In this paper, bars having a stringer of metal sheet in the central line, and semi-circular or V-notches on both sides are investigated photoelastically. The bars are made of epoxy resin and stringer of metal sheet (duralumin or copper), which are bonded together with Araldite 121. The bars are experimented under tension with the simple polariscope. The radii (or depths) of these notches of the bars are varied in several values. Consequently, several interesting results are obtained. And then the problem of reinforced bars having a reinforcement of different materials is studied.