are assumed to be composed of arbitrary quadratic surface segments. The distance problem is formulated as a quadratic programming problem with linear and/or quadratic constraints, which is solved by efficient and robust quadratic programming techniques. Attention is focused on implementation in order to achieve computational efficiency for real-time applications. Computing tests show that the computational speed of this method is of linear order in terms of the total number of bounding surfaces of the two objects. It is also shown that, with a minor modification, this method can be used to calculate the interference between objects. A corresponding general software code has been implemented, and will be used for kinematics and dynamics modelling and simulation of space manipulators including situations with transient topologies, contact of environment, and capture/release of payloads.
Design of Machine Tool Spindle for Minimum Workpiece Cylindricity Error
Authors: Li John , Musukula Vijayachander , Trabia Mohamed B. 
Published: March 2021

Abstract
The design of machine tool spindle for minimum cylindricity error is presented. The shape of the spindle portion between the bearings, usually cylindrical, is reconfigured to increase the spindle rigidity. Two methods of reconfiguration are presented. In the first method, the spindle is reshaped as a smooth body of revolution. In the second method, the spindle is reshaped as a stepped shaft. Effects of bearings rigidity and fatigue stresses are also considered.
Design of an Aircraft Tire: A Study in Modeling Uncertainty
Authors: Vadde S. , Swadi S. , Bhattacharya N. , Mistree F. , Allen J. K. 
Published: March 2021

Abstract
During the early stages of project initiation, the information available to a designer may be uncertain (imprecise or stochastic). In response to this need, two extensions of the crisp compromise Decision Support Problem using fuzzy set theory and Bayesian statistics are developed to model uncertainty in design problems. The fuzzy compromise DSP is used to model imprecise information and the Bayesian compromise DSP is used to model stochastic information. The design of an aircraft tire is used as an illustrative example.
Modeling and Dynamic Analysis of the Suspension System of a Front Loaded Washing Machine
Authors: Türkay O. S. , Sümer I. T. , Tuğcu A. K. 
Published: March 2021

Abstract
A non-linear time invariant dynamic model of the suspension system of a front-loaded washing machine has been formulated, programmed for simulation, and assessed experimentally A drum mounted in a tub which is hung to the cabinet by three linear helical springs and supported by two dry-friction dampers rotates together with an eccentric laundry mass. The displacement responses due to centrifugal excitation have been obtained for the spin-dry cycle ranging from 0rpm to 650rpm until steady-state has been reached The comparison of simulation and experimental results has demonstrated the validity of the model by predicting the steady-state and transient peak-to-peak vertical and horizontal amplitudes within 5% and 11% errors, respectively The mechanical performance and the “striking” and “stepping” phenomena can be assessed for prototype design purpose by undertaking a parametric investigation to the end of optimizing the design.
Direct Position Analysis of the 4-6 Stewart Platforms
Authors: Chen Ning-Xin , Song Shin-Min 
Published: March 2021

Abstract
Although Stewart platforms have been applied in the designs of aricraft and vehicle simulators and parallel robots in many years, their closed-form solution of direct (forward) position analysis has not been completely solved. Up to the present time, only the relatively simple Stewart platforms have been analyzed. Examples are the octahedral Stewart and the 4-4 Stewart platforms, in which two pairs of both upper and lower joint centers are coincident. The former results in in an eighth degree polynomial and the latter results in an eighth and a twelfth degree polynomials for different cases. The single unknown variable is in the form of square of a tan-half-angle. This paper further extends the direct position analysis to a more genearl case of the Stewart platform, the 4-6 Stewart platforms, in which two pairs of upper joint centers of adjacent limbs are coincident. The result is a sixteenth degree polynomial in the square of a tan-half-angle, which indicates that a maximum of 32 configurations may be obtained. It is also shown that the previously derived solutions of 4-4 and and 3-6 Stewart platforms can be easily deduced from the sixteenth degree polynomial by setting some geometric parameters be equal to 1 or 0.
A Finite Element Formulation for the Dynamic Analysis of Machine Components Fabricated From Composite Materials
Authors: Semos A. , Chassapis C. 
Published: March 2021

