| dc.description.abstract | Tensile test is one of the ways to study how strong a material. By leaving the damaged
procedure, tensile test tend to be more accurate to compare it to other similar hardness test.
The most of important in mechanical testing is techniques of strain measurement. A several
of technique exists for measuring strain in the tensile test such as by machine crosshead
motion and extensometer. These technique has its own advantages and disadvantages.
Apart from the experiment using Universal Testing Machine, the Finite Element Analysis
method (simulation) was also used to study the mechanical properties of mild steel.
Demand for the measurement accuracy and the different in changes in elongation for this
mechanical properties testing will be investigated. This comparison base on the mechanical
properties of material according modulus of elasticity, ultimate tensile strength, yield
strength and percentage of elongation. In this experiment, the average of Elastic’s modulus
is 24.47GPa, Yield’s strength is 306.67MPa, and elongation is 22.33mm. The machine
crosshead motion showed high variability in the strain measurement. The Elastic’s modulus
values were not in acceptable range. Therefore, the machine crosshead technique is not
used for modulus measurement techniques. From the stress-strain graph it is understood
that the mild steel follows the Hooke’s Law (elastic linear line). For the example, stress is
directly proportional to strain. After the linear region in the graph, there occurs necking on
the specimen and finally it breaks. In finite element analysis’s result, parabolic type is more
appropriate for data. Percentage of estimated global error for parabolic is lower than linear,
which is 5.163% and 9.016% respectively. The comparison between experiment and
simulation is slightly different of the results. This is because affected by several factors
such as temperature, crosshead motion, placement the specimen at gripper (Universal
Testing Machine), and the composition of the mild steel. Therefore, even if the same ty e
of material and the same size that can result will be different. | en_US |
