Just found this forum--hope there isn't a max post limit haha. I have been a bit stumped on this, but when doing problems about deflection and axial loadings, I am confused when to use which equation. I think I know that axial member need to be 2 force members, loaded only at the ends, and this means you can use δ=FL/AE. However, I had a problem with two axial bars connected at two ends and it was made clear that I could not use the above equation, but had to use σ=δL/E. I guess my main question is where do I use which, what exactly is axial loading, and what is statically indeterminate mean does this make it unusable?? Thanks!