I have a beam question, that I can't seem to find a right answer for.
Consider a squere hollow profile of say aluminum, height 7 cm and width 3 cm. It can carry a certain weight as a girder. If I want to compare this profile with a hollow tube with the same wall thickness. Is there a rule of thumb that says what the radius should be to carry the same weight?
So how much does the cylindrical shape contribute to it's bearing capacity
Study area moments of inertia. You will get the answer to your question.