All posts by betavibn01

When life gives you lemons, Make lemonade!

We all know that getting good vibration Data is critical in order to properly assess assets health.

But what happens when the measured process involves transient behaviour reflected in the dynamic signature? Is it possible to isolate the transient behavior and quantify it? How to insure measurement repeatability to be certain we are comparing apples to apples in our trends and exceptions?

The following measurement reading (1mn taken for this case study) was measured on a bar mill where the normal behavior is highly transient. And in this case vibration was coming from two distinct sources, involving two frequency ranges, during different time frames.

Using BETAVIB Technology embedded in VibWorks, we were able to demonstrate this behavior: Using STFT Spectrogram allow to combine the time and the frequency domain to properly understand WHEN events are happening and WHERE they are happening.

 

Using conventional tools, with no consideration of sources/process contribution to the vibration signal will lead inevitably to incoherent trends with vibration is measured under different operating conditions.

BETAVIB technology will be again useful to isolate and extract vibration sources and evaluate their contribution in the measured signal.

 

Time waveforms extracted from each source can be analyzed separately, and vibrations parameters calculated with being perturbed by the other source, Overall’s, spectrums, Demodulation spectrums …

Using this detailed knowledge of your asset dynamic behavior will help you built automated measurement packs to monitor each source separately, Track their contribution to the signal and have your VibWorks workstation handle alarm crossing and deal automatically with exceptions on these complex cases.

So when life gives you lemon

[a machine with variable behavior every 4 to 8 seconds]

Make lemonade

[Use powerful technology to do the job PROPERLY anyway]

 

ONLINE CONDITION MONITORING FOR ASSTETS OPERATING UNDER VARIABLE OPERATING CONDITIONS

Challenge :

Online condition monitoring of machines operating under variable speeds and loads, requires a special attention. Variation in speed or load has an impact on the vibration response, and consequently, this could hide potential faults easily detected in steady regime. Change in shaft speed imposed by the process causes considerable distortion in the vibration spectrum so that the signatures of a given fault become very difficult to identify. Moreover, transient operations could result in a significant vibration amplification despite the non-critical state of the installation -due to natural frequencies crossing-. In fact, this effect could be very harmful for an online condition monitoring system -false alarms- if the latter haven’t been designed to consider such changes in operating parameters.

Continue reading ONLINE CONDITION MONITORING FOR ASSTETS OPERATING UNDER VARIABLE OPERATING CONDITIONS

No excuses for High Vibrations: proof by the numbers

In this article, we will be borrowing a slogan from our partner LUDECA  and put it in numbers.

It’s admitted that vibrations affect the useful life of mechanical components, roller bearings being among the most important ones due to their impact on assets uptime in case of failure.

The following process defines the parameters involved from Excitation to life expectancy:

Force => Vibration => Load => Strain => Fatigue => Reduced Life

Continue reading No excuses for High Vibrations: proof by the numbers