Studies on a Photo-Elastic Method Fixing Stress Patterns at Room Temperature

Abstract

The usual method of freezing photo-elastic stress patterns is to heat the specimens first and then cool them down very slowly without disturbing the stress patterns obtained at the high temperature. However, if a method which fixes stress patterns at room temperature could be developed, the method would be more useful. For instance, it could be applied to the study of the distribution of stresses in an object placed in a flow, such as a model in a wind tunnel.
In this paper, an experiment which fixes stress patterns at room temperature during the curing process of resins was studied.
The summary of the experimental results is as follows;
(1) The fringe patterns fixed by this method show good coincidence with those obtained by ordinary photo-elastic experiments.
(2) The fringe order is proportional to the principal stress difference in an elastic body.
(3) The linear relation between the load and the fringe order is retained for a wide range of loads.
(4) The fringes are not disturbed by cutting the specimen.
Therefore, this method, as well as the heating method, can be used for the three-dimensional analysis of stresses.