Abaqus - Finding indentation size/shape across 150 simulations
Abaqus - Finding indentation size/shape across 150 simulations
(OP)
Hi all,
I have been using Abaqus for a relatively short time, and I am using it to simulate the effects of the variation of three different parameters on the collapse capacity of subsea pipelines. This will involve first indenting the model, and then seeing how these indentations/imperfections affect the collapse pressure/capacity.
I am currently trying to script this so that roughly 150 simulations of indentation will be undertaken (3 values of parameter A, 7 values of parameter B, 7 values of parameter C). (so there may be 150 simulations of indentation and then 150 more simulations of collapse to find what pressure the indented models collapse at)
As part of this, I need to extract and analyse data relating to the size and shape of the 150 indentations. Do you have any recommendations or pointers on how to do this? And how to post-process this information to find out the dimensions/shape of the various indentations?
I have thought of creating a node set around the area to be indented, and then using the coordinates of those nodes (before and after indentation) to get the size/shape. But, this will result in a large amount of information due to the number of nodes, and I was wondering if there may be 'simpler' way that is less computationally expensive. I understand how to automate the 150 simulations, but not the best way to collect the desired info.
I have attached a photo of my indentation model for reference. (The node set I planned to take coordinates of is contained within the two datum planes either side of the indenter)
Many thanks.
I have been using Abaqus for a relatively short time, and I am using it to simulate the effects of the variation of three different parameters on the collapse capacity of subsea pipelines. This will involve first indenting the model, and then seeing how these indentations/imperfections affect the collapse pressure/capacity.
I am currently trying to script this so that roughly 150 simulations of indentation will be undertaken (3 values of parameter A, 7 values of parameter B, 7 values of parameter C). (so there may be 150 simulations of indentation and then 150 more simulations of collapse to find what pressure the indented models collapse at)
As part of this, I need to extract and analyse data relating to the size and shape of the 150 indentations. Do you have any recommendations or pointers on how to do this? And how to post-process this information to find out the dimensions/shape of the various indentations?
I have thought of creating a node set around the area to be indented, and then using the coordinates of those nodes (before and after indentation) to get the size/shape. But, this will result in a large amount of information due to the number of nodes, and I was wondering if there may be 'simpler' way that is less computationally expensive. I understand how to automate the 150 simulations, but not the best way to collect the desired info.
I have attached a photo of my indentation model for reference. (The node set I planned to take coordinates of is contained within the two datum planes either side of the indenter)
Many thanks.
RE: Abaqus - Finding indentation size/shape across 150 simulations
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
Many thanks for your reply, it is very helpful.
Do have any links any guides on processing nodal data from Abaqus using Matlab? It isn't something I am familiar with.
Also, the node set I will be taking coordinate data from contains roughly 4000 nodes (which will each have an x,y,z value), do you think this is a manageable number that will be able to be processed by matlab?
Thanks
RE: Abaqus - Finding indentation size/shape across 150 simulations
RE: Abaqus - Finding indentation size/shape across 150 simulations
I'd use Matlab purely because it is what I'm familiar with, given a clean sheet of paper perhaps Python would be nicer.
https://abaqus-docs.mit.edu/2017/English/SIMACAEOU...
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
"You could use the deformed coordinates (COORD output variable) to filter out elements belonging to the indentation"
Does the COORD output variable only get coordinates of nodes that have been displaced then?
Thanks
RE: Abaqus - Finding indentation size/shape across 150 simulations
RE: Abaqus - Finding indentation size/shape across 150 simulations
RE: Abaqus - Finding indentation size/shape across 150 simulations
RE: Abaqus - Finding indentation size/shape across 150 simulations
One of the excellent book resource for beginners in python scripting-"Python Scripts for Abaqus - Learn by Example" by Guatam Puri.
Edit - Another resource for MATLAB - "Introduction to Finite Element Analysis Using MATLAB and Abaqus" by Amar Khennane
RE: Abaqus - Finding indentation size/shape across 150 simulations
After searching and reading some material online, I will use MATLAB to process my results. I have found a useful piece of software called Abaqus2Matlab. It seems to do some of the legwork for you, and allows you to import results into MATLAB for analysis.
As suggested, I am going to try and analyse just one result first. Once that has been done, then I will try to extend that analysis/post-processing to the other ~150 simulations.
https://abaqus2matlab.wixsite.com/abaqus2matlab
RE: Abaqus - Finding indentation size/shape across 150 simulations
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
clc
tic% create a 2d grid of deformation vectors
a=rand(4000,3);
%get their magnitudes
b=sqrt(sum(a.*a,2));
%list all the elements with magnitude in top 5%
c=find(b>.95*max(b));
disp(c)
%list the %ages
disp(b(c)*100/max(b))
toc
disp('Fit 3900 quartic splines')
tic
breaks = [1:9:100];
for ii=1:(length(a)-100)
xspline=1:100;
y=b(xspline+ii-1);
yspline=splinefit(xspline,y, breaks,'order',4);
end
toc
%plot the last splinefit
plot (xspline, y, "s", xspline, ppval (yspline, xspline), "r", breaks, ppval (yspline, breaks), "+r");
xlabel ("Independent Variable");
ylabel ("Dependent Variable");
title ("Fit a piece-wise polynomial of order 4");
legend ({"data", "fit", "breaks"});
axis tight
ylim auto
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
Thank you for your reply. My apologies, but would you mind explaining how output information from Abaqus (node number, node coordinates, node deformation) would fit into the code you posted?
I am guessing that my output info from ABAQUS would go here, becoming the variable 'a':
"% create a 2d grid of deformation vectors
a=rand(4000,3);"
My model is also a 3D model, but I assume the principles of the script would be similar?
Many thanks,
Edward
RE: Abaqus - Finding indentation size/shape across 150 simulations
I have uploaded my model in the form on an input file, I have been unable to use Abaqus2Matlab due to software installation issues.
Would someone be able to look at my model and give me some guidance on how to extract the coordinates data I need? I have requested coordinates and displacement data as a history output from the chosen node set, but I am not sure how to output the results via scripting. Manually using the graphical interface, I have created a display group and probed by the node set, but that will not work for the large number of simulations I will be performing.
Many thanks,
Edward
RE: Abaqus - Finding indentation size/shape across 150 simulations
That script I posted was to reassure you that 4000 calculations is not really a speed problem, it doesn't really do what /you/ need to do.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Abaqus - Finding indentation size/shape across 150 simulations
I understand now, thanks.