Frame Works Trusses Homework: Determine Forces in Trusses

[Colin Luu]

Homework Statement

I need to verify a couple of unknown forces in a truss, attached image (all individual trusses are 300mm in length)

Homework Equations

Determine the forces in trusses shown.

The Attempt at a Solution

This is a lab and I've used a telescopic gauge with a calibration chart to obtain a rough value of what the forces should be, (missed too many classes on Framworks damnit!)
From Left to Right Box, Left 100N Tension, Right 187.5N Compression RL is 163.5 N Rr is 130.8N
Even is i have a parallel worked example it would be enough.

 

[Colin Luu]

okay I've done it with method of sections and resulted from left box to right 98.1N and 65.4N which is way off the lab value 187N for the right box can anyone verify these results?

 

[mathmate]

We do not see the diagram yet while it is pending approval.
Could you supply your calculations how you obtained 98.1 and 65.4 N?
Have you taken into account the dead weight of the truss?
If the truss has only two pinned supports, you do not need to calculate by sections to get the reactions. Simply taking moments will do.

 

[Colin Luu]

Sorry i forgot to mention this is neglecting frame weight, I'll scan the working out tonight and upload.