Analyzing a slab as crossed beams
Analyzing a slab as crossed beams
(OP)
Hi all
I am wondering if it is OK to model a flat slab as a number of beams in two directions. How the forces differ in both cased.
The reasons for the question are:
1-I don't have a FE program to analyze flat slabs and,
2-Both the direct method and the equivalent frame method for analyzing slabs use the bending theory.
I am wondering if it is OK to model a flat slab as a number of beams in two directions. How the forces differ in both cased.
The reasons for the question are:
1-I don't have a FE program to analyze flat slabs and,
2-Both the direct method and the equivalent frame method for analyzing slabs use the bending theory.





RE: Analyzing a slab as crossed beams
As for calculating a flat slab using beams...not advisable. Yes, they use bending theory, but the bending stiffness of plates and beams are calculated differently. Plates use D=(E*h^3)/(2(1+v^2)) or something like that...trying to recall from memory. For the beam method, you would use EI.
You can derive the plate bending from beams, but you have to do some pretty high-end partial derivatives and superposition.
Is there a reason why Roark's formulas won't work?
RE: Analyzing a slab as crossed beams
What kind of slab do you have?
RE: Analyzing a slab as crossed beams
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
RE: Analyzing a slab as crossed beams
I've seen people do this before where they assess complex shapes as a series of beams and think it gives the right answer. It's difficult to convince them otherwise, but any answers you get would be rubbish in my opinion.
corus
RE: Analyzing a slab as crossed beams
E C Hambly, ‘Bridge deck behaviour’, E & F N Spon, Second Edition, 1991.
RE: Analyzing a slab as crossed beams
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
RE: Analyzing a slab as crossed beams
This is a two-way concrete slab with geometry irregulrity.
RE: Analyzing a slab as crossed beams
The panel was fastened down all around its edges.
The beams were at a fixed pitch with about a dozen of them across the smallest panel dimension.
Panels designed in this way (with appropriate load factors) saw decades of successful service.