bluuebunny/crossref_metadata_2025 huggingface dataset:
Optimal Design of a Regenerative Clutch-Brake
Authors: Geis D. G. , Uzgiris S. C.
Published: November 2010

Simplified analytical techniques are developed for the optimal design of a regenerative clutch-brake. The analysis yields parametric equations for the clutch-brake geometry such that wear and friction sensitivity are optimized. Test results indicate satisfactory correlation with the analytically predicted performance.
Flow Behavior of Hematite Slurries
Authors: Jennings Harley Y.
Published: November 2010

This paper describes our laboratory study of the flow behavior of aqueous hemalite slurries. Viscosity and flow data are given for slurries of up to 40 percent hematite by volume (76 percent by weight). These results show that solids concentration and particle size distribution have much more effect on flow than does temperature. These and supporting laboratory data are discussed in terms of practical problems in pipelining slurries.
A Geometric Study of In-Bin Blending
Authors: Bagster D. F.
Published: November 2010

A segregated flow model, taking account of residence-time distributions, has been developed to describe the process of blending material by recirculation. Variables having an effect on mixing have been investigated and the model was tested by comparison with the results from a laboratory hopper recirculation experiment. Suggestions are made for increasing the rapidity of mixing and for carrying out blending tests on the full scale. The effect of particle segregation was also examined.
On A Class of Cam-Type Angular-Motion Compensators
Authors: Buchsbaum F. , Freudenstein F.
Published: November 2010

The kinematic analysis and static force analysis is described for a class of angular-motion compensators, in which the phase angle between two concentric shafts is controlled by a fixed cam in the form of an eccentric, and a roller follower bearing against two spring-loaded rollers mounted on the shafts.
A Proposed Prosthesis for the Lumbar Spine
Authors: Baumgarten J. R.
Published: November 2010

This paper chronicles a kinematic study of the lower spine. The synthesis of a four-bar mechanism to serve as an implanted appliance is shown. The device and the radio-logical technique for determining relative motion of vertebrae have not been clinically tested. This work was initiated to aid in diagnosis of ruptured disks and is offered as an alternative to fusion of vertebrae. It is recorded here for possible use by other investigators.
Some Advantages of Product Criteria in Component Optimization
Authors: Brown Max L.
Published: November 2010

In optimum design the optimizing criterion is a mathematical compromise among performance, cost, life, and conformity to constraints. This paper makes use of the fact that for every linear sum criterion there exists an equivalent product criterion which yields the same solution (extremum function). A method to obtain the proper form of this criterion is presented along with several distinct advantages of using it, including: (1) elimination of the variable “constant” which changes whenever a constraint changes (such as Lagrange multipliers); (2) separation of independent solutions (such as material and shape); (3) great reductions in the work required to obtain a solution when the mathematical models take the form of products. These advantages are demonstrated in three example problems utilizing a novel approach to finding the functions which render products of definite integrals extremum.
The Effect of Abrasion Resistance and Thermal Properties of the Cemented Carbide Cutting Tool Grade on the Flank Wear Characteristics
Authors: Ber A.
Published: November 2010

Correlation of the wear characteristics with abrasion resistance factor—1/(vol. loss) in a standard test—has been established in a low speed range where the temperatures involved in the cutting action are relatively low. It was found that a lower abrasion resistance factor produced, (in specified time and cutting conditions except speed, which was a variable), higher flank wear at a range of low speeds—20 to 100 SFPM or 6 to 55 per min—but, when speed is increased, other properties than abrasion resistance are involved, i.e., hot hardness characteristics and thermal conductivity coefficient are able to withstand higher velocities. Speed versus thermal conductivity coefficient curve was established where the cutting time and flank wear levels were constant. Feed and depth of cut were also constants. The investigation demonstrated that thermal conductivity coefficient of the cutting grade material is very significant and plays a major role in its ability to resist transfer of heat from the cutting zone to the flank of the tool, and thus no reduction of hardness due to temperature. This phenomenon results in the ability of the tool to perform in high speed range.
Improved Maintenance of Machinery Through “Baseline” Vibration Measurements
Authors: Catlin J. B.
Published: November 2010

The purpose of this paper is to present a method for increasing the value of vibration analysis as a tool in the maintenance of machinery. The method, termed “baseline” method, is described and the use of various types of vibration measuring instruments and data recording explained. Seven steps involved in setting up a baseline program are discussed with information provided as to specific measurement and analysis technique. Various applications of the method, designed to expand the usefuless of vibration analysis, are also outlined.
Statistical Analysis, Estimation, and Optimization of Surface Finish in the Grinding Process
Authors: Zohdi M. E.
Published: November 2010

A method of identifying the individual as well as the combined effects of the different independent factors on the surface finish in the grinding process is presented. Physical experimentation coupled with subsequent statistical analysis, the factorial experimentation technique, were applied to further the understanding of this process. Mathematical models were developed to estimate the quality of the dependent factor, the surface finish. Optimum conditions that result in the best surface finish with the maximum rate of metal removed are evaluated and discussed.
The Minimum Weight One-Dimensional Straight Cooling Fin
Authors: Maday C. J.
Published: November 2010

