Hello to everybody,
I am trying to simulate the orthogonal cutting of carbon fiber reinforced polymer composite using Abaqus v6.13 software. In my 2D model, Fiber and Matrix are represented as different phases. Damage models for fiber and matrix are implemented.
I have tried to use two different approaches:
- Partitioning a rectangle and giving to each partition different material models. In this case the drawback is that it is not possible to set the contact between fiber and matrix, so I gave up with this approach.
- Creating each phase separately and linking them using Tie Constraint and setting the contacts pair among each phase.
I started with a small model, only two fibers and tree matrix phases to check if everything is ok.
Using the first approach the analysis is completed without problems. Instead, using the second one I always get the following errors:
***ERROR: There are a total of 2 excessively distorted elements
***ERROR: The ratio of deformation speed to wave speed exceeds 1.0000 in at least one element. This usually indicates an error with the model definition. Additional diagnostic information may be found in the message file.
I run different models in order to understand if these errors are due to material model, boundary conditions, cutting speed (8 mm/s) or whatever.
Recently I have noticed that my model can run without error if I avoid to put the contact, i.e. only with tie constraint. So, these errors could be due to a contact definition.
When I run the job, I usually get the following warning messages:
***WARNING: Some elements underlying deformable surface ASSEMBLY_F9L are
referenced by a *CONTACT PAIR option. In addition these elements have material properties that allow the elements to fail. For elements that can fail, contact should be defined using the *CONTACT option. A element set named "WarnElemFailElemInContact" containing these elements is created to help the user locate the elements.
***WARNING: Each of the nodes listed below participates in a kinematic
constraint as well as being part of a kinematic contact surface definition. Nodes that participate in a kinematic constraint definition should not be used in a kinematic contact surface definition. If a degree-of-freedom participates in both types of constraints, the kinematic contact constraint will most often override the kinematic constraint. Abaqus/Explicit will not prevent the user from defining these conditions, but the results cannot be guaranteed. It is suggested that the penalty contact algorithm be used.
I used both Kinematic and Penalty contact, but I don’t know how to fix these warnings.
Could my problem be related to these warnings?
Any suggestion will be appreciated.
Thank you in advance for your reply.