Pressure simulation without fixtures

Hi all,

Is there anyway I can apply pressure on the inner surfaces of my tank/container/chamber without applying any fixtures?

What I'm looking for is where I'll be applying air pressure (1.5bar) into my chamber while it sits on a table, not bolted to the ground or anything...

I'd like to see the resulting deformation.

However it seems like most online tutorials go through the Fixtures --> Fixed geometry route.

Thanks

SolidworksSimulation