The Minimum Principle is used to obtain the minimum weight one-dimensional cooling fin without the length-of-arc assumption. This approach enlarges the class of optimum fin designs available for consideration. The heat-transfer coefficient and the, thermal conductivity can be temperature dependent. It is shown that the tip dimension vanishes for typical profiles. The results are specialized to make a comparison with results obtained with the length-of-arc assumption. With initial conditions obtained from the approximate method for kθ0/q0 = 10, the fin is 15 percent shorter than the classical parabolic profile and contains about 1.6 percent less material. The shorter fin length in this example and the flexibility in specifying the heat flux per unit fin base area for any fin are practical design considerations. The optimum fin is described by a nonlinear two-point boundary-value problem whose solution is obtained numerically. Computational guides are provided.
Use of Shock Compared With Harmonic Excitation in Machine Tool Structure Analysis
Authors: Tlusty J. , Lau K. C. , Parthiban K.
Published: November 2010

The paper recapitulates the method of analyzing stability against chatter of machine tools as it has been practised by one of the authors for many years. Several new features of the method are presented and, mainly, comments are given on the use of shock excitation for determining both the receptances of the structure and its mode shapes. The method itself consists of comparing results of cutting tests and of excitation tests for various directional orientations of the cut in the structure and of identifying the contribution of the individual modes to the resulting degree of stability.
Active Machine Tool Controller Requirements for Noise Attenuation
Authors: Mitchell E. E. , Harrison E.
Published: November 2010

The use of feedback control to regulate the position of the cutting tool relative to the workpiece on a machine tool such as a lathe is examined with respect to the reduction of vibratory noise effects on workpiece surface finish. Both control mode and controller characteristics are examined relative to noise effect attenuation. An examination of system stability (the chatter tendency) is also included as a necessary part of the evaluation of each type of controller that is considered.
A Displacement Analysis of Spatial Six-Link 4R-P-C Mechanisms—Part 3: Derivation of Input-Output Displacement Equation for RRRPCR Mechanism
Authors: Duffy J. , Rooney J.
Published: November 2010

The input-output displacement equation is expressed as a degree eight polynomial in the half-tangent of the output angular displacement. The equation can be used to generate the input-output function for the spatial five-link RRCCR mechanism. The results are illustrated by numerical examples.
Environmental/Power System Considerations—Thyristor Crane Drives
Authors: Campbell J. D.
Published: November 2010

There is an accelerating trend toward application of modern static control and drive technology to cranes and heavy material handling systems, and the backbone of these systems are the thrysitor and the static regulator with its many printed circuit cards and small electronic components. This article reviews these elements with respect to performance while subjected to typical crane operating conditions, including shock, vibration, dirt, low line voltage, etc. Design features and special packaging considerations for crane installations are discussed, as well as alternate design approaches.
Analysis and Design of Thin Struts With Large Elastic Displacements: Part 2—Design Tables, Curves, and Procedures
Authors: Kurajian G. M. , Na T. Y. , Holbert D. L.
Published: November 2010

Employing the method developed in Part 1, the practical engineering design aspects are treated for the selected problem of an eccentrically loaded thin strut. The strut is made to experience large elastic deflections, and the end supports are simultaneously pinned and restrained by torsion bar springs. Realistic values, ranges, and combinations of physical parameters are assigned and design curves, data, and tables are presented. The paper is so written that the engineer may use Part 2 independent of study of Part 1 if he so desires to bypass the mathematical and property study of the solution of the defining equations.
Influence of Hydrostatic Pressure on Void Formation at Hard Particles
Authors: Austen A. R. , Avitzur B.
Published: November 2010

An experimental technique for drawing and fluid extrusion of artificial composites is described. This method is utilized in a quantitative study of suppression of void formation and growth in materials through the application of hydrostatic pressure during deformation. Critical pressures, which are the minimum hydrostatic pressures required to suppress void initiation, are investigated. The experimental critical pressure data are compared with similar analytical data derived from a related upper bound equation.
Plane Strain Forging—A Lower Upper Bound Approach
Authors: Nagpal V. , Clough W. R.
Published: November 2010

A general kinematically admissible velocity field applicable to forging of a rectangular strip of a incompressible material is presented. Generalized shape of any dead zone, if assumed, can be obtained in terms of process parameters from this velocity field. Two different upper bound solutions for average forging pressure are obtained from simple velocity fields which are special cases of proposed general velocity field. Numerical results of the solutions show improvement over previous upper bound solutions published in literature over a certain range of process parameters.
Influence of Transverse Anisotropy on the Plastic Collapse of Plates and Shells
Authors: Chakrabarty J.
Published: November 2010

