Smearing rebar material properties
Smearing rebar material properties
(OP)
Is there an equation to smear the modulus of elasticity of rebar on a solid element.
I have a 3D model of a concrete structure and only the concrete is modeled as an isotropic material. The natural frequency is coming out to be too low. I wanted to smear the stiffness of rebar without changing the element type to a concrete element. Is there a easy way of doing this.
Thanks,
I have a 3D model of a concrete structure and only the concrete is modeled as an isotropic material. The natural frequency is coming out to be too low. I wanted to smear the stiffness of rebar without changing the element type to a concrete element. Is there a easy way of doing this.
Thanks,





RE: Smearing rebar material properties
E(composite)=E(concrete) AREA(concrete) + E(steel) AREA(steel)
and
AREA(concrete)=1.0-AREA(steel)
AREA(steel) = % steel expressed as a decimal i.e. 1%=.01
Ed.R.
RE: Smearing rebar material properties
Garland E. Borowski, PE
Borowski Engineering & Analytical Services, Inc.
Lower Alabama SolidWorks Users Group
Magnitude The Finite Element Analysis Magazine for the Engineering Community
RE: Smearing rebar material properties
Don't you mean the following:
E(composite)=
E(concrete) AREA(concrete) + E(steel) AREA(steel)
TOTAL AREA
??
RE: Smearing rebar material properties
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.
RE: Smearing rebar material properties
GregLocock,
I don't understand the neutral axis if its being modeled with solid elements
Thanks,
RE: Smearing rebar material properties
Nope...By defining the Area's as I did the total area becomes 1.0 and you don't have to consider the total area of each element.....
rh142:
It's probably a decent first approximation to use the same idea for the shear modulus...Once you have E and G Poisson's ratio's are defined.....You may have to look up the orthotropic (anisotropic?) relationships between E, G, and Nu....
Greg:
True if bending is present...Typically when using this technique the element size is controlled so that the smeared properties are representative of each region (and as Garland said also in each direction) ...Thus if bending was present one would have multiple elements, each with a different % of steel, to represent the various regions....The technique can be extended to bending elements by extending the "transformed section method" of composite materials but it becomes complicated.....
Ed.R.
RE: Smearing rebar material properties
RE: Smearing rebar material properties
Cheers
Greg Locock
Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.