Does Bentley have recommendations for modeling wood shear wall stiffness in RAM SS? I am working on a concrete podium project with 4 stories of wood framing above the top concrete level. I would like to do a 2 stage lateral analysis in RAM SS to determine the lateral loads applied on the concrete podium structure. The design of the wood framing will all be done by hand but I wanted to know if there are recommendations for wall properties for wood shear walls in modeler to adequately model the relative stiffness of the wood structure.
The tricky part with wood walls is that the stiffness is not simply a matter of the shape (due to hold downs, nailing patterns etc.). Two walls built the same way but of different lengths have dramatically different stiffness, more so than you get naturally from finite element analysis, so modifications to the wall E value are required for various wall lengths. I know people who have back-calculated the effective stiffness E' for walls based on Ram Frame deflections under unit lateral loads, but it's a pain. In the end I'm not sure how much difference it really makes in the design of a podium using 2 stage analysis.
There is some more on this topic here: https://communities.bentley.com/products/ram-staad/f/ram-staad-forum/127685/overturning-moments-on-shear-walls and in our Walls FAQ.
Answer Verified By: Nathan Foust