A modification of Tresca’s yield criterion is discussed for plane stress in anisotropic materials, when the yield stress in the thickness direction is higher than in any direction perpendicular to it. Special consideration is given to the determination of collapse loads for symmetrically loaded plates and shells having this kind of anisotropy. It is found that the carrying capacity significantly increases with the degree of transverse anisotropy represented by a single parameter μ.
Necessary Conditions for Homogeneous Plastic Deformation of Composite Materials in Uniaxial Tension
Authors: Iscovici S. , Avitzur B.
Published: November 2010

With a basis of previously developed upper bound analysis, the conditions required for homogeneous deformation in a composite material tensile specimen are determined. As in the earlier work, relative strength of reinforcing particles, particle-matrix bonding, geometry variations, environmental pressure, and the possibility of void formation are all included in the analysis. The necessary conditions for homogeneous deformation are provided as explicit expressions for allowable ranges of relative particle strength and relative environmental pressure. A detailed procedure for graphical presentation is provided and examples are used to demonstrate the application and typical results.
Modeling Machine Tool Chatter by Time Series
Authors: Pandit S. M. , Subramanian T. L. , Wu S. M.
Published: November 2010

Machine tool chatter is formulated as self-excited random vibration with white noise forcing function. The formulation takes into account the unknown factors and random disturbances present in the cutting process when chatter occurs. Based on this formulation, a procedure for modeling chatter using the time series of sampled observations on vibration signals is developed. Feasibility of this procedure is established by modeling data obtained from a turning operation under conditions of severe chatter.
Speedy Design of Helical Compression Springs by Nomography Method
Authors: Tsai T. K.
Published: November 2010

This paper introduces a few new equations and a performance nomogram for the design of helical compression springs. The procedures for calculation are simple, speedy, and accurate.
Casing Design in Directionally Drilled Wells
Authors: Woodlan Bruce , Powell G. E.
Published: November 2010

Design of casing strings for directionally drilled wells requires that consideration for bending load be included with calculations concerning tension, collapse, and burst. The nature of the bending load calculation is such that it cannot be incorporated into a nomograph but, instead, must be calculated by trial and error. THUMS Beach Company uses a combination of graphs and calculating procedures to facilitate designing casing in highly deviated holes.
Effects of Coupled Extensional-Torsional Oscillations in Wire Rope During Ocean Salvage and Construction Operations
Authors: Skop R. A. , Samras R. K.
Published: November 2010

It is well established, and intuitively clear from the geometry of a wire rope, that a tensile load produces not only an extension but also a rotation of the rope (or a torque if both ends of the rope are prevented from rotating). This property of a wire rope leads, in a dynamic situation, to coupling of the extensional and rotational waves propagating through the rope. Classically, this coupling has been neglected, and only extensional waves treated, when analyzing the dynamic behavior of wire ropes used as lifting lines. Here, the effects of including the coupled oscillations in the dynamic analysis of lifting lines are considered, and the results are compared to those generated by the classical technique. Significant differences in the predicted dynamic response of the lifting line are found. A comparison of the predictions with experimental data also shows the importance of considering coupled extensional-torsional oscillations for obtaining an accurate description of lifting line dynamics.
The Anchor-Last Deployment Problem for Inextensible Mooring Lines
Authors: Rupe Robert C. , Thresher Robert W.
Published: November 2010

A lumped mass numerical model was developed which predicts the dynamic response of an inextensible mooring line during anchor-last deployment. The mooring line was modeled as a series of concentrated masses connected by massless inextensible links. A set of angles was used for displacement coordinates, and Lagrange’s Method was used to derive the equations of motion. The resulting formulation exhibited inertia coupling, which, for the predictor-corrector integration scheme used, required the solution of a set of linear simultaneous equations to determine the acceleration of each lumped mass. For the selected cases studied the results show that the maximum tension in the cable during deployment will not exceed twice the weight of the cable and anchor in water.
The Quadratic Curve and the Trajectory in the Shear Zone in Metal Cutting
Authors: The J. H. L.
Published: November 2010

The quadratic curve was investigated as an approximation of the streamline in the steady-state shear zone during metal cutting. Experimentally, a very fine grid of parallel lines (spacing 25 μ, depth 6 μ) was inscribed on the work face through a simple method which eliminates the problems associated with the photographic and etching techniques. Quick stops were taken using an explosive device for cutting speeds of 50, 150, and 250 m/min. Next, several quadratic curves were fitted to the experimental streamline, which was measured at six points along its path. The two tangents at the start and end of the shear zone were also measured. Of the three types (ellipse, hyperbola, and parabola) studied, the hyperbola and, specifically, the rectangular hyperbola (x2 − y2 = c2) gave the best fit with experiment. Trajectory deviation in these cases is <1 percent and the strain-rate deviation is <6 percent. These are in the order of magnitude of the experimental errors.
Characterization of Carbide Tool Wear and the Influence of Titanium Carbide Coatings
Authors: Payne D. A. , Bind J.-M. , Ham I. , Biggers J. V.
Published: November 2010

