bluuebunny/crossref_metadata_2025_split huggingface dataset:
p-Version Axisymmetric Shell Element for Geometrically Nonlinear Analysis
Authors: Liu Joseph H. , Surana Karan S. 
Published: March 2021

Abstract
This paper presents a p-version geometrically nonlinear (GNL) formulation based on total Lagrangian approach for a three node curved axisymmetric shell element. The approximation functions and the nodal variables for the element are derived directly from the Lagrange family of interpolation functions of order pξ and pη. This is accomplished by first establishing one dimensional hierarchical approximation functions and the corresponding nodal variable operators in the ξ and η directions for the three and one node equivalent configurations that correspond to pξ + 1 and pη + 1 equally spaced nodes in the ξ and η directions and then taking their products. The resulting element approximation functions and the nodal variables are hierarchical and the element approximation ensures C0 continuity. The element geometry is described by the coordinates of the nodes located on the middle surface of the element and the nodal vectors describing top and bottom surfaces of the element.
The element properties are established using the principle of virtual work and the hierarchical element approximation. In formulating the properties of the element complete axisymmetric state of stresses and strains are considered hence the element is equally effective for very thin as well as extremely thick shells. The formulation presented here removes virtually all of the drawbacks present in the existing GNL axisymmetric shell finite element formulations and has many additional benefits. First, the currently available GNL axisymmetric shell finite element formulations are based on fixed interpolation order and thus are not hierarchical and have no mechanism for p-level change. Secondly, the element displacement approximations in the existing formulations are either based on linearized (with respect to nodal rotation) displacement field in which case a true Lagrangian formulation is not possible and the load step size is severely limited or are based on nonlinear nodal rotation functions approach in which case though the kinematics of deformation is exact but additional complications arise due to the noncummutative nature of nonlinear nodal rotation functions. Such limitations and difficulties do not exist in the present formulation. The hierarchical displacement approximation used here does not involve traditional nodal rotations that have been used in the existing shell element formulations, thus the difficulties associated with their use are not present in this formulation.
Incremental equations of equilibrium are derived and solved using the standard Newton-Raphson method. The total load is divided into increments, and for each increment of load, equilibrium iterations are performed until each component of the residuals is within a present tolerance. Numerical examples are presented to show the accuracy, efficiency and advantages of the present formulation. The results obtained from the present formulation are compared with those available in the literature.
p-Version Two Dimensional Beam Element for Geometrically Nonlinear Analysis
Authors: Orth Fabian J. , Surana Karan S. 
Published: March 2021

Abstract
This paper presents a p-version geometrically nonlinear formulation (GNL) based on total Lagrangian approach for a three node two dimensional curved beam element. The hierarchical element approximation functions and the corresponding nodal variables are derived directly from the Lagrange family of interpolation functions. The resulting element displacement approximation is hierarchical and can be of arbitrary and different polynomial orders in the longitudinal and the transverse directions of the beam element and ensures C0 continuity. The element geometry is described by the coordinates of the nodes located on the axis of the beam (middle surface) and the nodal vectors describing the top and bottom surfaces of the element.
The element properties are established using the principle of virtual work and the hierarchical element displacement approximation. In formulating the properties of the element complete two dimensional stresses and strains are considered hence the element is equally effective for very slender as well as extremely deep beams. Incremental equations of equilibrium are derived and solved using the standard Newton-Raphson method. The total load is divided into increments, and for each increment of load, equilibrium iterations are performed until each component of the residuals is within a preset tolerance. Numerical examples are presented to show the accuracy, efficiency and advantages of the present formulation. The results obtained from the present formulation are compared with those reported in the literature.
The formulation presented here removes virtually all of the drawbacks present in the existing GNL beam finite element formulations and has many additional benefits. First, the currently available GNL beam formulations are based on fixed order of approximation for the displacements and thus are not hierarchical and have no provision for changing the order of approximation for the displacements u and v. Secondly, the element displacement approximations in the existing formulations are either based on linearized displacement field for which a true Lagrangian formulation is not possible and the incremental load step size is severely limited or are based on nonlinear nodal rotation function approach in which case even though the description of displacement for the element is exact but additional complications arise due to the noncummutative nature of nonlinear nodal rotation functions. The p-version displacement approximation used here does not involve traditional nodal rotations that have been used in the existing beam formulations, thus the difficulties associated with their use are not present in this formulation.
Simplified Thermal Analysis for Embedded Piping
Authors: Joodi Pirooz M. H. 
Published: March 2021

Abstract
The growing use of tubular structures in nuclear reactor facilities such as pipes, conduits and ducts that are buried underground, requires more detailed stress analysis to demonstrate structural integrity as required by Section III of the Boiler Pressure Vessel Code and other applicable industry codes.
Thermal behavior of the pipe and soil interference can be conservatively evaluated by implementing the thermal characteristics and properties of the pipe into the expressions, as deduced by previous studies, which are made for the seismic analysis of buried piping. This paper presents procedures to evaluate the different pipe/soil parameters to be applied in those expressions, and explains these equations from designers perspectives and, finally, suggests an approach to combine various pipe stresses to check against ASME Boiler and Pressure Vessel Code Section III. The analysis assumes that the soil is linearly elastic and homogenous and the structure is a straight slender solid or hollow beam with a uniform, symmetrical cross section that satisfies the conditions of the elementary theory of beams on elastic foundations.
On the Flow Start-Up in Convergent-Divergent Nozzles
Authors: Opalka Klaus-Otto 
Published: March 2021

Abstract
Shock lube tests were carried out to investigate the influence of the divergent half angle of four planar convergent-divergent nozzles on the incident-shock formation, and on the pressure signature downstream from the nozzle. A diaphragm was mounted in the throat of these nozzles and located at the upstream edge of the test section window of high-quality optical glass through which shadowgraphs and schlieren pictures could be taken. The objectives of this investigation were to obtain optical records of the flow start-up processes in these divergent nozzles immediately after rupturing the diaphragm, and to facilitate comparisons with hydrocode computations. The optical measurements were complemented by measurements of the static pressure at three locations downstream from the nozzles. The test set-up and the results of these experiments are presented and compared with the results of one dimensional hydrocode computations.
Teaching the Concept of Total Design
Authors: Echempati Raghu 
Published: March 2021

Abstract
When the engineering students graduate and are about to enter the “real world of engineering” — be it an engineering industry (as a coop or as an engineer), or return to an educational institution for further studies, they must appreciate and possibly be already familiar with the concept of “Total Design of the Mechanical System”. This means that the students be given excellent training before they graduate, to fulfil the current and the future needs of an industry.
This paper presents the methodology adopted by the author based on his own experience as a consultant to an industry, in teaching 2 different design courses at the Michigan Technological University. The feedback obtained (from time to time) from the student alumni has been a totally rewarding experience.
Enhancing Product Development Teaching With a Computer-Aided Product Development Guide
Authors: Wilson Clement C. , Kennedy Michael E. 
Published: March 2021

Abstract
By many measures, U.S. industry is no longer the leader in developing world class products. U.S. product development and manufacturing systems need substantial improvement to assure a successful future. The Superior Engineering Design Program (SEDP) was created within the University of Tennessee’s College of Engineering in 1987, with a mission to improve the teaching and practice of product development. Within this program, the authors have developed a computer-based learning tool, the “SEDP Product Development Guide” (“the Guide”), to help senior and graduate engineering design students learn “superior” product development processes.
The Guide incorporates the latest product development strategies and techniques, as practiced by some of industry’s most competitive product development teams. The software is an assistant, but is specifically not an “artificial intelligence” system that purports to make decisions for the user. Rather, the guide provides structure and asks “critical” questions at appropriate times during the product development process. While design tools are available for assistance, the student engineer is always responsible for answering the “critical questions” satisfactorily to assure that the designed product meets customer requirements.
A prototype SEDP Product Development Guide has been installed for evaluation in the SEDP’s Engineering Design Center, located in the University’s Mechanical and Aerospace Engineering Department.
Energy Optimal Control Algorithm Based on Central Difference Approximation of Equation of Motion With Application to Robot Control
Authors: Nakhaie-Jazar Gholamreza , Naghshineh-Poor A. H. , Ravanbakhsh K. 
Published: March 2021

Abstract
Optimal control of robotic manipulator has a complex nature. Many different control and optimal control algorithms have been developed. However, these algorithms are either based on simplified equation of motion or are tedious to implement to set up.
In this work the equations of motion are approximated by central difference technic and Taylor series expansion, while path of motion is divided in finite segments. The motion is assumed to have zero velocity at beginning and at the end of the motion, without loss of generality. The whole time and path of motion is arbitrary, but fixed, after the option. The problem of energy optimal control is reduced to minimizing a scalar function of many but finite variables with equality and inequality constraints. By applying modified Hooke and Jeeves method, actuator torques at any time are calculated.
The preparation time for problem set up and execution time are small, and programming efforts are reasonably low.
The algorithm is implemented for a 2R and 3R robotic manipulator, and results are presented.
Computer Control of Turning Center and Industrial Robot
Authors: Hua Xun 
Published: March 2021

