Composite Metal Deck Floor - MOE 1

[XR250]

I'm trying to hand verify the deflection of a new residential composite floor system design.
I designed it with one of Vulcraft design tools but the output seems sketchy. (5" total thickness concrete on 1 1/2" x 20 ga, L/900, 14 ft. span. - shored (obviously))
They provide the "Id". What modulus of elasticity should I be using in conjunction with this?

Thanks

 

[ProgrammingPE]

You should be using the modulus of elasticity of the concrete steel (Revised per comments below).

Ec = wc^1.5*33*√f'c (ACI 318-14, Equation 19.2.2.1.a).

The value for Id also depends on Ec, so you'll want to make sure you're using the same value that they did.

SDI C-2017 (Calculation of Id found on page 41-43)

Structural Engineering Software:

http://www.structuralcentral.com

Structural Engineering Videos:

http://www.youtube.com/channel/UCOj2mXXf3ZbZtgxTc6BtkGg

 

[XR250]

Thanks PPE

 

[XR250]

Can someone double check this for me for 20ga? I ran it at L/900 but get 1.75" of live load deflection (L/95) when computed by hand (E = 3.12 E6, Id = 8.18) Am I doing something wrong or does the Vulcraft tool have an issue?

Thanks
[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1626981481/tips/1.5_o4bjjf.pdf[/url]

 

[XR250]

Talked to Vulcraft. Apparently, need to be using E steel and not E concrete. That explains it.

 

[phamENG]

The calculation referenced by PPE mentions a conversion to steel:

 

[XR250]

Got it - thanks!