Typical data are presented for the chemical and physical characterization of commercial carbide cutting tools before and after machining tests on heat treated alloy steel AISI-4340. Particular attention is paid to the morphology of crater wear relating chemical constitution and carbide microstructure to tool/workpiece interactions. Direct observation of chemical impurity transfer is reported and a mechanism proposed for the deleterious liquid phase attack of intergranular cobalt. The influence of TiC coatings on improved cutting performance is discussed; and the characteristics of several different coatings correlated with varied machining results. Characterization techniques employed include optical and scanning electron microscopy, electron microprobe analysis and x-ray emission identification.
Exhaust Emissions of Selected Railroad Diesel Locomotives
Authors: Bryant A. H. , Tennyson T. A.
Published: November 2010

Measurements were taken of the composition of exhaust gases from railroad diesel locomotives operating in normal service at various stages of their respective maintenance cycles. A major objective was to determine how the exhaust quality of these engines related to emission standards for heavy-duty diesel powered highway vehicles. Results varied from unit to unit, but generally indicated that improvements would be necessary if such regulations were applied to railroad diesels. Another primary objective was to develop basic information on concentrations of important exhaust constituents and to determine whether existing analytical techniques and instrumentation were sufficiently developed to provide reliable and reproducible data on the composition of diesel engine exhaust and the quality of visible emissions. Results indicate that specific concentration of exhaust constituents are a function of engine design and the physical condition of the engine. Furthermore, currently available analytical equipment can be used with confidence for measuring carbon monoxide, oxides of nitrogen, and unburned hydrocarbons in samples taken from the exhaust of diesel locomotives. Techniques and methodology were tested to the extent that reproducible results were obtained for the preceding constituents.
Kempe’s Linkages and Their Derivations
Authors: Dijksman E. A.
Published: November 2010

In the paper, three cells are considered, namely, Peaucellier’s cell, Kempe’s cell and a new one which is derived from Kempe’s cell. Each of them gives rise to straight-line mechanisms of the first and the second kind containing eight bars. Further, some of them are combined using reflection principles and the principle of cognation. This may lead to lifting devices producing rectilinear motions of a link that is contained in the mechanism. In the paper, ideas have been brought forward allowing the designer to assemble new linkages which are cognated to the older, historical ones, such as the ones devised by Kempe.
A Method of Controlling the Shaft Misalignment in a Gear Testing Machine by “Prestressed” Externally Pressurized Journal Bearings
Authors: Cusano C. , Mirarefi A. , Radzimovsky E.
Published: November 2010

“Prestressed” externally pressurized journal bearings employing capillary restrictors as compensating elements are installed on a four-square gear testing machine for the purpose of investigating the frictional phenomena in gearing. The bearings are designed so that the position of the shafts can be aligned with the geometric axes of the bearings by operating the bearing system at zero, positive, or negative eccentricities. These operating conditions are made possible by employing capillary restrictors whose conductance is larger on the loaded side of the bearings than on the unloaded side. Analytical data are presented which give the load capacity, lubricant flow rate requirements, and stiffness of the bearing for given geometry of the bearing and capillary restrictors and for a given eccentricity ratio. In addition, analytical and experimental data are presented from which, for a given load, the required supply pressure can be selected so that the bearing system, on the gear testing machine, operates at zero eccentricity.
The Ocean as a Renewable Source of Energy
Authors: Griffin O. M.
Published: November 2010

The oceans and their environment have long been envisioned as renewable sources of energy. It is the purpose of this paper to assess the feasibility of drawing on the sea for power and to determine the extent to which the oceans are likely to serve future energy needs. A review is made of recent U. S. funding levels for the research and development of renewable energy sources during the fiscal years 1971–1975, and a study is made of the technical and environmertal acceptability status of tidal, wind, and sea thermal power generation systems. The estimated costs of these environmental power sources are compared with the prevailing power costs for nuclear and coal plants. On the basis of these comparisons, recommendations are made for a program of research and development culminating in the construction of prototype plants for wind and sea thermal power plants. Tidal power generation is found to be technically feasible but economically uninviting at present.
An Operational 40 kG Superconducting Beam Transport Magnet and its Cryogenic System
Authors: Allinger J. , Bamberger J. , Danby G. , DeVito B. , DiLullo C. , Foelsche H. , Gibbs R. , Hsieh S. , Jackson J. , Prodell A.
Published: November 2010

A superconducting 40 kG magnet system 4 meters long is now operating which bends the 30 billion electron volt primary proton beam produced by the Brookhaven Alternating Gradient Synchrotron. The magnet design is unique in that commercially available niobium titanium composite superconductor and relatively high purity aluminum are used in combination with low carbon steel magnet cores to provide excellent magnetic and thermal stabilization. This magnet system is operating on line in a closed loop, zero loss helium refrigeration system. Details of the magnet structure, dewars, and cryogenic system will be discussed.
A General Method for the Fatigue-Resistant Design of Mechanical Components—Part 1: Graphical
Authors: Mitchell L. D. , Vaughan D. T.
Published: November 2010

