Durability and fatigue

Thermoelastic stress analysis system

Full-field stress maps from an infrared camera, measured while the part is under cyclic load.

Get in touch All use cases
When it makes sense
Strain gauges show too little of the part

Strain gauges measure a few points. A full stress map makes sense when:

Hardware
What the system uses
Part Load cell Actuator frames load signal synchronized Load frame or shaker Infrared camera radiometric Industrial PC OpenEOL workflow Data acquisition load reference Stress map full field Report and database Your part System hardware
The load frame or shaker cycles the part. The camera records the small temperature change that the load causes, and the program turns it into a stress map.
The test
How the test works
  1. Mount the part in the load frame or on the shaker, and aim the camera at the region of interest.
  2. Load the part in cycles, and record the camera frames and the load signal together.
  3. Demodulate the temperature at the load frequency, and convert it into a stress map.
  4. Compare the map with the limits or an FE model, and store the result.
Software
The open-source software behind it
Your lab or lineKeeps the results
Quality database or report archiveStress maps and results over SQL, OPC UA or MQTT
OpenEOLRuns the workflow
Task engine Open sourceRuns loading and recording in sync
GUI framework Open sourceOperator screens with live data and the result
Reports and database Open sourceOne stress map for each test
AnalysisOpen-source tools in the workflow
FFT and cross-spectral density Open sourceOpenEOL functions used for the lock-in step
Stress mapLock-in at the load frequency, then the thermoelastic constant
FLife Open sourceFatigue life estimates from the stress results
DriversTalk to the hardware
pyGigEVision Open sourceInfrared cameras over GigE Vision, or other OpenEOL camera drivers
OpenEOL IO drivers Open sourceNI DAQmx for the load signal
Open-source tools such as pyGigEVision and FLife run inside the OpenEOL workflow, so your engineers can read and change every step. The program itself is built for each project on top of them.
Related use cases
Other durability tests

Vibration test tailoring

A shorter shaker test with the same fatigue damage as real use.

Details

Accelerated vibration fatigue testing

Resonance tests that track damping and stop at the first crack.

Details

Custom digital image correlation system

Full-field strain maps from cameras, instead of a strain gauge.

We can help
Planning a stress measurement?

Get in touch.

janko.slavic@fs.uni-lj.si
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