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  1. nonlinearRus

    Using discrete rigid elements in thermal analysis?

    Hi all, I'm running a coupled temp-displacement model and I'm trying to debug the model at the moment. The model consists of a hyperelastic and viscoelastic material (foam) being compressed by a (simple) indenter. I had been using steel as the material for the indenter and it gave accurate...
  2. nonlinearRus

    Automating Abaqus jobs

    Thanks for your advice. Maybe that is the best way to do it. Do you know of anyway I can create batches of input files then if I have a list of parameters that I want to run with? Just changing one parameter per input file. Then I want to run each job from Matlab, and then look at results in...
  3. nonlinearRus

    Automating Abaqus jobs

    Hi, I have my model mesh optimized and running well. I now need to run a sensitivity analyses on some parameters within the model and then optimize the results of some other parameters once this is completed. I was thinking of trying to write the changeable parameters as variables within the...
  4. nonlinearRus

    Contact with Membrane elements

    Hi all, I am trying to model a seating system in Abaqus CAE. I'm using a hyperelastic+Visco model to model the behaviour of the foam and for now I'm modelling the person sitting as a hard wooden material. My model is working quite well for now but my results are a bit off as I have not modelled...
  5. nonlinearRus

    Controlling Abaqus within a C++ app

    Hey mechfeeney, I've been working on a simulation for a while now within .CAE and I have it working nearly 100% as I would like. I was just wondering do you think it would be handier for me to run batches of jobs (optimization) using an external Matlab script or some sort of python Abaqus...
  6. nonlinearRus

    Applying load in Abaqus

    Hi, Thanks for you reply, but I can't seem to open either of your links. Maybe I should have explained my problem in a bit more detail.. I have two bodies, one rigid, one a flexible NL material. Originally I had applied a non-zero displacment to push the rigid body into the flexible body and...
  7. nonlinearRus

    Applying load in Abaqus

    Hi all, I am just wondering what is the best method of applying a distributed load in the CAE solver in Abaqus? I have been trying to apply body forces, using amplitudes which break my steps up into smaller steps but and my model still crashes with too many increments. Has anybody any idea why...
  8. nonlinearRus

    Material Curve Fitting/Paramters

    Hi all, I'm trying to model a polyurethane foam in compression using the hyperfoam model in Abaqus. I'm doing the analysis for a comparison with other finite element packages, so I am quite new to Abaqus but I am familiar with finite element modelling in general. I'm trying to find the...
  9. nonlinearRus

    Inaccurate fit of Hyperfoam material model

    I've now fitted the data to the negative values and the plot is still titled uni-axial tension. I'm still trying to get the MatLab optimization working properly though, and if I can't get much success I will look further into MCalibration - as it looks like a very useful tool. I have a...
  10. nonlinearRus

    Inaccurate fit of Hyperfoam material model

    A much better fit alright! But I'm sure it could be better if I could optimize the parameters. So I've been trying to use the lsqcurvefit tool in Matlab Optimization toolbox, with little success! My data is actually for uniaxial compression of a foam sample. The data was input into the...
  11. nonlinearRus

    Inaccurate fit of Hyperfoam material model

    Here is the new curve fithttp://files.engineering.com/getfile.aspx?folder=1e3b2d49-89ff-4350-a2fd-7fee6bfe45f9&file=Eng_tips.png
  12. nonlinearRus

    Inaccurate fit of Hyperfoam material model

    The black curve is actually the exp data, I don't know why but ANSYS somehow titles it as the model and titles the model as the experimental data. I've just tried using the same model, increasing and fixing the Mu1 value (which controls the initial rise in the curve's elastic region). The curve...
  13. nonlinearRus

    Inaccurate fit of Hyperfoam material model

    Hi all, I am trying to fit a 2nd order Ogden Hyperfoam material model to my experimental data. The material is compressed uni-axially. The model doesn't seem to be a 2nd order model, and looks more like a 1st order N-H model. Also the Mu1,Mu2 and Alpha1,Alpha2 values are the same. Can anybody...
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