Is there any example of high frequency vibrations more than 40Khz.(with calculation please.) . i need at-least 2 or 3 examples.
Your request is not something that most people are involved with....most machinery vibrations occur way below 6khz, the range you are requesting belongs in the "ultrasonic" range, typically ultrasonic equipment measures this frequency range.
If no vibration generates with such high frequency then why the Instrument Manufactures gives instruments with frequency ranges upto 40 khz, 80 khz(for vibration). Are they fooling US?.
Ultrasonic evaluation in the 20-100khz range, is used for air leak surveys, steam traps, lubrication, bearings etc.
Your statement "instrument manufacturer" encompasses millions of pieces of test equipment. Some people maybe using an instrument/data collector to identify frequencies in this range, but there would be a very small number of people doing this. Example, jet engine turning 26,000 rpm with 200 individual blades on one rotor, 26kX200/60=86,666hz/86khz or 5,200,000 cpm
No one is trying to fool you, just depends on how you are applying the technology/tool to the job at hand.
Hope this helps