Description

The purpose of this experiment is to analyze and determine the rigidity modulus of the various metal rods.
You will investigate;

• The modulus of rigidity (or shear modulus) of the materials,
• The shear strain (the angle of the shear) on the outer surface of the metal rods,
• The relationship between the torque and the twist angle.

The torsion apparatus is used to determine the modulus of rigidity (shear modulus) of the metal rods. When under application of an external force, the shape of a solid material changes without change in its volume and the solid material is said to be sheared. The shear modulus (rigidity modulus) at the end of a solid circular rod as a function of the mass (load) is given by;

Here, M is the hanging mass, g is the acceleration due to gravity, R is the radius of the wheel on the torsion apparatus, is the length of the metal test rod over which the angle of twist is measured, is the radius of the circular shaft and θ is the angle of twist in radians.