Strength of Materials

6.10 COMBINED BENDING AND TORSION

A shaft transmitting torque or power is not only subjected to shear stresses but also to bending moment due to self-weight of the shaft, pulleys and couplings and due to the pulls exerted by belts and rope drives (Figure 6.5).

 

 

Fig. 6.5

 

Thus, at any point in the shaft, the component of stresses are:

1. the shear stress due to torsion,
2. the bending stresses (tensile or compressive) and
3. shear stress due to other forces causing bending.

Out of these three component of stresses, (i) and (ii) are important. Further discussion is made on these aspects.

A shaft as shown in Figure 6.6 is considered. Let D be the diameter ...