Axial Influence Lines

[fasboater]

I am prepairing for the SE in April and struggling with axial influence lines. Question number four of the 246 Solved Structural engineering Problems by Dale Buckner essentially gives a steel bridge truss. He wants axial influence lines constructed for members in this truss. How do you draw an influence line for axial loading?

The first part of the problem yields a section that has a reaction of 2k in compression.

Thanks

 

[graybeach]

You do this the same way as any other influence line. Plot the axial force in a particular member as the load moves across the structure. Your y axis will be the axial force and your x axis is the length along which the load moves.