design a tension member w/ cross section.... 1. The problem statement, all variables and given/known data You are to design a tension member (square rod) with a cross section to carry a mass of 575 000 kg with a safety factor of 2 against yield and a safety factor of 3 against static fracture (overload). a) What is the design stree that you will use for the application? Why? b) What are the appropriate bar dimensions for use? 2. Relevant equations FS = UTS / R [sigma] = F / Ao Ao = L * w 3. The attempt at a solution FS = 1279MPa / 3 = 426.33333... MPa ~ 426 MPa that's the design stress considering static fracture FS = 862 / 2 = 431 MPa that's the design stress consider yield stress/strength So, I'm considering using a design stress that is the average of these two values, which would be: 429 MPa I'm just confused, because we haven't done anything like this in class. Now for part b) [sigma] = F / l*w F = 575 * 103(kg) * 9.81(m/s2) F = 5.641 MN (mega Newtons) 429 = 5.641 MN / Ao[/SUP] Ao = 13148.6014 MM (mega meters? I'm not sure about the units on this one) l = w = 6574 MM Please help and thank you.