Hillman, Victor E.
Director of Research, Crompton and Knowles Loom Works, Worcester, Mass.
Pages: 3 Published: Jan 1950
The tests reported herein were undertakes by Crompton & Knowles Research Laboratories to obtain information on cast iron which had not previously been available. Before the advent of SR-4 strain gages, the determination of stress-strain relationships for cast iron was not practical for the average industrial laboratory. Any of the procedures which would give sufficiently accurate results were long and delicate and required costly equipment. When it is considered that elongation values for cast iron are less than 1 per cent in 2 in., it is not difficult to visualize the extreme accuracy required in measuring the strain produced by loads considerably below the ultimate strength. Moreover, most laboratories could not justify the time involved in making determinations, nor could they risk the damage to valuable extensometers if a specimen fractured prematurely during the process of testing. SR-4 strain gages made it possible to plot complete stress-strain diagrams for the various cast irons, such as those used in loom construction. In addition, the use of these gages resulted in obtaining more reliable values for the modulus of elasticity and the extent of its variation in irons of different composition. Such information was necessary to facilitate proper cross-sectional design and the development of maximum longevity in loom components.
Paper ID: STP48077S