Hello Andrea,

I’m looking at your model now, and thinking about ways to simplify the meshing.

The Inextensible layer has many holes. What is the function of the holes?  Can the holes be eliminated from the geometry?

The inextensible layer is very thin. Could this thin solid layer be replaced with a surface model?

In pink are the cavities where the pressure is applied. In Static Structural, there is only pressure applied to the top side of the wing, is that to get it to change shape?

I noticed Frictionless contact used. Friction can help convergence. However, that won’t fix the highly distorted element error. Better element shapes may be what is needed.

One reason models fail to converge is due to mistakes in the material properties. Here is the Ecoflex 00-50 properties entered in the model.

Those numbers seem way too small. Were they entered in the wrong units and are off by a factor of 1 million? This would be the cause of the immediate error messages of highly distorted elements.

I found a Masters Thesis on this material. This has good information and you could use this Mooney-Rivlin data.

If you would like to discuss this further, I can set up a meeting where we talk and share our screens. I’m in the Eastern US Time Zone.