Leaderboard

See the following links for clarification: 1. Load pattern 2. Load case 3. Load combination Regards.

Why NOT? The ONLY limit on your thoughts is the one you put on yourself.

F11 is axial force along local 1-1 axis. Negative is compression. Positive is tension. Gravity loads cause bending moment as you know it. Moment is nothing but a couple with opposite forces. These are F11. Multiply this with depth of beam (which is equal to distance between couple forces), you will get the moment at mid-span for example. You can verify by hand. Shear is not F11..Shear is F12. Remember the basic cube with directions marked on it in strength of material course?

It could be. All depends upon relative stiffness. Their are buildings where column configuration changes after X number of stories. The floor at that specific level is very very thick to allow for new columns arrangements (and satisfy other limit states requirements) but this happens all the time in high rises in Dubai.

Here, My fav on diaphargms Diaphragm behavior and idealizations Rigid diaphragms, symmetry, and relative stiffness All frames equal stiffness Symmetrically arranged & equal stiffness means equal resistance Under the rigid diaphragm idealization, the symmetrically arranged identical frames experience the same deflection, and provide equal resistance. Center frame is twice as stiff All frames equal stiffness Third frame is twice as stiff All frames equal stiffness Third frame is twice as stiff Third frame is twice as stiff Concrete slab Ideal rigid diaphragm Concrete slab

Diaphragms connect all individual members into a seismic force resisting system. If you have concrete floors, it is imperative that your floor will do the above mentioned job plus distribute the seismic load to all the connecting members too. Diaphragms can be rigid or flexible depending upon their stiffness. For practise in Pakistan, if your flooring is type conc slab > 5" consider your diaphragm to be rigid. A rigid diaphragm distributes forces to connecting members based on connecting members stiffness, where as a flexible diaphragm distributes loading based on tributary areas of supporting members to diaphragm. Take diaphragm as a frame that connects all members, and makes them act together.