Question

A shaft subjected to BM torque and axial thrust is

Answer 1

Answer:

Explanation:

14.3.1    Shafts Subjected to Torque

Maximum shear stress developed in a shaft subjected to torque is given by,

141.png

where  T          = Twisting moment (or torque) acting upon the shaft,

J          = Polar moment of inertia of the shaft about the axis of rotation

          =   142.png            for solid shafts with diameter d

           =  143.png for hollow shafts with do and di as outer and inner diameter.

r            = Distance from neutral axis to the outer most fibre = d/2 (or do/2)

So dimensions of the shaft subjected to torque can be determined from above relation for a known value of allowable shear stress, [τ].

14.3.2     Shafts Subjected to Bending Moment

Maximum bending stress developed in a shaft is given by,

144.png

where  M         = Bending Moment acting upon the shaft,

I           = Moment of inertia of cross-sectional area of the shaft about the axis of rotation

           = 145.png              for solid shafts with diameter d

            = 146.png                for hollow shafts with do and di as outer and inner diameter.

                 y     = Distance from neutral axis to the outer most fibre = d / 2 (or do/2)

So dimensions of the shaft subjected to bending moment can be determined from above relation for a known value of allowable tensile stress, [ ].