Therefore, if the torque and the degree of rotation are known according to the experimental
result, the shear stress and the shear strain can be determined from equations 2 and 4. The obtained
information is then used for the construction of the graphical relationship between the modular shear
stress (16MT/aD
3) and the shear strain (θr/L) as illustrated in figure 7. The curve is somewhat similar
to those typical stress-strain curves tested under tension, giving elastic and plastic ranges with respect
to the torsional stress applied.