I am trying to analyze a building with CMU and CFMF shear walls. The diaphragm is a metal deck with 3" of concrete supported by CFMF floor trusses. I understand that RAM SS does not design CMU and CFMF shear walls but is there a way I could at least get the design forces? How does the software determine the relative stiffness of the walls if I assume a rigid diaphragm?
You can model these using Concrete or Other material walls, typically lateral walls. You need to define an accurate E value, thickness (and unit weight). Then you can get forces from the Ram Frame analysis including wall group forces or reactions if needed. In a rigid diaphragm the connected walls have to move together in plan (deformation compatibility). The walls are meshed finite element plates connected to the diaphragm along the length.
Thank you, Seth. Let's assume I model my masonry walls as lateral concrete walls in RAM SS and assign them an appropriate weight and elastic modulus. I am interpreting that RAM would distribute the diaphragm shear to these walls based on their rigidity. But the masonry code has limitations on the effective width of wall flange that can be considered. For example: "0.75 multiplied by the floor-to-floor wall height for reinforced masonry when the flange is in flexural tension".
Is there a good way to impose this when determining how much shear goes in the walls parallel to the wind direction and axial force in the walls perpendicular to wind?