This paper presents a graphical method for the direct solution of fatigue design problems where the mode of overloading is to be taken into account. The material fatigue failure diagram is modified to give a new failure diagram called the safety diagram. The infinity of possible component designs is described by a line called the locus of design points. The intersection of the locus of design points with the safety failure diagram yields a direct design solution. Because of graphical difficulties, the method is limited to those cases where the locus of design points and the load lines are straight lines.
Optimal Design of a Reflected-Core Nuclear Reactor
Authors: Lam F. Y. , Townsend M. A.
Published: November 2010

Optimal results are presented for the design of a reflected-core spherical reactor. Complete model development is given. The result is a highly nonlinear system with 2 equality and 13 inequality constraints. Substantial savings in core and reflector materials are indicated; from this, investigation for similar savings in more complex models of present-day reactors (cylindrical core, multigroup theory) is suggested. Because of the model complexity and nonlinearity, a special direct-search algorithm based on the Flexible Tolerance Search was developed, reference [1].
Large Displacement Matrix Analysis of Elastic/Viscoplastic, Plane Frame Structures
Authors: Shieh Rong Chung
Published: November 2010

Within the framework of lumped mass/elementary beam theory, a large displacement matrix analysis of elastic/perfectly viscoplastic plane frame structures undergoing primarily flexural deformations and following a constitutive power law is first formulated. A general purpose computer program based on the step-by-step computational procedure in conjunction with the fourth order Runge-Kutta integration technique is then developed. The computerized study is then used in an analytical/experimental correlation study of the dynamic response of a laboratory impact test problem of a mild steel plane frame dropped into a narrow rigid pole obstacle at 20 mph (32.2 km/hr); good analytical and experimental correlation results are obtained up to 2 percent of strain. An example problem of inelastic response of an automobile bumper (beam) subjected to impact loading is also given. Discussion of the results with regard to strain rate sensitivity effects on dynamic plastic behavior and comparison of the “exact” solution with those obtained under certain simplified approximations are made.
Calculation of Acoustical Resonances in Irregular Cavities With Application to Noise-Induced Stress in Expansion Joints
Authors: Baylac G. , Planchard J. , Gregoire J. P. , Pailly C.
Published: November 2010

An analytical and experimental study of the acoustic behavior of seven and nine corrugation expansion joints (bellows) used in a nuclear reactor is presented. Resonant frequencies obtained from a computer program using a matrix method are given. Experimental test results on seven corrugation expansion joints are in good agreement with the computations. It is concluded that the calculation of acoustic frequencies of expansion joints with internal sleeves can be utilized to avoid the coincidence of these frequencies with those of a mechanical or flow-induced noise nature and thus reduce the loads on expansion joint corrugations.
Stress Relaxation in Press-Fitted Joints
Authors: Goel R. P.
Published: November 2010

When contact pins, wire wrap posts, etc., are press fitted into printed circuit boards, the contact force at the interface of a post and plate relaxes with time. Much of the relaxation of the contact force occurs immediately after the connection has been made. Theoretical estimates on the reduction in contact force until a steady state (a steady state is assumed to be reached when the stress rates become 1 percent of their initial values) is reached are presented. Since most of the relaxation of the radial stress component occurs in the vicinity of the hole, the effect of adjacent joints on the relaxation characteristics of a joint are neglected. And, therefore, only an idealized geometry of a thin circular plate with a single press-fitted hole is considered.
Bending and Vibration of Plates of Variable Thickness
Authors: Chen S. S. H.
Published: November 2010

The problem of bending and vibration of plates of variable thickness and arbitrary shapes and with mixed boundary conditions was solved by a modified energy method of the Rayleigh-Ritz type. General trial functions of deflection were obtained, one in Cartesian coordinates for rectangular plates and the other in polar coordinates for other shapes. The forced boundary conditions were satisfied approximately by introducing fixity factors which depended upon the prescribed conditions. Central deflections for circular plates subjected to static bending were within 0.2 percent of published results while they were within 1 percent for rectangular plates. The differences of natural frequencies of various rectangular plates were from 0.05 percent for simple, 2.9 percent for clamp, and up to 4.3 percent for free-free plates based on the published values.
V-Belt Life Prediction and Power Rating
Authors: Oliver L. R. , Johnson C. O. , Breig W. F.
Published: November 2010

A new service-life prediction and rating formula is presented for use in designing V-belt transmission drives. Capability of current V-belt fatigue formulas is extended to account for effect of cord stress range. The formula is derived from (a) statistically designed and analyzed life tests, (b) cord bending stress measurements, and (c) Fourier series and finite element solutions for cord stress distribution.
Effect of Damping on the Lateral Critical Speeds of Rotor-Bearing Systems
Authors: De Choudhury Pranabesh , Zsolcsak Stephen J. , Barth Eugene W.
Published: November 2010

