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1.
TITLE
Torsion Test
2.
ABSTRACT
The following lab practice outlines the proper procedure to determine the modulus of
rigidity of mild steel. Solid cylindrical mild steel was subjected to a torsional load until
it experienced fracture. By measuring the applied torque and the angle of twist, a graph
of torque against the angle of twist can be plotted. Through the graph, we can observe
the
elastic and plastic behavior of the specimen before fracture. The modulus of rigidity,
G also can be determine through the straight line plotted in the graph. The error in the
experiment can be calculated by using the experimental and theoretical value of G.
3.
INTRODUCTION
Torsion is an important structural action that increases member shear strength. It occurs
when it is twisted causing twisting force acting on the member, known as torque, and
the resulting stress is known as shear stress. This stress is added to the existing shear
stress due to vertical and lateral applied loads. The design of members to resist the
torsional shear stress depends on the rigidity of the member cross section. Therefore,
edge beams should consider torsion in their design. Vertical members such as columns
and shear walls should be designed to resist dynamic loadings such as earthquake and
wind. The importance of considering the extra shear stresses caused by torsional actions
will provide stability and resistance against structural failure.
Figure 1 : Torsion test
The purpose of torsion testing usually parallels that of uniaxial tension tests. Torsion
testers or torsion test machines measure the torsional strength, stiffness and stress strain
properties of materials and products. Torque measurement unit with a torque digital