Engr Help

Analysis of Trusses (continued)

Recommended strategy: Assume each truss member is in tension when

constructing your free body diagram. Then when the resulting force from the

equilibrium equations comes out negative, that means that the truss element is

actually in compression.

Also take advantage by identifying “zero force” truss members.

In the figure below truss members AB, BC, and BD are connected by a

smooth pin at B.

Note: The force in member BD must be zero for any angle θ other than

zero since equilibrium in the y-direction must be satisfied.

i.e. ∑ F_y = 0