Jorgen
Administrator

Dear Dr Jorgen

I am so grateful.
thank you very much

I have sent two private messeges for you

please read these messages

Dear Dr Jorgen

happy new year

I have sent an e-mail for you

please help me

hi Dr Jorgen

if you please, how can i get the (drucker and prager constitutive model) in fortran code which, implemented (built in) in ABAQUS FINITE ELEMENT code. I need this model to modify it for modeling a soft soil in braced excavation application with small strain stiffness application (importing young's modulus as a function of strain and changing the stiffness after yielding occur)

Dear Dr. Jorgen,

I found this thread http://polymerfem.com/forums/showthread.php?t=833 with indentation input file for Abaqus. I model similar things in Adina and have problems for large strain case, therefore before finishing PhD thesis in couple of months, i would like to quickly try Abaqus.

I thought to use input file from mentioned above thread, but it contains more than 20 000 nodes and therefore I can't run it on our license.

Could you be so kind and give me couple of hints how to make similar (orphan) mesh from scratch or maybe a link to some resource.
All I find in internet (tutorials) are much more simple in terms of meshing. HTML documentation is not that useful either - i have not found step-by-step examples for that kind of meshing.

Thank you in advance,
Best regards,
Denis Davydov,
PhD student, Czech Technical University

dear Jorgen,

Hi, I would like to check the constraint effect on the hydrogel filler (circle) in another hydrogel matrix (rectangular block). The estimated elastic modulus is around 5kPa. Unfortunately, it does not work in ABAQUS/standard. Then I run it in ABAQUS / explicit. Although the simulation complete successfully, but the result doesn ot look correct. The interesting bit is that if I change the materials properties to steel & Al it works well.

Could you please give me some advice on this ?

I am eager to your kindest help !

The input desity is 1100.

Great thanks in advance !

Sorry, I do not know how to attach the images. It seems that I need URL to attach the figs. Could you please tell me how to do this so that I can send you the images ?

Thanks !!!!

vicky

Hallo

I am running some FEA on a tube model made by silicone .I down loaded the data for the uniaxial compression in order to input them into abaqus.

1) Do you know where i could find data for biaxial test?
2) What was th type of the silicone used in the uniaxial test that i downloaded?

Thank you in advance
Orestis

Hello Jorgen,
I need practical suggestion..
I make simulation with rubber pipe with flowing steady silicon oil inside and an external pressure applied on the pipe which results in large deformation. I would like to perform Fluid Structure Interaction simulation using Ansys (Workbench) and CFX sortware.I applied the material properties(like the youngs modulus,poissons ratio,density of rubber) and ran the simulation without FSI but resulted in the below error message:
"solver pivot warnings have been encountered during the solution.This is usually a result of an ill conditioned matrix possibly due to unreasonable material properties, an under constrained model or contact related issues. Check results carefully!"

When i take FSI into account it says "one or more elements are getting excessive distortion".
Could you please suggest something,
Divya

nice to meet U

Dear Mr.Jorgen,
I need to perform"Flexible Dynamics Analysis" using Workbench Simulation. The material which I consider is a silicone pipe which represent a blood vessel. Actually I am interested in Fluid Structure Interaction calculations. I am goind to use for it Ansys CFX and Ansys Structural(= Workbench Simulation).But in this time I have some problems with calculation of structural part of the pipe. That why at the beginning I want to perform calculations only for structural part of the pipe - without Fluid-Structure Interactions.
I wonder, do you have a guideline for performing all steps necessary for this analysis?
I have found some information about it in ''Ansys Help'' but due to special properties of the silicone I don't understand which parameters I should apply for my case. Could you give me any tips, please?
Thanks in advance!
Best regards,
Natly

Dear Mr. Jorgen
I need a basic understanding from your side regarding UMAT code for Single crystals
I was following a paper on the same and it says that ABAQUS provides for each integration point, the values of total deformation gradient, F at the
current time t, the deformation gradient from the current natural configuration, Fe at
current time t, current value of the Cauchy stress, T and the state variables such as
s(strain path length) and G(Plastic Deformation) at the current time step. It also sends an estimate of the total deformation gradient at the next time step (t + ∆t).

The UMAT supplies the values of the state variables such as s, Fe and G and Cauchy stress at time step t + ∆t and return it back to the ABAQUS. This process continues until the a converged solution is obtained

Thus I would like to know how can we provide G, Fe and T at time step t + ∆t. I know how to get s from the constitutive equations.
Any help would be appreciated
Thanx