Question: A shaft is machined of cold drawn AISI 1020 steel. It is rotated at 500 rpm. The shaft is 100 mm long between supports. A 4.5 kN force is applied continuously in the middle of the shaft for 10 hours. What is the diameter that I need if a safety factor of 1.3 is used?
Take as load only the bending moment caused by the force into account and use the SN diagram below.
Given: Shaft bending stress, ? = M/Z
Z = section modulus of the bar = ?D3 /32 the SN diagram is in PDF file, as well as the complete question