Rigid support lateral critical speeds along with undamped system critical speeds and mode shapes are presented for typical rotor-bearing systems. The steady-state unbalance response analysis presented shows the effect of fluid-film bearing damping on the rotor response. Experimental results show reasonably good correlation with analytical results. The investigation shows that a rational rotor-bearing system design approach can be made for high-speed rotating machinery using the analytical tools.
On the Design of Mooring Lines for Deep Water Applications
Authors: Niedzwecki J. M. , Casarella M. J.
Published: November 2010

As ocean engineers begin to extend their analytical and design capabilities from the shallow regions of the oceans to the deep regions it becomes necessary to examine the established computational algorithms and determine to what extent they can be applied to problems of current interest. In this spirit, this paper generalized the catenary equations for inextensible mooring lines, by examining them in a dimensionless form, which allows the generation of certain design curves applicable to a broad class of naval off-shore operations. As an example, candidate mooring lines for an offshore platform are considered in water depths ranging from 1000 to 4000 ft with the maximum tension prescribed at 5 percent excursion from station. The candidate mooring lines consist of single component (all wire rope, all chain) as well as multiple component (wire rope/chain) combinations. For this example it was observed that for wire rope/chain mooring lines a large restoring force could be obtained and that the magnitude of the restoring force was dependent upon the depth of water and the amount of wire rope outboard of the offshore platform. Further it was observed that certain wire rope/chain combinations offer some desirable characteristics as the water depth increases.
Identification of a Work Restricted Forging Process for Optimization by Adaptive Control
Authors: Kwiatkowski A. W. , Biswas S. K.
Published: November 2010

The role of process identification in optimization of manufacturing systems is discussed in general terms. Optimization of a work-restricted forging process is considered in detail and it is shown that its identification consists of estimating the parameters of a normal regression model. Since forging parameters are variable, routine updating of identification estimates is required. The response of the sequence of updated estimates obtained after a process change has occurred is of importance to the effectiveness of optimization. The problem is examined by applying two methods of updating to data which stimulate the occurrence of a change in the parameters of the forging model. The first is valid for stationary processes only and yields long sequences of inaccurate estimates after a process discontinuity. The second method recovers the accuracy in fewer updating steps but does this at the expense of a greater sampling variability of the estimates when the process is steady. A test for process homogeneity is employed to decide at every stage of updating whether the sequence should be continued or a new one started from fresh.
Multiple Internal Resonance in a Structure-Liquid System
Authors: Ibrahim R. A.
Published: November 2010

The autoparametric coupling of a vibrating structure with liquid sloshing modes is demonstrated by means of a system consisting of a two degree of freedom structure carrying a rigid container partially filled with liquid. When the system is subjected to vertical excitation the liquid container oscillates up and down and, under certain internal resonance condition, it moves laterally as well. Energy is then exchanged between the structure vibration modes and the liquid sloshing modes. Nonlinear inertia terms in the equations of motion predominate in the behavior of the system undergoing autoparametric resonance. For two simultaneous internal resonance relations and external resonance near one of the frequencies involved in the internal resonance relations, the system performance is investigated theoretically and experimentally. The system shows unsteadiness and instability for most of the conditions considered, and these unstable motions are demonstrated in the experimental investigation. The effects described must be regarded as possible sources of structural failure in practical engineering systems.
Regenerative Drive for Subway Trains—Part 1: Mechanical Accumulator Design
Authors: Flanagan R. C. , Suokas L. A.
Published: November 2010

A regenerative drive system for subway trains is mathematically modeled and numerically evaluated for the Toronto Bloor-Danforth Subway Line. The scope of the study dictates a multipaper presentation of system and component modeling. This first paper designs and optimizes the mechanical accumulator subsystem (bearings, seals, losses) of the vehicle propulsion package. Preliminary design criteria (stress-energy relationships) predict the required performance capability of the one and two accumulator per vehicle systems; the need for high energy densities is of secondary importance compared to the required power density for vehicle operation. Accumulator performance tests suggest ease of integration with the current drive system. Subsequent papers model the external and internal drive systems, and numerically optimize the flywheel control concept and accumulator size; day savings, on a round-trip basis, are predicted in the order of 26 percent.
Regenerative Drive for Subway Trains—Part 4: Overall System Performance
Authors: Suokas L. A. , Flanagan R. C.
Published: November 2010

Vehicle energy consumption and savings for the Toronto Bloor-Danforth Subway Line are evaluated. Two vehicle loads are chosen (for this evaluation) indicative of rush-hour and nonrush-hour operation. A comparison test run shows the numerical simulation to be within a few percent of actual measured data. Evaluation of round trip results indicate energy savings as high as 33 percent for a large vehicle weight, but based on daily operation, savings are more realistically 26 percent. The effect of long coasts (5 percent) on actual station runs is again shown to be detrimental to the energy savings for the regenerative system.
Spinning Frame Noise Sources
Authors: Stewart N. D. , Emerson P. D. , Bailey J. R.
Published: November 2010

