numerical modeling of concrete in abaqus
TRANSCRIPT
Ad 1st assignment
Open Abaqus
Click on part :-
Click continue :-
Center 0,0 and press Enter
A point on perimeter & press Enter
Now click here
Now here
Enter length of cylinder & Click OK
Obtain a beautiful cylinder
Go here click properties
Click Create Material
Click General - > Density
yield stress inelastic strain
2652974.61 0
3094436.04 0.000103295
13686557.6 0.00048805
21909750.7 0.000954491
26216831.2 0.001555971
26902245.8 0.002282336
25368514.1 0.003085224
22908785.7 0.003920042
20287294 0.004760438
18503462.3 0.00536195
Copy – Paste the Given Values ……….. Getting these values I’ve told in excel sheet attached
yield stess cracking strain
1595000 0.00E+00
981831.7496 0.000151144
798658.4402 0.00028246
697445.153 0.00041095
630420.827 0.000538261
581606.8791 0.000664945
543890.8538 0.000791245
513548.0906 0.000917291
488408.7289 0.001043158
467109.2021 0.001168893
448742.5432 0.001294526
432678.1885 0.00142008
410675.3731 0.001620839
damage parameter cracking strain
0 0.00E+00
0.05 0.000151144
0.1 0.00028246
0.15 0.00041095
0.2 0.000538261
0.3 0.000664945
0.4 0.000791245
0.5 0.000917291
0.6 0.001043158
0.7 0.001168893
0.8 0.001294526
0.9 0.00142008
0.95 0.001620839
Click OK
Select the cylinder and click done
1.For rigid platen put U1=0, U2=0 at both surfaces & U3=0 on the opposite surface of loading. 2. For Soft platen put only U3 = 0 on the opposite surface of loading.
I’m solving only for rigid platen.
Rotate cylinder to put U1=U2=U3=0 on the opposite side of loading for rigid platen. For soft platen it would be only U3=0.
Loading surface…..U1 =
U2=0, U3≠0
Fixed surface…U1=U2=U3=
0.
Now we will apply load on the loading surface.
Rotate & Select this top surface
Remember I told that loading time should be consistence with step time……Here please note that Time span should be “Total time ”
not “Step time” so that in 0.1 sec loading will become 100%
Click OK
Applied pressure > 27Mpa / area
=27e6/(3.14 X 0.15^2/4) = 0.1528 e 9
1. We Have almost done but we have not defined yet damage parameters which will tell us, whether our concrete has failed or not. 2. To plot load vs disp graph we have to plot total reaction at the bottom vs disp of the top point where load was applied. So this point I’m going to mark as reference point.
Reaction here
displacement here
We have to create two sets 1. For top surf disp.
2. For reactions Go to Tools->Set->Create
Marking Surf for disp.
Rename it to “top_surf” and click continue
Select top surf and click done. I’ve created a RP at the center but it’s
useless u can skip it.
Again go to Tools-> set- > Create and create 2nd set and give name as Reactions
Select bottom surface and click “Done”
We have create sets for load vs disp graph but we have not told
Abaqus to give me output for these sets yet.
Let’s 1st use the sets that we have just created and tell abaqus to give me
reactions as well top surf disp.
Output -> History output Request-> create
Let’s name this as “Tip-disp”
Again Output -> History output Request-> create
Let’s set damage failure parameters Output -> Feild output Request-> create
We have to make it independent to mess it. Right click on Part 1-1 and select -> Make Independent
This is quite big mess. You can refine it for convergence study. To do this reduce seed size from 0.021 to 0.01 in
slide no.73
OK Take rest now.
Analysis Got aborted due to errors let’s check error.
This is bcoz I’ve taken taken fcr = 3.65* sqrt(fck) in tensile properties. If you will take it above 4.5 rather 3.65 you will not get this error and also reduce mess size. Lets’s
check results with this data.
DAMAGET :- TENSILE FAILURE DAMAGEC:- Compression failure
Sdef :- Stiffness Degradation
Lets’s plot Load vs disp graph
Select All RF3 and click Save As
We are using ssum bcoz we have to add all reactions
Again for disp.
Select all U3 and click save as
This time we will not use ssum rather we will use avg.
Click OK
Here my disp and rxn data has come
Load vs disp graph
Failure load = 0.4e6 Pressure = 0.4e6 /(area)
= 22.64Mpa < 27 Mpa(given in prob. statement) Prob. is in the properties.