There
is an object that changes its position and repeatedly moves back and forth
around a certain standard. On the other hand, there are objects that end with a
single push or pull. Which one takes more strength? If you look closely at the
fitness equipment nearby in your daily life, you will see that what you moved
with effort must be returned to its original position before you can apply
force in the same direction in the next exercise. In fact, which force is
applied is not that important when comparing two movements. However, the key is
how much greater force is applied and how often. We understand that all
physical waves appear as noise in the air and as vibration (repetition) in
objects. And if you draw it as a two-dimensional graph, it can be expressed
directly as the X and Y axes. This is ‘change in size over time’.
X and Y axes of vibration
The X~~~
|
Y axis |
Main unit |
Displacement (µm, mm), velocity (mm/s,
cm/s), acceleration (m/s², G) |
|
Sub
unit |
0-peak, peak to peak, rms |
The ‘Z’ axis (third axis)
can be used to express the amplitude of vibration, and it mainly plays the role
of RPM in Campbell, Waterfall, etc.
Unit of vibration,
amplitude unit, displacement speed acceleration, rms, peak, vibration energy,
amplitude …….. www.kCBM.kr, https://blog.naver.com/vs72 , https://contents.premium.naver.com/bisope/visope
다음으로 진동의 Y축은 대체로 주단위, 부단위로 혼합하여 표현하는데 주단위는 (변위, 속도, 가속도)로 부단위는 (0-peak, peak to peak, rms)로 한다. 단위의 다양함과 혼용은 관찰의 용도나 기준 등이 또한 다양하기 때문으로 예를 들어 저주파 거동의 파이프는 변위 P-P 고주파 거동 베어링은 Grms로 표현하는 것이 관찰의 용도가 파괴나 수명에 대한 대비책인 모니터링에 가장 잘 맞기 때문이다. 혼용의 예) 2.4mm/s 0-p, 50µm p-p, 1.2G rms
진동의 진폭표현으로 ‘Z’축(제3의 축)을 활용할 수도 있는데 주로 Campbell, Waterfall 등에서 RPM의 역할 등을 담당하게 된다.
