AN APPLICATION OF COMPUTER IMAGE-PROCESSING AND FILM REPLICA TECHNIQUE TO A NICKEL FOIL STRAIN GAGE

摘要

The elastic stress of a specimen subjected to repeated loads is measured by a microscopic observation of slip-bands in nickel foil bonded to the surface of the specimen. The relation between the stress amplitude and the density of slip-bands in the foil is examined at various temperatures. An image-processing system using a personal computer is applied for an automatic measurement of the density of slip-bands in the bonded foil. The density of slip-bands replicated in a plastic film is also measured by the image-processing system, and it is in good agreement with the density of the original slip-bands, The peak stresses in grooved shafts under bending are measured using the nickel foil gage and the image-processing system. It is found that the results are satisfactorily accurate. [References: 6]