Hi, I'm a portuguese college student taking "Ortoprotesia" (our word for prosthetics+orthotics), which is basiccly a mix of health classes and mechanical and eletronic engineering classes, my "deformable systems" teacher, gave us this exercise and explained it.

I understood it and was able to solve it on m own by determinening the geometric ratios and finding the stress concentration factor from the slide, i then found the allowable average normal stress using the material allowable normal stress and the stress concentration factor, and then i applied the definition of normal stress to find the allowable load.

The teacher then gave us basiccly the same exercise but with a hole in the middle and told us to figure it out.

That's the part I'm struggling with, i looked around trying to find a similar problem, but i couldn't find any (partly because i don't know what to call this type of problem, axial loading with a hole? also, don't forget i'm portuguese and i'm not sure what the technical terms for a lot of these things translate to)

I would appreciate any help, either explaining me what to do / what to do diferently from the first problem, or directing me to some sort of website or video with a similiar problem.

Thanks in advance for any help.