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  1. robidpra

    Moving temperature boundary condition subroutine

    I have added a reference point, that is uncoupled from the model. Then I employed an MPC between this reference point (master) and all nodes (slave). The reference point was held to a fixed temperature with a boundary condition. The MPC user subroutine contained IF([CONDITIONS]) THEN...
  2. robidpra

    Moving temperature boundary condition subroutine

    Yes I tried DISP, but it did not work. The problem is that you cannot deactivate the DISP subroutine, you have to provide an amplitude.. I'm looking into MPC now
  3. robidpra

    Moving temperature boundary condition subroutine

    Sure, The error encoutered was ***ERROR: *TEMPERATURE MAY NOT BE USED WITH ELEMENTS THAT POSSESS TEMPERATURE DEGREES OF FREEDOM. USE *BOUNDARY TO PRESCRIBE BOUNDARY CONDITIONS ON TEMPERATURE I use a coupled temperature-displacement analysis, with corresponding...
  4. robidpra

    Moving temperature boundary condition subroutine

    Would it be possible to employ the MPC subroutine to give certain nodes a certain temperature?
  5. robidpra

    Moving temperature boundary condition subroutine

    The process I want to simulate involves a fixed temperature boundary condition rather than a certain heat flux. I can try to calculate the corresponding heat flux for a certain temperature but this process could be complicated I guess.
  6. robidpra

    Moving temperature boundary condition subroutine

    Hi all, I'm trying to figure out something. I have a coupled temperature-displacement analysis with a UMAT & UMATHT subroutine. The UMAT describes the mechanical behaviour, and the UMATHT describes the heat conduction. I want to introduce a boundary condition for the temperature when certain...
  7. robidpra

    Implementing anisotropic plasticity in UMAT

    Hello, I'm looking into implementing anistropic plasticity in ABAQUS. I know the Hill criterion is implemented by default in ABAQUS (see abaqus docs), but I want to implement it in a UMAT, because I have to couple it with other features. Regarding the STRESS variable that I can use in a UMAT...
  8. robidpra

    Increment size at specific times

    How does this 'time points' feature works? Does ABAQUS controls the increments such that the exact time points are reached? Or is it purely interpolation based on the converged increments?
  9. robidpra

    Increment size at specific times

    Hello, For my model, I have implemented a UMAT, and at the end of each converged iteration, a parameter is calculated. The UMAT calculations need this parameter for further calculation. So the values of my UMAT at time increment i depend on the parameter calculated in increment i-1, i.e...
  10. robidpra

    Access to nodal stress values during UMAT

    I tried something now with URDFIL: First I adapted my input file to write the stress invariants to the results .fil file, (Using *EL FILE). And after each increment, URDFIL reads in the stress invariants from the .fil file, and saves it into a common block.
  11. robidpra

    Access to nodal stress values during UMAT

    I did some test simulations, and I got for example this element: So the pressure values on this element range from -260 to -393 MPa if you look at the nodal values (see the legend), but if I extract the pressure values on the integration points, they only range from -323.9 to -323.3. This will...
  12. robidpra

    Access to nodal stress values during UMAT

    Hello, I'm currently writing a UMAT. The constitutive equations of the material are based on the gradient in pressure stress (∇p) of the previous increment. I know it's possible to access the pressure stress at the integration points in the UMAT, but with some test simulations (C3D8 elements)...

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