How Do You Calculate Torque Around Point D in a Lever Setup?

[BatsDude]

Hi guys,

It's been a while since I've done much resolving forces stuff, and I'm struggling to make sure what I'm doing is right. I have a setup like below, and I want to find the torque around point D due to the force acting at point A.

I've had a couple attempts but I feel like I'm just guessing and I'm not sure if I'm correct.
I know the force acting at A produces a torque at the fulcrum of F*(alpha/2)*sin(theta) but is this the force that's also seen in the BC member? From what I understand, if I can find the force acting in the BC member, it should be easy to find the torque around point D.

Any help would be good! Thanks

 

[scottdave]

This is a question about the problem: is AB fixed on the fulcrum (just pivot), or can it also slide up and down in relation to the fulcrum? It has been a little while for me, as well.

 

[BatsDude]

Hi,

It's fixed on the pivot. Apologies for the lack of detail!

 

[BatsDude]

For anyone playing along, I've got a solution.
The force in BC is the reaction force from F in a simple lever setup.
Then this is the force acting at the top of member CD which creates the torque.