Engineering Help with a statics problem finding free members and two force members

[Zulliz]

Homework Statement

So ive gotten the problem i have to solve, and for some reason this 2-member forces and dividing the frame into members simply does not click with my brain, it should be so simple, yet i cannot get it right.

Ive attatched a picture of the problem as well as my intended equation for moment around point A, can you guys tell me if im on the right track?

And even better can you help me find the forces applied in A, B, C and D? Im completely stuck, for some reason my brain cannot comprehend this 2 force member stuff and i dont know why…

Relevant Equations

SUMof moments in clockwise direction around A = 0

Heres my first attempt at finding the forces at D:

https://i.sstatic.net/CRv5Ikrk.png

 

[Lnewqban]

Welcome, @Zulliz !

Your first attempt seems to be correct, but representing the vector F at D would be better.

The horizontal 2F keeps pressure on point C, and the 2-member acts like one solid part.

 

[Zulliz]

Welcome, @Zulliz !

Your first attempt seems to be correct, but representing the vector F at D would be better.

The horizontal 2F keeps pressure on point C, and the 2-member acts like one solid part.

But how would i go about it then? Can you elaborate? As I tried to explain my brain is simply shutting down on the two-force members and im having such a hard time understanding how to do them unfortunately.

Would i do sum of moments around B to find the force F pressing up at point C using the 2F x a - 2a x C?

 

[Lnewqban]

But how would i go about it then? Can you elaborate? As I tried to explain my brain is simply shutting down on the two-force members and im having such a hard time understanding how to do them unfortunately.

If the problem requires you to analyze each part separately, do a free body diagram of each.
Represent the external given forces first.
Then, represent all the reactions (forces and torques) that the part would need to have acting on it in order to remain in static equilibrium (not moving).

Would i do sum of moments around B to find the force F pressing up at point C using the 2F x a - 2a x C?

You will need to calculate the magnitude of the force acting at D first, since that moment matters.

 

[Zulliz]

If the problem requires you to analyze each part separately, do a free body diagram of each.
Represent the external given forces first.
Then, represent all the reactions (forces and torques) that the part would need to have acting on it in order to remain in static equilibrium (not moving).


You will need to calculate the magnitude of the force acting at D first, since that moment matters.

So something like this?