Cantilever steel shaft is loaded by concentrated couples.
Given: l1=2l; l2=1,1l; l3=1,5l; M1=-1,6M; M2=-1,1M; M3=1,3M. Parameter of length l=20cm; parameter of load М=373Nm. The shaft is made of steel with yielding shear stress τY=170MPa; factor of safety n=1,4.
Find: the diameter (in mm) of cross section from strength calculation d = ?