Hello!
If anyone can help me with data on the stress supported by bismuth telluride (Bi2Te3) legs in thermoelectric generator applications (published papers or manufacturer data or anything specifying the supported stress).
I am aiming to harvest heat from industrial rotary bladed machinery (screw compressors, gas turbines), which also exhibit vibrations. I have conducted some simulations with TEG module in COMSOL Multiphysics (stress result ~1.3 kPa) and I would need reference data to know if my TEGs are able to withstand mechanical stress, especially on the transverse directions of van der Waals bonds.
For reference, this is the TEG model I purchased https://www.tegmart.com/thermoelectric-modules/10w-teg-module.
Many thanks in advance!
Claudia,
I suspect that the interfaces of the junctions will be the weakest part of the device - the joints are either soldered or metallized in some way - and without snapping a few TECs it's hard to know how to characterize 'em.
I'd be tempted to buy direct from a manufacturer, buy at least half a dozen or so, and simply vibrate the proverbial heck out of them: bolt them to shake-tables, and see how they fare.
My suspicion is that you'll see failures in the wires connecting the TEC to a terminal block before you see failures in the TEC itself. Or, perhaps in the glue-line between the TEC and the machine - if you're using an adhesive.
Wonderful idea, James Garry ! I love destroying things too! Too bad I only got three TEGs and I cannot afford to do destructive tests just yet haha.
Ohh noo... you? Empirical? Naaah!
(my doctoral professor says being empirical is one of my worst traits that he cannot handle haha!)
Yes, you are correct, the junctions are the weakest part of a thermoelectric module, and also the maximum stress seems to be on the edges of the exterior ceramic plates (hot and cold sides). The legs themselves are not subjected to much stress.
Also, I read that von Mises analyses won't work for TEGs since it regards sinusoidal (shear) waves, and TEGs should be analysed with linear forces perpendicular to the van der Waals bonds.
I concluded that since the TEG would be actually subjected to sinusoidal vibration on any rotating machinery, I have nothing to worry about and in this case the von Mises stress analysis is all I need!
Also, I found these properties in the attached article.
Chapter Mechanical Properties of Thermoelectric Materials for Practi...
Thank you very much for your answer!
Best regards,
Claudia
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