Hi, I am working on pneumatic structures and doing the form finding in SOFiSTiK by defining the prestress in the membrane and internal air pressure and also defining a volume inside the structure.
What I wanted to ask is:
I am changing the internal air pressure drastically and keeping other properties exactly same. Still the resulting tensile stress in the membrane remains same (Example below) -
first image is the form finding result with 0.8 kN/m2 internal pressure
second image is the form finding result with 0.4 kN/m2 internal pressure
Both have a resulting sigma of 1.83 MPa.
I wanted to see the change in the tension of membrane.
Question: why exactly the sigma not changing with changing the internal pressure (as form finding is the static equilibrium between internal air pressure and prestress in membrane).
I hope that I was able to explain my doubt.