RR Moore Fatigue test is automated !

Trigger

More and more complex metal parts are produced through Additive Manufacturing (3D metal printing). Due to this production method, the material is less homogeneous, and certainly not compacted. This makes it difficult to calculate the service life under dynamic loads.

Test system

This issue has revived a classic method of testing the service life in case of metal fatigue. The concept of an RR Moore Fatigue Test (cf. ISO 1143) is based on the rotating axis principle. The specimen is loaded symmetrically at 2 points. With each revolution, the stresses in the material go through a complete cycle from pull to pressure and vice versa.

ENDUTEQ has taken up the challenge of developing a modern and innovative Test System to perform these fatigue tests. With the following principles:

• Flexible and simple test system.
• Easily test different diameters specimen.
• Reliable and reproducible testing.
• Max speed 10,000 rpm, so that in 24 hours about 15 million revolutions are realized.
• Apply weight load to specimen.

Technical challenges

Due to the high speed and number of revolutions, it is essential to choose components that will continue to work well for a long time. That is why we have opted for bearings and shaft holders (precision collets), which are often used in lathes and milling machines.

A standard solution for the flexible coupling with which the drive motor is connected to the bearing housing was not found. For this we have made a tailor-made link.

Automation test thanks to temperature sensor and slip and break detection

Accelerated aging reliably takes place if the temperature of the specimen, during the fatigue test, does not rise too much. By continuously monitoring the temperature of the specimen during the test, the speed of the specimen can be automatically reduced, at a set temperature range, and raised again at a set lower limit.

By placing bearingless encoders on the drive shaft and on the bearing housing, the speed can be measured on both sides of the specimen; if the difference between the two measured speeds becomes too great, the first rupture of the specimen occurs.

Thanks to built-in fracture detection, the test stops immediately after the specimen is broken. Now the fatigue test can be performed fully automatically.

Options

To perform fatigue tests for marine applications, the system can be expanded with a salt dropper. By dripping salt droplets on the specimen during the test, the action of rust can be taken into account in determining metal fatigue.

Such smart solutions characterize the way our company works. Are you also looking for smart custom solutions for your Test and Measurement issues? Contact us, we are happy to help you!