抄録
On the stress determination of machine parts, it is necessary for us to know not only tensile stress but also compressive stress. Of the tensile stress determination by brittle coating we have reported in the previous paper. For measuring compressive stress, we utilized the phenomenon that the coating on the surface of machine parts under load relaxes within an hour. That is, the machine parts are loaded in compression and during this condition is maintained the relaxation proceeds in the coating. After the duration of about 50 minutes the coating becomes free from stress. On leaving the load, the machine parts tend to revert to the initial condition and then the tensile stress occurs in the coating. Thus minute cracks break out in the coating as in the case of direct method (tensile stress determination). The mode of qualitative as wel las quantitative analysis of compressive stress is analogous to that in the case of tension. A few of examples experimented are shown.
