On Poisson's Ratio of Cast Iron

Abstract

In this paper, the authors describe the results of study on Poisson's ratio of cast iron. For cast iron, it is not ordinarily easy to make a perfect flat surface so sufficient as to be adaptable to the interference measurement. Therefore, the authors intend to improve this method to be applicable to the case where a slight convexity in the polished surface is permitted. They were able to improve the results of ordinary method by measuring the translation of fringes due to variation of load and by calculating convexity and obtained the more correct value of Poisson's constant by this method. They confirmed experimentally that this material constant varied according to internal stress and discussed this problem comparing with the results of NAKAGAWA's theory for non-linear elasticity.