As part of a Coordinated Textile Industry Noise Reduction Program, a study of the sources of spinning frame noise has been conducted. Techniques of source modification and narrow-band frequency analysis were used. Several machines were studied. Major noise sources were found to be the ring-traveler and spindle-bobbin systems. Other sources identified were the drive cylinder, drive tapes, idler pulleys, vacuum system, and gears. Relative importance of the sources and differences among machines is discussed. Suggestions are offered for ways to reduce noise from some of the sources. Work is continuing to evaluate and develop the most feasible methods of spinning frame noise reduction.
Application of MOIRE Technique to the Determination of Stresses on the Rake Surface of Single Point Cutting Tool Models
Authors: Murty R. L. , Qayyum M. A.
Published: November 2010

The stresses developed on the rake face of single point tool models under the action of a static force by applying MOIRE technique have been investigated. Three tool models with varying rake angles (+30, 0, and −30 deg) are studied and the stresses developed on the rake face are compared.
A Simplified Technique for Prediction of Collapse Modes in Crash-Impacted Structural Systems
Authors: Saczalski K. J. , Park K. C.
Published: November 2010

A pseudostatistical technique utilizing linear system parameters for the determination of strain energy concentration patterns within shock-impacted structural systems forms the basis for identifying the most probable regions and modes of collapse. The technique provides a simplified design-oriented tool for determining the energy management capabilities and crashworthiness of a given structure without the necessity of numerous, costly, destructive tests. Examples of the technique, as applied to a dynamically loaded beam-column and spatial frame, are given and compared qualitatively with experimental results.
Approximate Straight-Line Motion From Simple Spatial Mechanisms
Authors: Reid M. W. , Hunt K. H. , Nolle H.
Published: November 2010

A simple form of spin-surface is investigated and it is shown how, via this surface, spatial mechanisms may readily be synthesized to give twelve-point straight line motion or twelve-point circular motion. The spatial mechanisms are obtained by adding links to plane four-bar linkages.
Momentum Balancing of Four-Bar Linkages
Authors: Wiederrich J. L. , Roth B.
Published: November 2010

The primary objective in this work is the determination of conditions for reducing the angular momentum fluctuations (i.e., vibration) transmitted to the frame of a completely force balanced four-bar linkage. This approach leads to relatively simple design equations for determining the inertial properties of the links for good momentum balancing. The essence of this procedure is that it yields analytical results as opposed to the computer-based search techniques required by most previously published methods, which are based on reducing the shaking forces and moments rather than the momentum fluctuations. Furthermore, this method allows for off-line mass distributions (i.e., the center of mass of the link is not on the line of pivots) and, as we show in the paper, this can result in better momentum balancing than the in-line case to which most previous works have been restricted. Some numerical examples are given and the results are compared to similar results obtained by minimizing the RMS shaking moment.
Prediction of Cylinder Flow Pressures in Mass-Flow Bins Using Minimum Strain Energy
Authors: McLean A. G. , Arnold P. C.
Published: November 2010

Jenike, et al. [1] have presented a minimum strain energy theory to predict cylinder flow pressures in mass-flow bins. The complete variation of strain energy pressures is depicted by bounds requiring considerable numerical effort to develop for a specific cylinder geometry. Design charts are presented, but these are available for only two circular cylinder geometries. This paper summarizes and clarifies the minimum strain energy theory for predicting cylinder flow pressures. A single bound approximation which allows the magnitude of the peak flow pressure to be determined for both axisymmetric and plane flow cylinders is presented. This peak pressure may also be estimated by a single calculation of strain energy pressure. The usefulness and accuracy of these procedures are illustrated by reworking the example presented by Jenike, et al. [1].
Cable Kinking Analysis and Prevention
Authors: Ross A. L.
Published: November 2010

Kinking of electromechanical cables in underwater applications is a continuing design problem. One mechanism for this is the formation of a loop due to the combined action of torsion and tensile loads which then tightens and forms a kink upon subsequent increase of tensile load. This mechanism is analyzed to determine the critical combinations of tension, torsion, mechanical properties, and cable slack required for kinking and to provide rules for the prevention of kinking. Other kinking mechanisms are also dicussed. The analyses are shown to compare well with published experimental data.
Analysis of Feeding and Orienting Systems for Automatic Assembly—Part 2: Vibratory-Bowl Feeding Systems
Authors: Murch L. E. , Poli C.
Published: November 2010

The procedure used to obtain the general design data of various orienting devices for vibratory-bowl feeders and the general performance characteristics for vibratory-bowl feeding systems are described for the case of an edge-riser orienting device and a feeding system used for feeding and orienting rectangular prisms. The results of the testing and analysis are summarized on data sheets similar to those contained in a handbook of feeding and orienting techniques for small parts currently being assembled at the University of Massachusetts.
A New Constant Velocity Coupling
Authors: Milenkovic V.
Published: November 2010

