Identify the zero force members for the truss shown in the figure.

Explanation:

Rule for zero member force:

• At a joint, if three members are meeting, two members are collinear (same line), then force in the third member is always zero (if there is no external load at that joint) as shown in figure (1)
• At a joint, if two non-collinear members are meeting with no external load at that joint then forces in both members will be zero as shown in figure (2).

Calculation:

As per Rule 1

Zero force members = GH, FG, DE and CD

As per Rule 2

Zero force members = BF and EI