Calculating Reactions for Three Pinned Beams - Structural Engineering Homework

[sukibelle]

Homework Statement

http://tinypic.com/r/2wbxm2s/7
This is a series of beams pinned together at A, B, C
Find reactions at a b c

Homework Equations

Sum of moments at B has to = 0, sum of Fx = 0, sum of Fy = 0

The Attempt at a Solution

Sum of moments about A, anti clockwise +ve
2(-16) + 8Cy -4Cx = 0

considering section BC
sum of momeents about B
4*-25 + 4Cy -8Cx= 0

solving ffor Cx = 61.33


I've been staring at this question all day, it has literally stopped making any sense.

 

[sukibelle]

http://tinypic.com/r/2wbxm2s/7 if the image doesn't come up eventually

 

[PhanthomJay]

Homework Statement

http://tinypic.com/r/2wbxm2s/7
This is a series of beams pinned together at A, B, C
Find reactions at a b c

Homework Equations

Sum of moments at B has to = 0, sum of Fx = 0, sum of Fy = 0

The Attempt at a Solution

Sum of moments about A, anti clockwise +ve
2(-16) + 8Cy -4Cx = 0

considering section BC
sum of momeents about B
4*-25 + 4Cy -8Cx= 0

These equations are both correct

solving ffor Cx = 61.33

You didn't solve the 2 equations correctly.

I've been staring at this question all day, it has literally stopped making any sense.

Redo the algebra. Cx will come out negative , meaning you assumed the wrong direction for Cx. After finding Cy from these equations, use the other relevant equilibrium equations to solve for the support reactions Ax and Ay, and the internal forces Bx and By at B.