Transactions of the American Institute of Mining and Metallurgical Engineers (Incorporated). Volume 62 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1920 Excerpt: ...which the loads, as described by Professor Lanza,7 "were so applied, that a certain portion, greater than 10 in. in length, was subjected to a uniform bending moment." Professor Sondericker's investigations8 included "the determination of elastic changes, resulting from repeated stresses, and the influence of such changes in producing fracture." Regarding the results, it was stated that "the effect of rest is to decrease the amount of set. In most cases, however, the set lost is soon regained, when the bar is again subjected to repeated stress, especially in the case of the harder steels." For the Watertown laboratory equipment, a high-speed DeLaval steam turbine was procured, in order to conduct tests at speeds approaching vibratory movements; some 500 or more rotations per second. A rotating shaft appears to afford the only opportunity for conducting tests at high speeds in which acceleration of the mass of the specimen 'Gaetano Lanza: "Applied Mechanics," 534. New York, John Wiley & Sons, 1910. "Jerome Sondericker: A Description of Some Repeated Stress Experiments. Technology Quarterly (1892) 5, 70; Repeated Stresses. Op. cit. (1899) 12, 5. does not interpose as an obstacle to attaining a uniform distribution of the loads. High-speed tests conducted in this manner become introductory to tests on impact, and were so intended. There are two phases to be considered in tests on impact, one having to do with elastic movements not involving permanent sets, and one in which permanent sets are involved and constitute the major effects. The writer's severance of his connection with the Watertown laboratory brought these contemplated tests to a close. The testing apparatus was dismantled soon thereafter and it is be...