Hello,
What should i do in order to simply design my building for gravity loads.I am using the plate elements in my structure.How staad works out the loads from slab to beams?
Your question is very brief and general. It is not posible to furnish the full particulars. Only few lines I can spell out is that you will have to assign thickness and material property to plate. I believe you are aware of creating plates. Apply pressure as per plate load item. But before applying the load, plate has to be meshed so that plate load is transferred to the beam through the common nodes between plate and beam. I will suggest you to take the help of Technial Reference Manual and Staad Graphical to clear your doubts. One more thing that I feel it is better to simulate plate with the floor load and Master slave .If you are not applying lateral loads Master slave also may be omitted. Meshing of plate leads to poor management with the model.
sureshprsharma
yes i know the said thing but in actual practice we have different conditions for plate such as simply supported, fixed etc. then in space frame with the model say 3*3 bay both sides and height of building say 20 meter then in that case if i am using the plate element and applying the pressure then how to assigned the different conditions of plate. i think i have to separately design it or what ? The building may be of composite type
If by FIXED, you are referring to a monolithic connection between the beam and slab, here is a way to simulate that. Model the slab using a mesh of plates. Subdivide the beam into several segments. Ensure that those segments and elements are connected to each other at all those nodes which lie along the boundary between the beam and slab. The default connection between a beam segment and a plate element is treated by STAAD as one through which all three forces (FX, FY and FZ) and all 3 moments (MX, MY and MZ) are transmitted to each other which is what you would expect from a monolithic connection. Hence, other than the properties, material data and loads, there is nothing extra that you need to assign.
If the connection is not monolithic, meaning, if the slab is simply resting on the beam and does not transfer any moments to the beam, you could model the beam and slab at the elevations of their respective shear centers (or centerlines if that's what you prefer). This too requires that the slab is meshed and the beam is segmented. Then, use the master-slave feature to link the beam segment nodes to the element nodes along their boundary. The link will be just for FX, FY and FZ. By leaving out MX, MY and MZ, there will be no moment transfer. Without this additional step, the slab and beam would be identified as being physically separate entities with no connection, and no load transfer would be possible.
For designing the slab, the quickest way is to use the link between STAAD.Pro and RAM Concept. In the STAAD.Pro GUI's modeling mode, look for the tab called Advanced Slab Design. After the analysis, click on this page to launch the RAM Concept program if you have a license for it. If you don't have RAM Concept, you'll have to take the results from all those elements and design the slab manually, which can be quite tedious.