Abstract
In this paper finite element procedures are presented for analyzing the elastic-dynamic behavior of mechanical components fabricated from fiber-reinforced composite materials. An arbitrarily laminated composite plate element is created which allows the analysis of components that are moving in three dimensional space. The five D.O.F. per node static model of S. C. Panda and R. Natarajan is used as a basis for the derivation of the dynamic model. The elemental equations of motion are derived from Hamilton’s Principle. The formulation considers the total kinetic and strain energies of the moving element, together with the work due to bending, caused by the transversely acting external forces, as well as that due to the foreshortening of the element, caused by axially applied loads.
Instability and Chaos in Quadruped Gallop
Authors: Nanua Prabjot , Waldron Kenneth J. 
Published: March 2021

Abstract
A dynamic model for the two dimensional quadruped has been developed. The main body is modelled as a rigid bar and each leg consists of a constant stiffness spring, a viscous damper and a force actuator. Based on symmetry principles, a controller has been devised that will enable the quadruped to gallop at constant speed. The controller consists of two parts: an energy controller which will apply the required amount of force through the legs, and the speed controller that will control the forward speed by appropriately placing the legs. It will be shown that the body pitch need not be explicitly controlled. The stability of this controller will be examined using Poincare maps. Stable systems show either periodic or quasi-periodic response. This system also exhibits chaotic behavior and chaotic response leads to instability. The stability of the system with changes in the initial conditions, as well as variations in the system parameters, will also be examined. It will be shown that the system is stable for a range of leg stiffnesses. Outside this range, the system shows chaotic behavior.
Transmission Error Analysis of a Parallel Symmetric Geared Linkage Mechanism
Authors: Yang Ji-Hou 
Published: March 2021

Abstract
Many machine systms consist of parallel symmetric mechanisms, but-the unsymmetric force transmission between two sides may often happen, due to the dimentional errors of mechanism and the clearences in the kinematic pairs. This makes a machine of low efficiency and bad power transmission capacity.
In this work, as a model of a punch press, a parallel symmetric geared crank and slider mechanism is analyzed about the unsymmetric input torque and the reactions in the kinematic pairs between two sides due to the errors of input angle and radius of crank. The behavior of journal clearences during the force transmitting process are also considered.
The analyzed results are well suit to the experimental results and hence have actual use to the design and manufacturing of machine.
Evaluation Criteria for Conceptual Designs of Deployable-Foldable Truss Structures
Authors: Warnaar Dirk B. 
Published: March 2021

Abstract
Techniques for the creative design of deployable-foldable truss structures have recently been developed to result in the generation of all possible designs for some given general characteristics of the structure [1–4]. This article discusses the development of evaluation criteria for these designs, so that the process of selection and enumeration of desirable candidates can be facilitated. To accommodate the evaluation of large numbers of conceptual designs, special attention is given to the development of criteria that are suitable for implementation in automated procedures for the design selection. Examples are provided that demonstrate the use of these criteria in a design selection process.
Automated Cam-Mechanism Synthesis and Analysis
Authors: Eventoff Arnold T. 
Published: March 2021

Abstract
An automated computer-based method for deriving the shape of machine elements such as cams is described for complex mechanisms. Traditional cam synthesis concentrates on follower motion; the method described here enables complete control of the required output motion. Output motion is defined for any constant or variable camshaft velocity. The process is not limited by the degrees of freedom, follower shape, follower suspension, or complexity of the mechanism linking followers to output points.
The method includes a velocity analysis to predict cam shape, pressure angle, and relative velocity of the follower with respect to the cam. This analysis allows immediate visual inspection and further dynamic and wear analyses. Cam-follower contact stress is readily calculated for an entire cycle of motion during the synthesis process.
An example consisting of a five-bar linkage displaced by three cams is synthesized using the methodology. The general method described facilitates development of mechanisms previously not feasible using conventional methods. Servomotor command displacement profiles required for complex systems can also be derived using this method.
Circuit Rectification for Four Precision Position Synthesis of Four-Bar and Watt Six-Bar Linkages
Authors: Mirth John A. , Chase Thomas R. 
Published: March 2021

