A Basic Study of the Plastic Strain Freezing by Photoplastic Experiment

It is difficult to solve the problem of stress-strain distribution in plastic regions in comparison with elastic bodies. Thus, an attempt to expand and apply stress- strain analysis by photoelasticity, with regard to polycarbonate resin in plastic photoelasticity, has been promoted so far and many significant achievements have resulted therefrom. This study is an examination of the possibilities of the plastic strain freezing method in comparison with the elastic stress freezing method. First, we attempted to determine the best temperature for plastic strain freezing. Further, it became apparent from systematic experimental results that it is 'strain' and not 'strain' which is frozen in plastic regions. In other words, it was made clear that the Birefringence N in strain freezing was proportional to difference in the principal strains (ε1-ε2).