Unit 4-Theory of Torsion

Which of the following is an assumption in the theory of torsion?

• Material is brittle

• Material is homogeneous and isotropic

• Shaft is subjected to axial loads

• Shear stress is constant across the section

In torsion theory, it is assumed that plane sections:

• Become curved after torsion

• Remain plane after torsion

• Break apart under shear

• Change shape randomly

Torsion theory assumes that the shaft is subjected to:

• Pure bending

• Pure twisting moment

• Axial compression

• Lateral loading

The assumption that the shaft material obeys Hooke’s law implies:

• Plastic deformation

• Elastic deformation

• Permanent deformation

• No deformation

The torsion equation is given by:

• T/J = τ/r = Gθ/L

• T/J = σ/r = Eθ/L

• T/A = τ/r = Gθ/L

• T/J = τ/r = Eθ/L

In the torsion equation, ‘G’ represents:

• Young’s modulus

• Shear modulus

• Bulk modulus

• Poisson’s ratio

The term ‘θ’ in the torsion equation represents:

• Shear strain

• Angle of twist

• Torque

• Radius of the shaft

The polar moment of inertia (J) in the torsion equation is maximum for a:

• Rectangular section

• Circular section

• Triangular section

• Square section

The maximum shear stress in a solid shaft occurs at:

• The center of the shaft

• The outer surface

• Halfway between center and surface

• Uniformly across the section

For a hollow shaft, the maximum shear stress occurs at:

• The inner surface

• The outer surface

• The mid-thickness of the wall

• The center of the shaft