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Thanks for the replies everyone.

I wrote some software in Python that basically analyzes any beam that the user enters and determines support reactions/deflections. I accomplish this using stiffness matrices. However now I want to be able to draw the shear, moment, and deflection diagrams for the same beam. I could probably...

JAE, thats fair. I just have had trouble getting drift to check on multi-story moment frames with brittle cladding in the past when using 50-year interval. If you have a braced frame or shear walls I doubt its an issue.

I meant to say 50-year seems like overkill, typed 5-year instead lol. But interesting. That's above and beyond.

What do you typically use instead? IMHO, using true 50-year wind for serviceability seems like overkill.

Can anyone explain to a young engineer WHY dowels are used at control/contraction joints? In my experience, we, like MotorCity, have only used them at construction or cold joints. All of our control joints are sawn to 1/4 of the slab thickness, with the reinforcing continuous through it (most...

Assuming a 3-span condition, I think you can accomplish 700psf + DL with 8" slab over 3" NC decking. WWF likely wont suffice though. You'll probably need (2) layers of #4 bars @ 12". And you'll have some very heavy steel below depending on the spans, but thats where I'd start anyways.

...Metal decking alone or with concrete topping? Composite action or non composite?

Your note looks like a good compromise, provided your precast supplier reads it. We typically design elevated slabs on metal deck over bar joints. Design load is 125psf majority of the time. Reinforcing is welded wire fabric. What we have noticed, is given these conditions, if you run thru the...

You may get results closer to what you expect if you apply a uniformly distributed axial load to the collector elements instead of a single point load at one or either end of the frame. This would more correctly model how a diaphragm is distributing load anyways.

This is a fair argument, and I agree. If this is the only answer I receive, I accept it just fine. I just know that there are a lot of people here who understand structural analysis much more so than myself. I did some searching on this forum for this question before posting, and some...

For a rigid diaphragm, I would agree that a typical floor has mostly the same size joists/beams, so equal stiffness and the tributary area method holds water. I'm curious the argument for when girders come into play or weird framing such as if you have a lot of floor openings. For a flexible...

Hi all, When modeling uniformly applied gravity loads to a structure, engineers often distribute them based upon tributary area. However, I have been thinking, whats the theory behind this? Wouldn't a steel deck behave as a flexural member and distribute load to supporting members via beam...

I'm not sure about ASCE 7-16, but in 7-10 I usually design for drift by using (0.7)(0.6)=0.42 for my wind load factor. The 0.7 is recommended per AISC design guide 3 for a 10-year recurrence interval and the 0.6 is because I design using ASD. Obviously if you design using ultimate loads you'd...

Would this approach also work for checking a lifting beam for LTB?

I'm sorry, I don't follow. How would battening together the flange tips not provide LTB restraint in this case? It may be old school, but I've always been told that only 2% of the compression flange force is required to classify as lateral bracing. You must've had some incredible loads to not be...

Could you not just reduce the capacity of your vertical bars by the ratio of (development provided/full development)? Why does ACI require the verticals to be fully developed for shear transfer here? Although you may not get much out of them considering your pier is only 6" in this case.

Thank you for your response. You're correct, the crane column likely does not need to be fixed. Regarding the lacing design, I do remember reading in DG7 that fabricators prefer W-shapes to the lacing angles. This ship has not sailed yet so I have time to explore alternatives. Do you have any...

Please see the attached for a screenshot of my RISA model.http://files.engineering.com/getfile.aspx?folder=dda28a04-46ba-4b1d-97e7-a78b41af82ad&file=laced_columns.PNG

Hi everyone. I am in the process of designing a laced column system for a new bldg. The new bldg houses a magnet crane, and we are to follow TR13 requirements for the design of its support. I have available to me AISC DG7, AISE TR13, and ASCE "Structural Design of Industrial Buildings", all of...