A prismatic bar of diameter d0 = 20 mm is being compared with a stepped bar of the same diameter (d1 = 20 mm) that is enlarged in the middle region to a diameter d2 = 25 mm (see figure). The radius of the fillets in the stepped bar is 2.0 mm.
(a) Does enlarging the bar in the middle region make it stronger than the prismatic bar? Demonstrate your answer by determining the maximum permissible load P1 for the prismatic bar and the maximum permissible load P2 for the enlarged bar, assuming that the allowable stress for the material is 80 MPa.
(b) What should be the diameter d0 of the prismatic bar if it is to have the same maximum permissible load as does the stepped bar?

Transcribed Image Text:

Pi P2 di do