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RESEARCH PAPERS

J. Eng. Ind. 1962;84(2):197-202. doi:10.1115/1.3667451.

This paper develops a theory for the determination of the plastic pressure-deformation relation in a thick-walled cylindrical pressure vessel subjected to internal pressure and made of an anisotropic material. In this theory, large or finite strains are considered and a closed solution is found for the pressure-strain relation based on a modified log-log tensile stress-strain relation. Theory is also developed for predicting the maximum pressure which the vessel can withstand.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):205-216. doi:10.1115/1.3667455.

This paper is concerned primarily with the effects of external pressure on thin-wall torispherical, toriconical, and ellipsoidal pressure vessel heads including the determination of the collapse pressures. Two test vessels, one having torispherical and 120-deg toriconical heads and the other having ellipsoidal and 90-deg toriconical heads, were used in the study. Longitudinal and circumferential stresses per psi external pressure were plotted for the regions at which the vessel heads had been welded to the cylindrical portions of the vessels. Deflection values were plotted for the torispherical and ellipsoidal heads. Both the stress values and deflection values were determined from experimental data.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):220-224. doi:10.1115/1.3667462.

The theory of a previous paper which was designed for nonhardening plastic deformation of simple and compound cylinders in axisymmetric generalized plane strain is extended to include linear strain hardening in the plastic range. The method, which is limited to small strains, uses a modified Tresca yield condition and assumes incompressibility for both the plastic and the elastic ranges.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):225-234. doi:10.1115/1.3667463.
Abstract
Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):237-246. doi:10.1115/1.3667467.

New apparatus suitable for compression creep tests of slender specimens is described. The apparatus is designed to prevent buckling and to introduce a minimum of friction. Results are reported for tension and compression creep of polyethylene and annealed, unplasticized polyvinyl chloride copolymer at 75 deg F and 50 per cent relative humidity. The stress σ, strain ε, time t data from these tests were found to be describable with reasonable accuracy by the equation

ε = ε0 sinh σ/σε + mtn sinh σ/σm
where ε0, m′ , n, σε , and σm are material constants. The results for polyethylene show that the creep in tension and compression were virtually the same. However, the creep in tension was similar but larger than in compression for polyvinyl chloride. These observations are interpreted in terms of the material structure and the influence of the normal stress on active shear planes.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):248-264. doi:10.1115/1.3667471.

The application of centrifugal compressors to the handling of gases in the process industries is of increasing importance. The problems associated with performing tests at the manufacturer’s plant under process conditions and the lack of a universally accepted method of performance correlation are matters of concern. This paper presents a recommended correlation procedure evolved from the review of technical papers embracing aspects of the subject. A program for the free interchange of air and process test data between manufacturer and user is submitted. This recommended procedure and proposed program (1) provides designers with essential information previously unavailable to them, and (2) ultimately benefits the user by the production of higher-performance machines.

Commentary by Dr. Valentin Fuster
Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):282-288. doi:10.1115/1.3667473.

To determine the effects of cutting conditions on flank adhesion, nodular cast iron grade 60 was machined dry and wet with carbide cutting tools K6, cast iron cutting grade, and K4H, steel cutting grade. Decreasing the feed rate raised the critical cutting speed at which flank build-up occurred and lowered the resultant tool force. For tools with positive rake angle, the critical cutting speed was generally higher and tool forces were lower than for tools with negative rake angle. A clearance angle of 15 deg eliminated flank adhesion, as did the use of cutting fluids. Flank build-up was analyzed chemically and metallurgically. Methods to prevent flank adhesion are recommended.

Commentary by Dr. Valentin Fuster
J. Eng. Ind. 1962;84(2):289-299. doi:10.1115/1.3667477.

This paper is a summary of recent manufacturing experience with molybdenum-0.5 per cent Ti sheet material. This refractory metal is new to industry, it is needed for high temperature vehicle application, and its fabrication characteristics differ significantly from other common airframe metals. The paper presents manufacturing development test data and production experience from forming, trimming, and edge finishing of moly-0.5 per cent Ti material. It describes techniques, equipment, and procedures for “hot” forming moly-0.5 Ti. It provides recommendations for trimming moly and it suggests suitable methods for edge finishing production parts.

Commentary by Dr. Valentin Fuster

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