Hello Gyan
In my experience, the model presented by Hinton & Owen with modification
to tension stiffening (adjusted to modify the rebar quantity in the tension
zone)
 is suitable for modelling concrete non-linearity. However
I have found lots of problems in the past when  I tried to use the option
of
'user defined subroutine' in commerical software. The problems encountered
depend on the degree of non-linearity and the type of problem you are
analysing.
In analysing shells and plates, I found that the convergence and mesh
objectivity
play a significant role and could pose numerical problems.
regards
ganga

G Prakhya, Ph D (Cambridge), M Tech, CEng MICE
Chief Structural Analyst
Technical Services
Sir Robert McAlpine Ltd
Eaton Court
Hemel Hempstead






Marc Quint <[log in to unmask]>@JISCMAIL.AC.UK> on 25/02/2002 10:21:38

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Subject:  Re: Reinforced Concrete model


Hello Gyan,

it depends on what you need to know as results from your analysis.

It is common practice to model concrete structures with nominal cross
ansectional properties and a constant Young's modulus and use formulas
for the design that account for "concrete dependant" influences.

If you want to make it more complicated you can add:
- cracks (discrete or "smeared")
- non uniform Young's modulus for concrete (over time as well as load
depending)
- non-rigid shear modulus for the rebar-concrete interface
- creep, shrinkage
- microscopic, micro and macro effects of the cement-gravel-sand
interface/material
- discrete representation of rebars and anchorage
- ...

One advice:
Stay with the ideal elastic model and the tables and formulas for the
determination of reinforcement for normal forces, bending moments,
torsional moments and shear forces.

If you have plenty of time and no monetary restrictions you can try any
of the others.

Sincerely yours,

Marc Quint


Dipl.-Ing. Marc Quint  VDI
Structural Design
Kaiserstrasse 85
72764 Reutlingen
Germany
T +49-7121-339245
F +49-7121-339123
[log in to unmask]


Gyan Pande wrote: Dear All

Does any one know of a good model for reinforced concrete which may be
plugged in ABAQUS ?

G. Pande
Computers & Geotechnics Ltd




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