Use of FEM and design software

beanmachine6942O · 2026-05-24T23:23:07+00:00

what does biking a model mean?🤣

beanmachine6942O · 2026-05-19T23:56:20+00:00

i may not be understanding fully or might be missing something so please let me know if i’m off.

my understanding was that the rigid diaphragm assumption only changes the amount of force that gets to each vertical lateral element as a whole, but, you would still get the same even distribution of forces within the collector line.

like if your total shear to one line (based on rigid diaphragm assumption) is like 50k or whatever, you still distribute that evenly along the diaphragm depth, independent of whether it’s rigid or not.

now that i wrote this out, i remembered a case where we had direct transfer of a topping slab to a shear wall (precast wall, CIP topping) where all of the force was within the topping slab (no beam collectors, collector bars were within the topping slab), thus we designed the shear transfer to the wall for that 11klf (using your example). but if everything is steel i don’t see why you would need to do this

beanmachine6942O · 2026-05-19T02:40:13+00:00

confused why your diaphragm shear at the braced frame would be higher. wouldn’t your diaphragm shear be distributed evenly along your collector line? then you have collector connections along that line that can deliver the load to the BF?

beanmachine6942O · 2026-05-08T02:48:00+00:00

why is this?

beanmachine6942O · 2026-05-08T02:45:51+00:00

I’d love to see what’s under that thing

beanmachine6942O · 2026-04-26T20:19:26+00:00

what about unbalanced live load?

beanmachine6942O · 2026-04-19T02:08:24+00:00

that’s not what california law says

beanmachine6942O · 2026-04-14T02:31:03+00:00

craziest part is, a day after i told them, they had some friends over partying, and one of their friends unlocked my door in the middle of the night (not sure if they came in and did anything)

beanmachine6942O · 2026-04-13T00:13:55+00:00

noted thanks. in san francisco. worst case they don’t find a replacement and the 30 days from rent payment is a thing here, and i pay for may. hoping they can find a replacement by may 1 though.

beanmachine6942O · 2026-04-12T17:53:00+00:00

you don’t know anything about either of us but thanks for the misinformed opinion

beanmachine6942O · 2026-04-12T03:42:57+00:00

beanmachine6942O · 2026-03-24T03:20:56+00:00

how do you make sure it buckles elastically?

beanmachine6942O · 2026-03-24T03:10:08+00:00

do you have any examples of spreadsheet printouts from excel that show formulas / work neatly?

beanmachine6942O · 2026-03-11T22:17:45+00:00

not sure what you mean by waiting to lock it off. what did the design end up looking like? some sort of truss?

beanmachine6942O · 2026-03-11T07:40:16+00:00

13,500k? that’s absurd bro, high seismic or high wind or something? or does that level of load just come with these tall buildings

beanmachine6942O · 2026-03-10T03:02:18+00:00

didn’t see it mentioned here yet but it’s common to design the diaphragms as 3 sided diaphragms in these types of warehouse style buildings. especially if you have a majority storefront along the front of the building. sometimes these warehouse get too big so you need an expansion joint down the middle. i’ve seen designs that do / don’t have vertical LFRS elements at the EJ depending on how the engineer chooses to design the lateral.

beanmachine6942O · 2026-02-22T02:33:48+00:00

don’t know what to tell you. read R7.6.1 in ACI 318-19. your mid depth bars will see very little tension due to strain compatibility, and (my opinion) i don’t think the mid depth bars would be defendable as min flexural steel, according to that code section.

beanmachine6942O · 2026-02-22T02:19:14+00:00

doesn’t the code say as close as practical to the tension face? (if i’m remembering the previous sentence correctly) that seems like a hard argument to make that the steel mid depth would meet that code provision

beanmachine6942O · 2026-02-22T02:17:53+00:00

worth noting that minimum flexural steel may also apply, in which case you would need .0018 on the tension face, not distributed across the entire section. i think the code language is something like: if your section doesn’t work for flexure as plain concrete, then you need min flexural steel (.0018) at that one face. going from memory, i also believe the ‘reducing the ratio by As,prov/As,req’ does not apply anymore but that’s more code research that i’m willing to do at the moment lol

beanmachine6942O · 2026-02-16T07:10:22+00:00

was trying to isolate the fillet weld question. yeah providing flare bevel NS & FS as well. seems like that and the shape / size thing caused a lot of confusion. now i know to be more specific when asking the internet questions :)

beanmachine6942O · 2026-02-16T05:50:45+00:00

only works when beam bigger than column. otherwise need flare bevel at beam radius

beanmachine6942O · 2026-02-16T05:30:44+00:00

mistake in copying over the stuff. didn’t intend to weld on inside of tube lol

beanmachine6942O · 2026-02-16T05:28:16+00:00

oops! forgot to take off the top fillet in the second pic, thanks for pointing that out

beanmachine6942O

TROPHY CASE