- #1

noboost4you

- 61

- 0

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.

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

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

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

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

Last edited by a moderator: