1993 年 13 巻 1-2 号 p. 1-6
This paper elucidates the mechanism of formation of the data-curves and their properties. The curves are the loci of the unit polarization vector s (i, 0) plotted on the Poincaré sphere. The reason why a curve bends sharply under a certain condition is clarified, and an example of such phenomenon caused by the uniform rotation of the secondary principal stresses is described in detail.