Calculate Maximum Stress in Pipe AB and Rod BC Shaft

[kappcity06]

The built-up shaft consists of a pipe AB and solid rod BC. The pipe has an inner diameter of 20 mm and outer diameter of 28 mm. The rod has a diameter of 12 mm. Determine the maximum stress in the shaft.

I have stress=V/A

I picked 12N as V

and Aream I am confused

any help?

 

[PhanthomJay]

If you draw a free body diagram of the pipe that encircles A and cuts through D, what is the internal force in the pipe? If you draw a free body diagram of the rod that encircles C and cuts through E, what is the internal force in the rod? Once you determine these forces, the axial stresses follow from F/A evaluated for each piece, and then compare the two to see which is higher. You should be able to calculate the cross section areas of each piece. Note that 12N is not the corrrect force to use.