TENSION TEST ON MILD STEEL ROD
To conduct tension test on the given mild steel rod for determining the yield
stress, ultimate stress, breaking stress, percentage of reduction in area, percentage
of elongation over a gauge length and young’s modulus.
Universal Testing Machine, Mild Steel Rod, Vernier caliper/Scale.
The tensile test is most applied one, of all mechanical tests. In this test ends of
test piece and fixed into grips connected to a straining device and to a load
measuring device. If the applied load is small enough, the deformation of any solid
body is entirely elastic. An entirely deformed solid will return to its original form
as soon as load is removed. However, if the load is too large, the material can be
deformed permanently. The initial part of the tension curve, which is recoverable
immediately after unloading ,is termed as elastic and the rest of the curve, which
represents the manner in solid undergoes plastic deformation is termed as plastic.
The stress below which the deformation is essentially entirely elastic is known as the
yield strength of material. In some materials the onset of plastic deformation is
denoted by a sudden drop in load indication both an upper and a lower yield
point. However, some materials do not exhibit a sharp yield point. During plastic
deformation, at larger extensions strain hardening cannot compensate for the
decrease in section and thus the load passes through the maximum and then begins
to decrease. At this stage the “ultimate strengths”, which is defined as the ratio of
the load on the specimen to the original cross sectional are, reaches the maximum
value. Further loading will eventually cause „nick‟ formation and rupture.
Usually a tension testis conducted at room temperature and the tensile load
is applied slowly. During this test either round of flat specimens may be used.
The round specimens may have smooth, shouldered or threaded ends. The load on
the specimen is applied mechanically or hydraulically depending on the type of