Have you tried combined/kinematic hardening (*PLASTIC, HARDENING=COMBINED.. and *CYCLIC HARDENING in ABAQUS old money)?
Agreed, it's mainly for metal plasticity but perhaps worth a try.
You could quickly use a single element model to attempt to fit its behaviour to your test results...
Points loads on a node and plasticity together are not a good idea. You'll probably find that you have excessive yielding around the load. That's perhaps why your displacement (at load point?) is larger than the test value.
Try distributing the point load over a larger area, or make a small...
Robert,
For the model you'll need at the very least the elastic modulus and Poisson's ratio of the epoxy. If the test shows significant non-linear behaviour prior to fracture you'll also need the plastic behaviour in terms of say (yield) stress versus equivalent plastic strain. Do you have such...
You have plane strain elements with both ends fixed. Therefore, the individual components of stress can exceed the yield stress according to the yield criterion. The ENCASTRE boundary condition will certainly help to elevate the individual components of stress. Note, however, that the von mises...
I don't know a lot about crushable foam, but I suggest you review the measured material data. I think you really need more measurement points.
Also, if you take the first "leg" of the red strain-strain curve as elastic behaviour: that would suggest an elastic modulus E of about 11/0.12...
You can't clamp the base.
The way to get pure shear is to put symmetry boundary conditions on the base and left-hand edge. Apply a uniform tension to the top edge and a uniform compression of the same magnitude of the right-hand edge. That is: apply pure shear.
... by the way: the reason for restricting the maximum size of an increment.
If you let ABAQUS increase it by default, and then it's forced to cut-back because it's rather too large when (say) gross yield or softening cuts in, you can end up completely losing the advantage gained from the...
Try relaxing the displacement correction criterion using *CONTROLS ....
Once the load/displacement increments are very small the "noise" in nodal displacement corrections during iterations of an increment can easily be the same size as the nodal displacement increments themselves. This leads to...
This could be involved, but you could try connecting your intended BC nodes to the boundary via (say) simple truss elements. You then vary the elastic stiffness of each of these truss elements via (User defined) field variables.
Initially set the elastic modulus of any particular truss element...
You can easily set up a list of 365 dates in the year in one column of the worksheet; perhaps hidden from the user.
Then, in the cell you wish to choose the date, use Data...Validation. Here Allow...List and in the Source put the range of dates you established in the above paragraph.
I still...
If you run ABAQUS PRE you'll get a .pes (if memory serves me) file in which all the parameters are resolved. You can run that in CAE.
I'm not sure what you are asking in the rest of your question, but you generally need to tune your model against experiments in order to obtain the appropriate...
Aga,
You could try using the UTEMP user subroutine in a model to provide a final temperature distribution and so impose a simulated welding residual stress field. Adjust the UTEMP in order to achieve a reasonable match to your measured profile. However, you'll never get a perfect match; but it...
Hi,
I think perhaps you need to read around the subject a little.
In the meantime I attach an ABAQUS input file which does what you want and attempts to simulate the Round Robin cited in the file using *POROUS...
Hi,
My original example had an AMPLITUDE parameter on *BOUNDARY. You don't actually need this parameter; but if you have it you must ensure that the amplitude is unity during the time step that applies the displacements on the boundary of the model. Of course, if the amplitude is zero you'll get...
