I've been having difficulty with this problem for the past 5 hours. I am understanding some part, but I can't get the final answer.(adsbygoogle = window.adsbygoogle || []).push({});

http://img223.imageshack.us/img223/1103/1015zz1.th.jpg [Broken]

This is what I got so far:

EFx = Ra + Rb - P = 0

Ra + Rb = P

Sab = Sac + Scb = [(-Ra)(a)/AE] + [(Rb)(b)/AE] = 0

-Ra(a) + Rb(b) = 0

-Ra(a) + (P - Ra)b = 0

Ra = (b/a+b)*P

Rb = (a/a+b)*P

Ra = (8in/18in)*100kips = 44.44 kips

Rb = (10in/18in)*100kips = 55.56 kips

I found the reactions but I cannot find the stress of each segment. The fact that the problem isn't giving me the modulus of elasticity is throwing me off.

I know stress = P/A where P = force and A = cross-sectional area

I figured then stress for segment AC = 44.44kips/6in^2 but it doesn't equal the answer in the back of the book. I also figured that would be the same for segment CB but it's not.

Please help because I feel like I've done everything I can to this problem

Thanks

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Statically Indeterminate Stepped Bar Problem

**Physics Forums | Science Articles, Homework Help, Discussion**