Abstract
This presents a computer control system for a turning center workstation in Computer-integrated Manufacturing Systems (CIMS) environment. The system structure is first introduced. Then, an information exchange between different devices inside the workstation is studied. These devices are made by different manufacturers so that the communication between them becomes a problem. The principle of developing a software to implement the communications is presented, which includes the use of a software platform, the development of data acquisition system (DAS) for robots, and the writing of an information request. Finally, the operations of the system is presented.
A Study on a High-Speed NC Gear Grinding Machine Using Screw-Shaped CBN Wheel
Authors: Emura T. , Wang L. , Arakawa A. 
Published: March 2021

Abstract
This paper describes a basic study for the development of a high-speed NC gear grinding machine using screw-shaped CBN wheel.
Gear grinding machines using screw-shaped grinding wheel have already developed by Reishauer and others. However, their productivity is not high, because they use one thread type grinding wheel and the rotary speed of the workspindle is very low.
The maximum rotary speed of the grinding spindle developed by the authors is 12,000 rpm and that of workspindle is 3,000 rpm. They are enough speed for gear grinding. The desired accuracy for an angle sensor of grinding spindle is more than 20 ″pp in the case of the multithread type grinding wheel. The ordinary shaft encoder cannot respond at such a high-speed. Therefore the authors used a magnetic scale of high-accuracy and an induction type magnetic head. After experiments, it became clear that two-phase type PLL proposed by T. Emura is useful for detecting low level signals obtained from the magnetic head.
Since the maximum rotary speed of the workspindle is raised to 3,000 rpm, we cannot use any reduction gear. Thus a direct-drive method with an inertial damper was used. The workspindle is controlled by using the two-phase type PLL.
When we grind gears, the initial setting between rotary angles of grinding wheel and work is required. The authors tried to automatically set the initial rotary angles by using a CCD camera and a microcomputer.
Dynamic Analysis of a Planetary Gear System
Authors: Donley Mark G. , Steyer Glen C. 
Published: March 2021

Abstract
Noise reduction in geared systems is usually achieved by minimizing transmission error or by changing the gear train’s dynamic response. While considerable research has been directed in the past to understanding and controlling the transmission error, the same can not be said of the system dynamic response. Recent efforts at modifying the dynamic response to reduce the sensitivity to transmission error have proven to be very rewarding for parallel shaft gearing applications.
In this paper, these efforts are extended to planetary gear set applications. A major difference between planetary gear sets and parallel shaft gears is that in planetary gear sets many gear meshes carry load instead of just one. This feature poses a modeling problem as to how to combine responses due to transmission errors at each loaded mesh to determine the total response. A method is proposed in this paper in which transmission errors at different gear meshes are combined into net vertical, net lateral and net tangential transmission errors. A methodology for computing dynamic mesh force response due to these net transmission errors and for identifying critical components that control the gear train system dynamics is presented. These techniques are useful in understanding the effects of system dynamics on gear noise and in developing quiet gear design. To demonstrate the salient features of the proposed method, an example analysis of a transmission with a planetary gear set is presented.
A Comparative Study of Selected Gear Mesh Interface Dynamic Models
Authors: Blankenship G. Wesley , Singh Rajendra 
Published: March 2021

Abstract
There is a consensus among modern gear researchers that variation in gear mesh stiffness and transmission error are the primary sources of vibratory excitation in most moderately to heavily loaded gear drives. However, several schools of thought exist in the literature on how to incorporate these mesh stiffness and transmission error concepts into a dynamic model. In this paper, a formal expression for an elastic gear mesh force vector is developed and selected gear mesh interface models, which exemplify most of the common modeling approaches in use today, are compared on a common mathematical basis. The various modeling strategies, their inherent philosophies and assumptions are made clear. All of the models examined employ a common spatial domain analysis methodology which pervades the field of modem gear dynamics. The focus of this study is limited to the quasi-steady state, non-resonant dynamic analysis of a single involute gear pair operating below critical shaft speeds such that shaft whirling and gyroscopic effects are negligible, and under loading conditions sufficiently high to prevent loss of tooth contact due to gear backlash phenomenon. The need for extended analytical models, which consider multi-dimensional excitation and better describe force transmissibility via the gear mesh interface, is identified. This forms the basis of an on-going comprehensive investigation which expects to clarify several unresolved issues in gear dynamic modeling; future publications will report such studies.
The Generating Space for Parabolic Motion Error Spiral Bevel Gears Cut by the Gleason Method
Authors: Gosselin Claude , Cloutier Louis 
Published: March 2021