Abstract
The circuit defect arises when a linkage can not be moved between all precision positions without disassembly. The synthesis of linkages by precision position methods is simplified by reducing the design space to include only those linkages that are free of the circuit defect. Solutions for four-bar and Watt six-bar mechanisms are developed here.
Multiple circuits in the Watt six-bar chain arise from circuits within a four-bar chain of the linkage or from the limits of motion that are imposed on the entire linkage by the two four-bar subchains. The circuit defects that are introduced by these conditions are eliminated through the sequential analysis of the Burmester curves for four-position synthesis. The points on the Burmester curves where the circuit attributes change are found. The curve segments yielding mechanisms that exhibit the circuit defect are then eliminated from consideration. The process is numerical and based on the complex number formulation of Burmester theory.
Kinematic Analysis of the Generalized Tracta Coupling and its Variant Mechanisms
Authors: Fenton R. G. , Buchal R. O. , Zhou Y. B. 
Published: March 2021

Abstract
The generalized tracta coupling R0-RERR and its variant mechanisms R0-ERRR, R0-RRER and R0-RRRE are all kinematically analyzed by a new Vector Algebraic Method. The input-output displacement equations of these mechanisms are derived as fourth order polynomials. Compared to existing methods, the new approach presented in this paper has standardized analysis steps and compact algebraic expressions. For each of the different variant mechanisms the analysis procedure is the same.
Static Analysis of Spherical nR Kinematic Chains With Joint Friction
Authors: Larochelle Pierre , McCarthy J. M. 
Published: March 2021

Abstract
This paper presents the static analysis of general spherical nR simple open or closed kinematic chains with joint friction. The internal loading on each link is found to consist of a bending moment and a torsional moment. The goal of this analysis is to determine these moments which are then used in designing the link.
The moment and force balance equations for each link yields a linear system of equations which define the internal moments of the mechanism and the output torque on the driven crank for a given input torque. A Coulomb model of joint friction is used to determine the friction torque along the axis of a joint. The joint friction model requires an iterative solution.
The purpose of this algorithm is to provide a means of computing the complete internal and external loading on the members of spherical chains while including frictional effects in order to facilitate the design of a functional spherical mechanisms.
Dynamics of a Cross-Slider Mechanism As Used in an Internal Combustion Engine
Authors: Nesbit Steven M. 
Published: March 2021

Abstract
A four cylinder internal combustion engine was developed which utilizes a cross-slider as its internal mechanism. The mechanism consists of two perpendicular sliders, each connected at midpoint to a floating gear which mates to two grounded gears pinned off center. A complete kinematic and dynamic analysis was performed to study mechanism behavior in an engine application. As a result of the analysis, the kinematics and dynamics of the mechanism were defined, the engine performance was simulated, the components of the engine were properly sized, and a total force and torque balance was achieved. This article will present the development of the kinematic and dynamic expressions that describe the cross-slider mechanism as used in an internal combustion engine.
Identification of Isomorphism of Kinematic Chains Through Link’s Adjacent-Chain Table
Authors: Chu Jin-Kui , Cao Wei-qing 
Published: March 2021

Abstract
A completely new concept about the kinematic chain, called the link’s adjacent-chain table (shortened as ACT), is originated in this paper. It is an invariant which can be used to describe the topological relationships between links in the kinematic chain (shortened as KC). In comparison with the traditional representation of the KC, i.e. with the adjacent matrix, link’s ACT is much more audio-visual and simpler. Using the link’s ACT, the isomorphism of the KC can be easily determined. Among the existing methods for the identification of the isomorphic graphs, link’s ACT takes the least time in calculation. So it’s introduction of the link’s ACT leads to a effectual solution to identify the isomorphism of the KC.