I'm currently researching the strength of domes underwater and I went down the rabithole of material science. The basics of this research (or though experiment) is to bring a dome filled with air to the seafloor and see if it implodes or not. The specifics are as follows.
The dome is 3D-printed Outer Diameter: 10 cm Inner Diameter: 8 cm (so the thickness of the dome is 1 cm) (this can vary) Material: PLA
QUESTION: What is the maximum amount of pressure this dome can take before it breaks?
I've already found the following data from this source
Properties PLA: - Impact strength: - STD: 1.8 ft-lb/in - MAX: 4.1 ft-lb/in - Compressive Strength - STD: 2600 PSI - MAX: 13600 PSI - Tensile Strength - STD: 6783 PSI - MAX: 9531 PSI - Flexural Strength - STD: 8970 PSI - MAX: 13731 PSI
It seems likely that I'll be needing the compressive strength here, because the theoretical dome is being put at the bottom of the theoretical sea. It's going to be compressed. But these numbers have very little context (at least for me, I don't have an engineering degree). I mainly worry about thickness. In my mind, when a wall is thicker, it means it can hold more weight, can withstand heavier punches and generally breaks less easily. I don't see this reflected in this number. It also doesn't take the shape of the object in mind. A sphere is supposedly stronger then any other shape (I found this cool site selling dome bunkers). But this too doesn't seem reflected in the compressive strength value.
It might also have to do with the size effect, but that seems to weaken - not strengthen - structures and would only be applicable if I made the outer diameter variable.
If anyone can help me any further it would be very much appreciated. I really want to make clear that I'm not asking you to do my homework (this isn't really homework, but still). Pointing me vaguely in the right direction is also extremely helpful. Thanks in advance!