Here's the question you clicked on:
arcticf0x
Analyze this structure- Truss
My approach- Clearly using the method of sections. But there comes a point where taking moments is confusing.
If you're only given that one force, what I think you're going to find is a set of simultaneous equations in the force variables, which you'll need to solve. So go through and patiently set it up, setting all the moments about joints equal to zero, as well as sums of forces in x and y directions equal to zero, and you should have enough equations to solve for the forces due to the individual beams.
"If you're only given that one force", by which I mean the value of that one force.
Nah, that force is not even useful when i cut it around DH, DC and EC and use the left part. Anyways i am working on it, will post the exact point where i am stuck.
That force is useful, because by symmetry that must also be the force at one other point...namely, at E
Hmm, yeah right, how about i cut and analyze the right part.
No. Just translate that force over to E and stay where you are. It'll get confusing if you start looking at other beams.
Or at least that's what I'd do.
Ok i got it, you need to extend one arm out to take the moment from that external point. The logic being, this kill 2 unknowns of the three! Thanks for posting here JamesJ!
Happy to help. It's also fun to see this problem, as I haven't see it for this sort of thing for a while.
Haha ok, i have loads of these right now. Just 1 more day to the exam!