A constant velocity coupling has been developed that does not resemble any coupling built before. It was intended for a specialized application, with specifications that are outside the range of any existing designs. A kinematic model as well as a subscale prototype have been constructed, and the latter was successfully tested. The principles of the coupling are discussed in some detail, with emphasis on their kinematic aspects. The formal proof for the constancy of the velocity ratio of this coupling is presented.
A Dynamic Simulation of the Impact of Regional Air Pollution
Authors: Enscore E. E.
Published: November 2010

The problem of predicting cost associated with the environment around us is complex. In this paper a Regional Economic Leontief Input-Output is calculated as a function of an air pollutant, sulfur dioxide. The model presented is a multi-stage optimization model which uses linear programming. The model uses an objective function to be optimized subject to the flow of the Leontief Input-Output model and environmental level constraints. The model is dynamic in a Markovian sense in that each stage is dependent only on the previous stage. This dependency arises from the way the environmental variable and excess demand are handled. The environmental variable level for stage n + 1 is determined in stage n and the excess demand from stage n is carried over to stage n + 1. An example is used to demonstrate the use of the model.
Submarine Pipeline Analysis With an Elastic Foundation by the Finite Element Method
Authors: Schmidt W. F.
Published: November 2010

This paper presents a procedure for solving the nonlinear differential equations of bending for pipelines suspended between a lay barge and the ocean floor using the finite-element method. In order to eliminate the usual difficulty of determining the suspended length, a discontinuous foundation modulus is introduced into the formulation to account for the interface condition where the pipe lifts off the ocean floor. Examples are presented to illustrate the effectiveness, efficiency, and flexibility of the procedure, and it is concluded that the procedure should provide a useful tool enabling easy analysis of various schemes for pipelaying.
Dynamic Simulation of Freight Car and Lading During Impact
Authors: Kasbekar P. V. , Garg V. K. , Martin G. C.
Published: November 2010

A dynamic analysis is presented to explain damage to railroad cars and ladings resulting from impacts. In the analysis, a mathematical model consisting of the car body and freight in the car is presented. Each freight element assumes three degrees of freedom for the computer simulation. A parametric study is made to establish sensitivity of car parameters and impact conditions. The study should be useful to aid in finding means for controlling impact damage and in designing packaging materials.
A Systematic Approach to the Adaptive Control of the Electro-Discharge Machining Process
Authors: Tseng M. M.
Published: November 2010

Electro-discharge machining removes metal with very short lived electric pulses between electrode and workpiece which are immersed in dielectric liquid. With limited feedback available to the operator, the process is very difficult to approach and maintain efficient machining performance. A systematic approach is taken here by applying incomplete process information for off-line process planning and by minicomputer technology for on line adaptive control. Off-line process planning determines the optimal current level and pulse duration for the roughing and finishing. By sensing down feed and pulse efficiency, on line adaptive control adjusts servo voltage and off time. Experimental investigations with two repetitions show that the system can complete the job with a shorter machining time by detecting and responding more efficiently to disturbances in the process than manual control.
Some Aspects of Flat Surface Grinding with Intermittent Cross-Feed
Authors: Banerjee J. K.
Published: November 2010

Part I: A Wheel Wear Mechanism. Using a constant maximum grit-force hypothesis for a fixed wheel-work combination, a stable and progressive wear-land model is developed as a function of the machine settings and its mechanical and thermal limitations are discussed. Experiments conducted with several wheel-work materials, both during dry and wet grinding justify the proposed wear mechanism and its limitations with respect to the machine settings. Part II: The Force Equilibrium. Under a stable wear mechanism as proposed in Part I, the grinding force is shown to be a simple linear function of a combined machine settings’ parameter; the slope of the line gives, in the range of the machine settings used, a constant specific energy for a given wheel-work material combination. Thermal expansion as well as grit rubbing, while not necessarily altering the basic wear-land geometry, tend to change this force relation. Experimental results over a wide range of the machine settings and for different wheels and workpieces agree with the force relation, and the specific energy calculated therefrom coincides quantitatively with the other published results on similar workpiece materials.
Strengthening Mechanisms in High-Speed Steel as Related to Tool-Life
Authors: Henderer W. E.
Published: November 2010

Tool-life tests are reported which show that the performance of AISI M1 high speed steel taps responds to the tempering temperature in the same manner as the yield strength. The metallurgical transformations which occur during tempering are described in detail with specific attention given to the precipitation reactions which occur over the temperature range of peak secondary hardness. The variation in yield strength is found to be consistent with a coherent-incoherent precipitation sequence of alloy carbides during tempering. An estimate of the yield strength is made based on dislocation theories of martensitic and precipitation strengthening.