I might have a brain cramp here but I'm trying to sort this out:
Typically when we create Axial-Bending moment (P-M) interaction diagram we use "material limits" and don't really consider any sort of buckling whether it be local buckling or lateral torsional buckling. For example:
Lets say you were creating a P-M diagram for a concrete or masonry column/pier whatever. You would iterate your N.A. location and sum the moments based on the compressive strength of the concrete and yield strength of the steel (what I'm calling material limits). However you would limit your compressive capacity to the maximum allowable axial load for the entire section based on Ag (ACI eqn 10-1 or around there). However this does not consider any buckling effects, which I suppose would need to be addressed by finding the exact capacity of the section based on the applied loads and then check via moment magnification or something along these lines?
However where it gets confusing for me is when looking at an interaction diagram for shear walls. Again you iterate the N.A. limiting your capacity to the material section but there is no local buckling check. I suppose you could compare just the axial load on the wall to the allowable (as a separate check), but what if you have a very low axial load and a very high bending moment with a very tall thin wall, is there a check to make sure you 'end piers' will not buckle? Is there some way to incorporate this into a P-M diagram? Or are they typical separate checks - i.e. for a shear wall you check the P-M diagram then you check axial only your wall to ensure it has required strength for axial only?
Hopefully this is clear? If not I can post a sketch. Thanks!
EIT
Typically when we create Axial-Bending moment (P-M) interaction diagram we use "material limits" and don't really consider any sort of buckling whether it be local buckling or lateral torsional buckling. For example:
Lets say you were creating a P-M diagram for a concrete or masonry column/pier whatever. You would iterate your N.A. location and sum the moments based on the compressive strength of the concrete and yield strength of the steel (what I'm calling material limits). However you would limit your compressive capacity to the maximum allowable axial load for the entire section based on Ag (ACI eqn 10-1 or around there). However this does not consider any buckling effects, which I suppose would need to be addressed by finding the exact capacity of the section based on the applied loads and then check via moment magnification or something along these lines?
However where it gets confusing for me is when looking at an interaction diagram for shear walls. Again you iterate the N.A. limiting your capacity to the material section but there is no local buckling check. I suppose you could compare just the axial load on the wall to the allowable (as a separate check), but what if you have a very low axial load and a very high bending moment with a very tall thin wall, is there a check to make sure you 'end piers' will not buckle? Is there some way to incorporate this into a P-M diagram? Or are they typical separate checks - i.e. for a shear wall you check the P-M diagram then you check axial only your wall to ensure it has required strength for axial only?
Hopefully this is clear? If not I can post a sketch. Thanks!
EIT
