APPLICATION OF SILVER CHLORIDE IN INVESTIGATIONS OF ELASTO-PLASTIC STATES OF STRESS

摘要

The use of silver chloride as a material for photoelastic stress analysis offers the possibilities of studying both elastic and plastic states of stress in a crystalline metallike material on either a microscale or macroscale. In order to realize this possibility, however, it is first necessary to relate the stress state quantitatively with the observed relative retardation and extinction angle. In this report these relationships are developed from a general theory of stress birefringence, according to a stress-dependent hypothesis. This hypothesis and the resulting analytical relationships have been experimentally vindicated by measurements made on a variety of single-crystal specimens of silver chloride tested in simple tension in the elastic and plastic stress ranges.nWith an understanding of the relationship between the stress state and the resulting optical effects, it has been feasible to proceed with studies of relatively complicated stress states. The present work has ' included a study of the stress states in bicrystal tension specimens, in simple polycrystalline tension specimens, and in single-crystal and polycrystal tension specimens having a hole on the specimen axis. These tests, which are discussed in detail in the body of the report, have yielded qualitative and quantitative information on theelastoplastic state of stress. Silver chloride appears to be a suitable medium for photoelastic studies of the effect of plastic yielding on the state of stress in a crystalline metallike material.