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With the development of human history, technology is gradually
developing breakthroughs. One of the most important periods that opened
up the early beginnings of the modern era was the industrial revolution.
During this time, the machinery industry has been formed, contributed an
important role in supporting production activities. Machinery allows
production of a variety of items. It is not only speed performance but also
high efficiency beyond the human ability. In addition, machines perform
better in long-term jobs and achieve higher consistency. The quality of
work can be changed when human is influenced by emotional factors,
health, etc. In addition, the machines help to carry out various dangerous
tasks on behalf of humans. The machines are widely used in various fields
such as: manufacturing, construction, agriculture, industry, mining, .
Today, many machines are even designed to operate without controlling
human. With the support of machines, the world becomes more
modernizing and growing. Particularly in the context, the industrial
revolution is developing on the world and affecting to the global economy.
The research, manufacture and enhance longevity and ability to work of
machinery that has contributed significantly to the industrial revolution.
Shaft is one of the most important parts in machine. The Shaft is
used to transmit torque and rotation from a part to another part of the
machine through other machine parts assembly on the shaft such as the
gear, belt, key, shaft couplings. The characteristic movement of shaft is
rotary motion. During operation, the shaft is subjected to torque induced by
the engine or system to the transmission shaft [21], [22], [25], [26], [28],
[35]. In particular, the shafts and other components are generally made of
elastic materials. So under the influence of torque, the axis will be
subjected to twisting. This deformation is changed over time and repeated
at each rotation cycle of the shaft that is called shaft oscillation. This
oscillation is particularly harmful, undesirable. It is cause of fatigue
damage and effects to the longevity and workability of the shaft and
machine [21], [22], [25], [26], [ 28], [35]. Specifically, this deformation is
cause of the vibration, machine noise, and fatigue damage of shaft. It
effects not only to the shaft itself, but also damages other important
machines mounted on the shaft. Thereby it induces damaging of the
machine. The study to reduction of shaft vibration is an important and
timely task [21], [22], [25], [26], [28], [35].
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