I am a bit confused on how ram handles parapet exposure so I wanted to be sure I was interpreting correctly.
In the user manual, it says that "parapets are only considered when the building steps, that is, the extent of the level above perpendicular to the direction of the applied wind force is less than the extent of a given level."
Consider a building that is two stories, both stories are the same height, but the footprint of the higher story is 1/4 of the lower story. See below in Figure A, red indicates the lower story, and blue indicates the higher story. Also consider that there is a parapet all the way around the lower story who's height is equal to the upper story. Based on the wording of the manual, I would assume that wind on a parapet is generated like in figures B.1 and C.1, where the highlight indicates the length of parapet that the program is considering. However, figures B.2 and C.2 indicate how wind on parapet should be realistically generated.
Is ram generating wind on parapet like in figures B.1 and C.1? Or is it generating wind on parapet like figures B.2 and C.2?
If ram is generating wind on parapet like in figures B.1 and C.1, is there any easy way to ensure that wind load is eccentrically applied to the lower story diaphragm beyond user defined story forces or nodal forces?
The program uses a method like B1 and C2. The exposure boundaries report can be used to confirm this. There is no easy way to have a parapet included and also have a higher story included in the exposure across the same width. User defined story forces are the alternative for most wind conditions beyond the program assumptions.
Answer Verified By: Andrew DeWilde
I didn't realize that the exposure boundaries report existed, thanks for the help! Guess I should've read through the manual better...