Register now or log in to join your professional community.
the question is to be rephrased,the hollow rod is stronger than the solid rod of the same solid material , that shall make the hollow rod of bigger diameter and consequently larger moment of inertia around its central axis yielding larger resistance
because of bigger inertia than steel rods which consume same quantity of material
Hollow pipe have more anertia than the solid pipe
Hollow steel pipe has higher strength to weight ratio than solid steel rod of same cross section.
Most of the strength of a cylinder comes from the outer portions. I think the contribution goes like the cube of the radial position. So, if you took a solid rod and drilled out a half the volume from the center, you do not lose half the strength. Strength to weight ratio is better for a hollow pipe than a solid rod.
because the moment of inartia of the member depends on the depth of the beam not the wheight while the weight will make more sttlement
