These videos are great! Thank you. Do you happen to have pdfs from these 3 lecture videos? I'd love to have this by my side at work for references.
@bagusbudi3018
2 жыл бұрын
Great video, gaining more understanding. what is the main goal of designing the diaphragm, is it to design the reinforcement? or to check the load transferred to the vertical system? Tks
@SudheendraHerkal736
Жыл бұрын
Hi, why doesn't out of plane wall transfer load to lateral load resisting system directly?
@dougschmucker8212
Жыл бұрын
Think of it this way ... walls only have significant strength and stiffness in their plane. Out of plane, they typically behave as a simply supported beam (a 1-ft wide strip that runs up and down). They transfer the forces perpendicular to their surface (such as wind and seismic effects) to the "top" and "bottom" of that strip. Sometimes, the engineer designs the wall for the strip to be horizontal rather than vertical. Either way, the wall transfer those load effects over to perimeter elements (could be a column, beam, or wall that is perpendicular to the wall of interest; could be a floor or roof system). The reason is that in-plane behavior is very stiff involving shear and normal strains that are very stiff ... think in terms of EA/L like in an axial stiffness situation as opposed to EI/L^2 or L^3 for bending situations. Out of plane wall behavior is like bending of a beam. It is more complex than just EI/L (the latter being beam bending behavior but the wall is really structural plate behavior). If that is more theory than you like, consider it this way. Glue a bunch of long sticks together and stand the whole thing up like a wall. Clamp ahold of the "Wall" at its base. Try to push it in-plane. Compare that to what happens when you push it out of plane. In the extreme, think of the wall as a sheet of paper. That sheet of paper has almost not out of plane stiffness.
@SudheendraHerkal736
Жыл бұрын
@@dougschmucker8212Hey Doug, that makes sense but my question was along the lines of why is it always assumed as though the out of plane walls are one way slabs transferring loads to diaphragm and footings, and not as two way slabs with loads being transferred to the in plane walls as well?
@dougschmucker8212
Жыл бұрын
@@SudheendraHerkal736 Two basic reasons: engineering design is about what is good enough as opposed to what theoretically might be, and what is simplest and easiest to do that gets the job done. Regular walls are typically designed and constructed as one-way systems and most often they behave that way as well. Maybe even more importantly: too time consuming to work through and verify the two-way slab design process even if automated in a computer ... Note that most of the computer solutions are nothing more than a way to code up the hand based solutions. It is rarely if ever a true FEM solid modeling of a three dimensional slab. We wouldn't even know what to do with those stress calc's because of the complex nature of reinforcement and matrix interactions. Instead, we always end up with approximate methods whether by hand or by computer tools. We can be more efficient with our time and end up in a safe place using one-way methods. Then, if we need to refine what we are doing, then we can do something more precise. And, finally, if you start adding openings, then you are going to end up with something way different than just a "two-way" slab wherein you add so much reinforcement that you might as well have trust treated it as a series of one way strips. Obviously, people have found all kinds of different ways to do things, but these are many of the reasons why we start with a very simplistic model and only add complexity as it is genuinely needed.
@SudheendraHerkal736
Жыл бұрын
@@dougschmucker8212 Hey Doug, that makes sense! Thank you!
@yusrilabdurrahman1936
4 жыл бұрын
Thanks man
@dougschmucker8212
5 жыл бұрын
You are welcome
@SuperMoa88
5 жыл бұрын
Very informative. A question, if i assume my deck(slab) to be a rigid diaphragm my steel frame to be hinged and have an inner shear wall, will the columns take any lateral loads. Or will it be transferred directly to concrete core?. (Steel frame with concrete core scenario) Thanks
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