Truss Analysis: Solving for Zero Force Members using Method of Joints

[VooDoo]

Hi Guys,

I am having trouble determining the zero force members in the truss below. I am planing to use the method of joints to solve for the forces in the beams. So if I knew the zero force members it would be easy.

 

[dav2008]

I don't believe there are any zero-force members in that truss.

Do you know the criteria to look for when determining zero force members? Go through the truss and see if any of the joints meet the criteria.

 

[VooDoo]

I don't believe there are any zero-force members in that truss.

Do you know the criteria to look for when determining zero force members? Go through the truss and see if any of the joints meet the criteria.

That is what I thought as well. But then if you look at it this way:

The horizontal component of the force in member BI is conteracted by the horizontal force BC. Therefore what is the force HI doing?

 

[haynewp]

There are no zero force members for this load arrangement. JD would be a zero force member if there was not a load applied at D.

There has to be equilibrium at each end of member BI. HI is balancing joint I and BC is working to balance joint B