HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
(OP)
Hi, guys.
Any of you know how to determinate the MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Any of you know how to determinate the MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?






RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Using a steel tube with:
- 140 mm of external diameter and 130 mm of internal diameter;
- E = 200 e9 Pascal;
- DENS = 7850 kg/m³
Filled with concrete with:
- E = 26.3 e9 Pascal;
- DENS = 2400 Kg/m³
what the Equivalent Modulus of Elasticity??
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Equate the deflection of the pipe and the concrete and solve for an equivalent composite section elastic modulus.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
So, presuming that the concrete wont crack. How can i determinate the equivalent elasticity modulus for a equivalent composit section?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Find area of concrete (Ac).
Sum the two areas (At).
Take weighted average of E.
(As/At)*Es + (Ac/At)*Ec = 50.3E3 MPa.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
But where you got that formula??
And how can i calculate the equivalent poisson ratio??
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
So are you interested just in stiffness under axial load, or also bending?
If you need bending stiffness as well, it gets more complicated. See for instance:
http://ccvi.ce.gatech.edu/Papers%20March%20PDF/Whe...
But for a lower bound estimate you could ignore the concrete.
Doug Jenkins
Interactive Design Services
http://newtonexcelbach.wordpress.com/
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Never looked myself but I know of atleast one steel high rise in Brisbane that the steel filled tubes were designed to the Eurocodes.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
With some difficulty I imagine. As an approximation, you could workout the steel hoop strain associated with restraining the dilation of the concrete. While inexact, this should give a reasonable characterization of the composite poisson ratio.
What is the nature of the thing that you're designing? Are you simply seeking appropriate values for use in modelling software?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Anyone have a ideia?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I am modeling a transmission tower using steel tubes filled with concrete on the amounts and corner frames for every other element of the tower.
I am modeling that on ANSYS. My code for that its on attachment.
My questions is:
1) It`s correct the affirmation from Trenno to get the equialent modulus of elasticity?
2) How can i get the equivalent density of the element?
3) How can i get the equivalent poison`s ratio?
4) Can i use the element beam188 - SECDATA - CSOLID, using the equivalent properties?
5) The model using the answer of the question 4 will give me the right frequencies of my problem?
The code on attachment its from a tower using corner frames and tubes on amounts (GROUP = MONT).
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
Probably. You should run the weighted average calc for your self to verify Trenno's work.
Again, use a weighted average.
See my previous post for a possible estimation procedure.
I'm afraid that I'm not familiar with these elements.
I'm afraid that I'm not familiar with these elements.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I`ll calculate my self, scam and post it here to you see. ok?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I've never tried to do this in software so I'm afraid that I'm unable to be of much help regarding your ansys element choices.
Sure.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
2. Looks good.
3. Probably incorrect. I don't feel that weighted average is appropriate here. See my recommendation above.
4. I can't say. Hopefully someone else here with better FEM chops can comment.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
v freq (Hz)
0,21 1,146
0,22 1,145
0,23 1,145
0,24 1,144
0,25 1,144
0,26 1,144
0,27 1,143
0,28 1,143
0,29 1,142
what you think about this results? Its better use a Poison`s ratio between 0,24 to 0,26?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
You've varied your poison's ratio by around 27.6% difference.
Now within that range, your frequencies have only varied by around 0.35% difference.
What does that tell you?
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
The smooth face of the inside of the pipe and the inherent shrinkage of the concrete during curing seems to indicate there there is not any real bond (if any). The wetter the concrete for pumping coupled with the normal shrinkage of all concrete seems to present a problem with any kind of bond for composite construction.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.
RE: HOW TO DETERMINATE THE MODULUS OF ELASTICITY OF A STEEL TUBE FILLED WITH CONCRETE?
No code I've ever seen uses a weighted average like has been discussed here. Usually some sort of sum of the concrete and steel modulus and second moment of inertia is calculated i.e. sum of E x I, this is sometimes modified to bring the stiffness in line with real world tests. I believe the stiffness of the composite member is pretty well understood in terms of research, so this approach is outlined in a number of international codes relating to the design of composite concrete filled sections.
Refer to the attached (page 16) for an example of how a code approaches this, this document is based on the previous revision of Eurocode 4. But the same principles apply in the latest version with some minor changes.
The Australian Bridge code AS5100.5 also has a similar derivation which I am more familiar with, this standard is based on Eurocode 4 with some small changes to make it more New Zealand/Australian-ised.