Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed: https://answers.launchpad.net/yade/+question/704293 Status: Open => Expired Launchpad Janitor expired the question: This question was expired because it remained in the 'Open' state without activity for the last 15 days. -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed: https://answers.launchpad.net/yade/+question/704293 Leonard gave more information on the question: Hi Karol, Many thanks for your reply. Here are the output with triangulation part (i.e. not comment out) # Triangulated Grains : 33 sym_grad_u_total_g (wrong averaged strain): 0 0 0.125 0 0 0 0.125 0 0 Total volume = 8, grad_u = 0 0 0 0 0 0 0.25 0 0 sym_grad_u (true average strain): 0 0 0.125 0 0 0 0.125 0 0 Macro strain : 0 0 0 0 0 0 0 0 0 Here below are the output without triangulation part (i.e. comment out): ### Triangulated Grains : 33 sym_grad_u_total_g (wrong averaged strain): 0 0 0.125 0 0 0 0.125 0 0 Total volume = 8, grad_u = 0 0 0 0 0 0 0.25 0 0 sym_grad_u (true average strain): 0 0 0.125 0 0 0 0.125 0 0 Macro strain : 0 0 0 0 0 0 0 0 0 # In addition, the two vtk files are visulised in paraview and they look the same. Thanks Leonard -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed: https://answers.launchpad.net/yade/+question/704293 Karol Brzezinski posted a new comment: Sorry, but I am 'computerless' right now, and I cannot check it to confirm. Can you please take the above example, comment out the triangulation part and see if you get the same results? Cheers, Karol -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed:
https://answers.launchpad.net/yade/+question/704293
Status: Answered => Open
Leonard is still having a problem:
Hi Karol,
Thanks very much for your reply and the nice reference example.
>>You still need to triangulate and compute volumes
Maybe it would be better to clarify my doubt: I think TW.triangulate()
and TW.computeVolumes() are only needed in the approach of using
TW.setState(0) TW.setState(1). While in the approach of using
TW.defToVtkFromPositions( 'sp0.txt','sp1.txt' ,
'strain_from_files.vtk'), TW.triangulate() and TW.computeVolumes() are
not needed.
Taking your example, now we don't compare the two approaches, but we
compare the approach of using TW.defToVtkFromPositions with/ without
triangulate and compute volumes:
centers = []
for x in range(3):
for y in range(3):
for z in range(3):
centers.append((x,y,z))
O.bodies.append([
sphere(center=center,radius=1,) for center in centers
])
sp = SpherePack()
sp.fromSimulation()
TW=TesselationWrapper()
# TW.triangulate() ## without triangulate
# TW.computeVolumes() ## without compute volumes
sp.save('sp0.txt')
shiftBodies(list(range(18,27,1)),(0,0,0.5)) # move one layer of spheres
without engines (I am just being lazy)
sp.fromSimulation()
sp.save('sp1.txt')
TW.defToVtkFromPositions( 'sp0.txt','sp1.txt' , 'strain_from_files2.vtk')
The above example uses TW.defToVtkFromPositions without triangulate and
compute volumes, and the vtk file visualised in paraview seems to be the same
as TW.defToVtkFromPositions with triangulate and compute volumes.
Thereby, I think it is not needed to triangulate and compute volumes
when use TW.defToVtkFromPositions(). Please correct me if I
misunderstood.
Thanks
Best regards,
Leonard
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Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed: https://answers.launchpad.net/yade/+question/704293 Status: Open => Answered Karol Brzezinski proposed the following answer: Hi Leonard, Regarding your questions: 1. Yes - the order of spheres in files must be identical. 2. You still need to triangulate and compute volumes. Sorry, if it was not clear previously linked topic. Please see the example provided here [2]. Two approaches are compared on one example, but the code should be self-explanatory. Cheers, Karol [2] https://answers.launchpad.net/yade/+question/696150 -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed:
https://answers.launchpad.net/yade/+question/704293
Status: Answered => Open
Leonard is still having a problem:
Hi Karol,
Haha, thanks for addressing this question again.
Just two things to be confirmed to make sure I correctly understood:
1. In the two txt files, each line (which is the x, y, z, radius of a
sphere) should be the same sphere. e.g. If sphere id 10 is at the 10th
line in txt1, it should also be at the 10th line in txt2.
2.When I input the two txt files into defToVtkFromPositions(), I use the
2 lines of code as below:
TW=TesselationWrapper()
TW.defToVtkFromPositions("txt1.txt","txt2.txt","def.vtk")
without TW.triangulate() which has been used in example [1]. I'd like to
confirm that when we use defToVtkFromPositions(), there is no need to
involve TW.triangulate().
Please correct me if I am wrong.
One question is that, when I execute TW.defToVtkFromPositions(), it
returns a Macro strain and it is always:
0 0 0
0 0 0
0 0 0
in all of my states against initial state in a triaxial compression test. Even
I can observe strain_deviator difference in paraview at different states. May I
ask what is Macro strain and why it is a zero matrix in my case.
Thanks
Best wishes
Leonard
[1]https://yade-dev.gitlab.io/trunk/user.html#micro-strain
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Re: [Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
Question #704293 on Yade changed: https://answers.launchpad.net/yade/+question/704293 Status: Open => Answered Karol Brzezinski proposed the following answer: Hi Leonard, How about strings the packing at different states in external txt files, and computing strains between pairs of files? [1] Best wishes, Karol [1] https://answers.launchpad.net/yade/+question/700439 -- You received this question notification because your team yade-users is an answer contact for Yade. ___ Mailing list: https://launchpad.net/~yade-users Post to : yade-users@lists.launchpad.net Unsubscribe : https://launchpad.net/~yade-users More help : https://help.launchpad.net/ListHelp
[Yade-users] [Question #704293]: How to use TW.triangulate() to calculate strain between two states by importing samples
New question #704293 on Yade:
https://answers.launchpad.net/yade/+question/704293
Hi,
I'd like to ask that how to use TW.triangulate() to calculate strain between
two states by importing the two samples at the corresponding states.
The approach of calculating micro-strain between state 0 and state 1 is
mentioned at [1], the main steps are as below:
###
O.load("test.yade") ## import sample
TW.setState(0) #store current positions internaly for later use as the
"0" state
O.run(100,True) #make particles move a little (let's hope they will!)
TW.setState(1) #store current positions internaly in the "1"
(deformed) state
TW.defToVtk("strain.vtk")
###
The above code works well during a simulation.
However, I have carried out a series of triaxial compression tests and I saved
samples at different axial strain levels (e.g. at strain 0%, 10%, 20%). I
wonder if I can use TW.triangulate() to calculate the micro-strain between
strain10% and strain20% (or any of the two strain states). If it is possible,
it will save a lot of time as I don't need to re-run all the tests again.
something like (pseudocode):
###
O.load("sample_strain0.yade")
TW.setState(0) #store current positions internaly for later use as the
"0" state
O.load("sample_strain1.yade")
TW.setState(1) #store current positions internaly in the "1"
(deformed) state
TW.defToVtk("strain.vtk")
###
Thanks!
Leonard
[1]https://yade-dev.gitlab.io/trunk/user.html#micro-strain
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