Learning Forum

[Danus Kilian Rawert]

Hello there.

I have developed a soft pneumatic actuator geometry with a complex design out of a hyperelastic silicone and a solid layer out of TPU material. I have done tensile tests with the silicone (but i havent measured the cross section of the rods during the test, just at the start) with this tensile test data (no further data like shear or other deformation modes) i have setup my material model for Ansys simulations. I've choosen Yeoh 3rd order and have validate the used data with a unit cube Simulation which results look similar to the tension test data. The material data from TPU comes from the manufacturer.

So I've simulated the soft pneumatic actuator with the material data. Also i have testet the actuator in real life. As i compared the simulated and real data I saw that the simulated actuator archieves more than double the bending motion compared to the real one. This could have multible reasons for sure, but due to I'm prettyy new to Ansys and FEM Simulations as well I wanted to e sure that the Simulation Setup is corretly done. Also I can not beleif that even due to multible reasons the difference is so big.

The basic setup is shown in the image below:

For the "rough" connection i used a pinball radius of 5mm; augmented-lagrange and other settings are remained defaults.
For the "no separation" connection everything default.
Analysis settings: Steps defined by time; high deformation "on"; everything else default.
Cyclic regions are 6, so its a hexogonal symmetric geometry.
If you need more setup knowledge or information please say so and I'll provide as good as I'm able to. 

It would help me a lot if someone an verify my Ansys setup or help me setting it up correctly. Many thanks in advance and kind regards,

Danus Rawert

[Danus Kilian Rawert]

One more note: In this image the pressure was just 1000 Pa, in the later used simulation i Simulate with pressures between 20 - 50 kPa.