Systematic detection of defects by vibration measurements

The Challenge

Problems related to acoustics and vibrations often occur in complex environments. Standard solutions available on the market do not always answer these problems. Metravib brought its expertise to support a project and helped design and develop a customized solution.

A historical customer of Metravib submitted a specific quality control issue encountered during the vibration control carried out at the end of the production line. Some equipment were compliant with their initial control method but were not compliant regarding specific requirements set by final customers expecting a higher level of quality.

To meet these new requirements, we were given precise specifications:

• The control time of a part must be less than 100 milliseconds
• The rejection rate must be 0.5% maximum with 100% detection
• The tool must adapt to different production lines and different product ranges.

Solution

To meet these challenging specifications we have implemented a specific method based on spectral analysis that allows it to be independent of the test configuration (test bench, rotation speed).

The proposed method allows to precisely highlight the frequency emergences, characteristic of defects that can show-up for this kind of parts.

At the end of the experiment, with a simple measurement of vibration levels, we can identify if the part is defective or not. This significant improvement of the previous test procedure now allows us to successfully meet new requirements!