Abstract
Because of their inherent pseudo-conjugate natures, spiral bevel gears cut by the Gleason method basically transmit motion in a non uniform manner. This motion non uniformity, or motion error, repeated at each tooth engagement and at high speeds and loads, can cause vibrations in transmissions and contact-entry impact loads on gear teeth which affect the life of a gearset. It is customary to make small changes to machine settings in order to produce gear pairs with vastly improved kinematics. Therefore, machine setting changes must be carefully chosen such as to produce appropriate unloaded kinematical motion error that will cancel tooth bending deflection and contact deformation at a given load, and thus reduce noise and vibrations due to motion non-uniformity.
This paper presents a study on the effects of machine settings, such as cutter tilt, machine center to back and offset, on the unloaded kinematical motion error. Applying CAD Boolean operations on the results, it is found that, for a given speed ratio, an infinite number of cutter tilt, work offset and machine center to back combinations will produce gear sets with convex parabolic motion error curve of any desired amplitude. Moreover, the amplitude of motion error curves can be linked directly to contact bias on the tooth flank. Thus, gear sets with any parabolic motion error in the unloaded state can be produced, such as to cancel tooth bending deflection and contact deformation in the loaded state.
Effect of Lubricant Jet Location on Spiral Bevel Gear Operating Temperatures
Authors: Handschuh Robert F. 
Published: March 2021

Abstract
An experimental study was conducted to determine the effect of lubricant jet location on spiral bevel gear bulk temperatures. Transient surface temperatures were also measured. Tests were conducted on aircraft quality spiral bevel gears in a closed-loop test facility. Thermocoupled pinions and an infrared microscope were used to collect the pertinent data. A single fan jet lubricated the test gears. Lubricant flow rate (lubricant jet pressure) and applied torque were also varied. The results of this study showed that jet placement had a significant effect on the gear bulk temperatures.
Load Distribution Analysis of Journal Bearings Operating Under Mixed Lubrication Conditions
Authors: Ramamohana Rao A. , Mohanram P. V. 
Published: March 2021

Abstract
When the lubricant film that separates two loaded members becomes thin enough, the asperities on the surfaces begin to interfere. Hydrodynamic journal bearings invariably experience this phenomenon during starting and stopping which is called mixed lubrication. In this case, a part of the applied load is carried by the hydrodynamic action of the fluid film and the remainder through asperity contacts. The part of the load supported by the asperities is significant in that it determines the wear life of the bearing to a large extent. In this work, analytical procedures for the determination of these two components of load based on statistical nature of surface topography have been developed. An algorithm for the estimation of limiting load from wear consideration has been presented. The effect of variation of typical surface topography parameters which undergo change during wear process viz. standard deviation of profile sum, combined radius of curvature of asperities, on hydro-dynamic and asperity load supporting capabilities and true area of contact has been discussed. The computations have been illustrated with experimental data.
Belt Slip: A Unified Approach
Authors: Gerbert Göran 
Published: March 2021

Abstract
Slip measurements on thick flat belts, V-belts and V-ribbed belts running on small pulleys reveal that the slip is much higher than can be predicted with classical creep theory. Shear creep plays an important role and special care must be taken when analysing the shear deflection of the V-belt and the ribs of the V-ribbed belt. Other mechanisms are present as well. The behaviour in the seating and unseating regions changes the direction of the frictional forces in these regions on the driver pulley.
A unified slip theory is presented for flat belts, V-belts and V-ribbed belts considering creep, shear, seating/ unseating and compliance. Measurements and theory fit very well for practical tension levels. At low tension the measured slip is higher than the predicted one for V-belts and V-ribbed belts, which probably depends on the poor fit between the belt and the grooved pulley.
A Closeness Degree Method for Multi-Objective Optimization of Belt Transmission
Authors: Qun Lin , Meijuan Wu 
Published: March 2021

Abstract
A mathematical model for multi objective optimization design of belt transmission is proposed in this paper. The normal fuzzy distribution is used to convert the ideal and non-inferior solutions into fuzzy subsets over the space of objective function values. The optimal solution which is closest to the ideal one could then be found on the basis of closeness degree method.
Limiting Conditions in Gear Shaping With Allowance for Trimming
Authors: Sankaranarayanasamy K. , Shunmugam M. S. 
Published: March 2021

Abstract
Gear shaping process is a generation process by which precision gears can be produced. In some cases, because of the generation motions, interference conditions exist in the process. These interferences may introduce preferable conditions on the gears produced, in a few cases. Such limiting conditions are presented here, after allowing for the trimming of the profile due to these interferences.
Eigensolutions of Damped Torsional Systems
Authors: Huang Yuan Mao , Kon L. G. 
Published: March 2021

Abstract
This study eliminates the conventional assumptions that the disks are rigid with infinite stiffnesses and shafts are very slim with negligible stiffnesses for the equivalent mass-elastic system. Both ends of the damped system can be free or fixed.
The extended transfer matrix method is used with Newton. Raphson technique. A mathematical model is derived and a computer code is generated to determine the eigensolutions of the system. The calculated results are compared and show good agreement with the available data. Therefore, the tool can be used to predict the performance and to design power trains.