Please help explain question A would the maxium stress condi

Please help explain question

A) would the maxium stress condition for a cantilever beam be largest at the neutral axis rather than outer surface in what conditions and why?

B) in stress design the phenomenological failure theory for cast iron part, what method would you use and. Why?

Solution

A) At the neutral axis the resultant force is always zero as the tension and compression forces balance each other. Hence the stress would be maximum at the outer surface than in the neutral axis for a cantilever beam.

B) Since the cast iron is a brittle material, the normal stress hypothesis can be used.