Torsion means twisting a structural Member when it is loaded by a couple that Produces rotation about the longitudinal axis.
Consider a shaft rigidly clamped at one end and twisted at the other end by a torque T = F.d applied in a plane perpendicular to the axis of the bar such a shaft is said to be in torsion.
Effects of Torsion: The effects of a torsional load applied to a bar are
To impart an angular displacement of one end cross – section with respect to the other end.
To setup, the shear stresses on any cross section of the bar perpendicular to its axis
Assumptions made for derivation of the Torsion equation-
Pure twisting moment is applied to shaft and it acts in a plane perpendicular to axis of shaft
Material of shaft is homogeneous and isotropic and load is applied within elastic limit
Twisting moment is uniform for entire length of shaft
Cross-section of shaft remains plane after twisting
No changes occur in length of shaft
Series connection: Series connection of compound shaft as shown in the figure. Due to a series connection, the torque on shaft 1 will be equal to shaft 2 and the total angular deformation will be equal to the sum of deformation of the 1st shaft and 2nd shaft.
Parallel Connection: Parallel connection of compound shaft as shown in the figure. Due to a parallel connection of compound shaft, the total torque will be equal to the sum of torque of shaft 1 and torque of shaft 2 and the deflection will be same in both the shafts.
