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RESEARCH PAPERS

J. Eng. Ind. 1961;83(2):101-106. doi:10.1115/1.3664433.

Drill pipe dynamics assuming torsional and longitudinal displacements are formulated assuming that the forces which act at the bit and the sides of the pipe are random in nature. It is shown that assuming certain criteria of failure the coupling constants may be adjusted to reduce to a minimum the probability of failure.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):107-117. doi:10.1115/1.3664434.

The processes of respiration are analyzed from an engineering point of view and the requirements for resuscitator design are outlined. A review of pertinent engineering considerations is presented. Several commercially successful resuscitators are described to show their principles of operation.

Topics: Design
Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):119-124. doi:10.1115/1.3664438.

A new test method is described whereby the spinnability, i.e., the ability to undergo shear spinning deformation, without fracture, of any material may be determined. Work done to date with this test method indicates that a good nonspinning criterion for estimating spinnability is the tensile reduction of area at fracture. Results of the spinnability test suggest that a feature of this test be adopted in the design of production cone-spinning mandrels. A qualitative discussion of the effects of deviating from the sine law is presented.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):125-130. doi:10.1115/1.3664441.

With the use of an idealized model of the shear spinning process some of the basic quantities in the shearing mechanism have been defined and formulated, these being: shear strain, shear strain rate, specific energy, and tangential force (torque) in spinning. An experimental technique to study metal flow in shear spinning has been described. The results of analytical work have been compared with experimental data.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):131-138. doi:10.1115/1.3664442.

The concept of random variables as used in the theory of probability is applied to machining operations, in which the input stock, hardness, stock distributions, etc., vary. Output errors are calculated in terms of input variations and machining time, specifically for grinding operations. In particular, output size errors are related to input stock variations as well as variations of wheel sharpness. Variations in runout or ecccentricity are related to the initial runout and stock. A dimensionless variable for comparing metal-cutting machine tools is also introduced which permits an estimate of elastically produced errors. Transient forces on grinding wheels are also considered.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):142-153. doi:10.1115/1.3664446.

Three grades of nodular cast iron (60, 80, and 100) were tested to determine the cutting and feed forces required to machine the materials, to determine the performance of several grades of carbide and oxide cutting tools, and to investigate the flank adhesion phenomenon. Cutting characteristics for grade 80 and grade 100 were found to be the same as for high-strength gray cast irons with similar Bhn values. Flank adhesion, with accompanying sharp increases in cutting force values, was encountered only when grade 60 was machined with carbide tools. An attempt was made to correlate tool composition and flank adhesion.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):155-161. doi:10.1115/1.3664450.

A design of planetary-gear dynamometer or torquemeter, to measure tangential cutting forces in milling with a high degree of accuracy and sensitivity is described together with certain design considerations and limitations as well as associated force-measuring equipment. This device is a highly efficient, sensitive, and durable research tool for use in accurately determining the magnitude and manner of variation of the cutting force, energy, and power at the cutting edges of single-point or multiple-point milling cutters, as well as machine efficiency, in full-scale milling operations. Procedures and methods of determining values of tangential cutting force, specific cutting energy, and horsepower at the cutter from cutting-test data obtained with the torquemeter are given with examples.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):163-172. doi:10.1115/1.3664453.

Tool-wear and tool-life characteristics of a series of five steels of different sulfur content are presented for different values of cutting speed, feed, cutting fluid, and cold work. While the presence of manganese sulfide in steel is generally found to extend tool life, certain combinations of speed and feed yield result that indicate the reverse effect. For the group of hot-rolled steels studied, sulfur was found to shorten tool life at certain cutting speeds when the feed was in the vicinity of 0.005 ipr. The hot-rolled steels of low sulfur content exhibit better tool life with high-speed steel tools than with carbide tools when the cutting speed is such as to give a tool life in the vicinity of 4 hr. A tracer device is described that is useful in exploring the nature and extent of the crater and built-up areas on the tool face.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):175-180. doi:10.1115/1.3664456.

High-speed steel tool life results are presented and discussed for a leaded and nonleaded steel from the same heat. Variables investigated include cutting speed, feed, cutting fluid, and cold work.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):181-192. doi:10.1115/1.3664457.

