Astepped rotation shaft with diameters of 40 and 30 mm and a notch root radius at the step of 2 mm is to be subjected to a fully reversed comstant amplitude bending moment m. the desired life of the component is 90,000 cycles. the shaft is made of 2024-t351 aluminum. kt = 1.8. kf = 1.65.

using the notch strain analysis method, estimate the allowable bending moment by using a) neuber rule and b) glinka's rule (strain energy density).