Slenderness - In-plane moment
Slenderness - In-plane moment
(OP)
Elders,
I have a question regarding how the T/C due to a huge in-plane moment on a tall planar wall is accounted for.
For example if I had a 30' long wall with 20' story heights laterally supporting a 20 story building, what kind of localized compression behavior would be present towards the outer core of the wall? Would the high compressive force induce some sort of local buckling? I am not able to visualize it completely, and the only thing I can visualize is a warping of this 20' high wall (akin to a pseudo S shape).
Any ideas?
I have a question regarding how the T/C due to a huge in-plane moment on a tall planar wall is accounted for.
For example if I had a 30' long wall with 20' story heights laterally supporting a 20 story building, what kind of localized compression behavior would be present towards the outer core of the wall? Would the high compressive force induce some sort of local buckling? I am not able to visualize it completely, and the only thing I can visualize is a warping of this 20' high wall (akin to a pseudo S shape).
Any ideas?






RE: Slenderness - In-plane moment
You solve for not only the tension in the steel, but the "extreme fiber compressive stress" in the concrete at the end of the wall. This "stress" is normally expressed in terms of kips-per-foot. You can average this compressive stress over whatever wall segment increments you choose based on judgement, and design each segment of wall as a column.
One further complication is WHERE do you analyze the "column" section, since axial stress varies over the story height... do you analyze at mid-height of each story/unbraced length to get an "average" axial load?... at the top & bottom and "average" that way? Do you base the assumed width of column on the shape of the stress blocks top & bottom? Since the axial load varies over the height of the "column", do you assume a reduced K-factor for minor axis/out-of-plane slenderness considerations? All of this involves some engineering judgement.
I know this is not a totally thorough explaination, but it's a direction.