Tests upon a variety of friction sliders reveal that, contrary to common belief, manganese sulfide is a poor solid lubricant relative to air. Lead, on the other hand, is found to be an excellent solid lubricant. An analog tool is introduced to enable surface finish studies to be made in the absence of feed marks. Cutting force results are presented for a wide variety of cutting conditions for both resulfurized and leaded steels. The built-up edge and thermal softening along the tool face lead to complex curves of cutting force versus speed. Additions of sulfur are found to promote the formation of a small built-up edge that is stable to much higher values of speed than that normally experienced with a nonresulfurized steel. Lead, on the other hand, tends to prevent built-up edge formation. Both lead and sulfur are found to produce thinner chips, promote chip curl, and to give rise to a shorter contact length between chip and tool. A discussion of the significance of the observed changes in contact length will be found in part 4 of this series.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):194-201. doi:10.1115/1.3664459.

Data are presented covering the effect of several variables on grinding rate for the electrolytic grinding process. The relative amount of material removal due to electrolysis and due to conventional grinding action was investigated. The Faraday current efficiency of the electrolytic part of the process was found to be near 100 per cent to the extremely high current density of 700 amps per sq in. This is thought to result from the scraping action of the wheel abrasive which prevents passivation of the work anode. Several phenomena of the process are explained on the basis of hydrogen gas pressure in the work-wheel interface. A formula is presented for calculating the hydrogen gas pressure. Equations are proposed for the basic chemical reactions of the process.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):202-206. doi:10.1115/1.3664463.

The large dynamic range to which accelerometers are subjected in a space-injection application requires that precision high “g” development studies be made. The only practical way of obtaining sustained, measurable accelerations in excess of 1g is by means of a centrifugal accelerator. The purpose of this paper is to describe the techniques which have been developed at Arma Division to process and interpret accelerometer linearity data obtained on our precision centrifuge. To do this it will be necessary to formulate a basic output equation for an inertial quality accelerometer and to point out areas of correction for some size anomalies which can occur. In addition, a centrifuge acceleration formula, corrected for earth’s rate, is developed. Interpreting this formula leads to the possibility of measuring earth’s rate with an accelerometer.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):207-213. doi:10.1115/1.3664464.

Pressure and temperature calibration of ultrahigh-pressure apparatus is described. Pressure calibration up to 30 kilobars has been established accurately. Above this pressures are not known with sufficient absolute accuracy to compare results reliably with theoretical predictions of behavior of matter. The effect of pressure on temperature-sensing devices, like thermocouples, have been measured over temperature intervals of 100 deg C up to pressures of the order of 100 kilobars. The effect on some thermocouples is appreciable.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):215-218. doi:10.1115/1.3664467.

An idealization of a cylindrical pressure vessel with end plates fastened by longitudinal bolts is considered. The initial axial preload is restricted to be below the load necessary to begin plastic flow and the bolting is assumed elastic throughout the application of pressure. The elastic solution is obtained and the plastic solution may be found by a numerical integration. An illustrative problem is included.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):219-226. doi:10.1115/1.3664468.

Using elementary apparatus and instrumentation, shaft whirling has been investigated for three cases involving round or flattened shafts in combination with uniform or asymmetric stiffness bearing supports. The type of whirl observed varies with the combination of asymmetries used. Single and double-frequency whirls have been noted, both forward and backward with respect to shaft rotation. Studies of the phase-angle changes required by the running conditions have indicated the reasons for whirl direction and frequency.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):227-232. doi:10.1115/1.3664471.

The most efficient spring, for a given application, is one that safely stores the required amount of energy and uses the least possible material. Springs designed to this premise are said to have minimum weight. Several analytical procedures, based on prescribed initial assumptions, are already available to the designer which permit the calculation of certain minimum-weight springs. In some instances the assumptions are not entirely relevant to the problem at hand; in which case, a true minimum spring is not obtained. This paper presents a solution to minimum-weight springs based on initial assumptions which can be more universally applied. Also, a solution is given to the ultimate condition where no design variables (outside diameter, wire diameter, spring index, load rate, solid height, or number of coils) are chosen arbitrarily.

Commentary by Dr. Valentin Fuster

DISCUSSIONS

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1961;83(2):117-118. doi:10.1115/1.3664436.
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Abstract
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster

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