Hi
I try to simulate a metal forming process with abaqus/explicit.
I use of mass scaling method with 1E8 factor. During of solution the kinematic energy is less than 10% of total energy.
Because of large deformation I should use of ALE method and C3D8R element.
The frequency of ALE is 3 and Remeshing sweep per increment is 3 and create an adaptive mesh control for improve aspect ratio and other option is on default.
Because of type of element the hourglass mode happens. I activate hourglass mode and try all of type but the hourglass mode again happens.
Please help me. Thanks
Errors:
The elements in element set ErrElemZeroALEMass-Step1 have zero or negative mass.
The elements contained in element set ErrElemExcessDistortion-Step1 have distorted excessively.
Hi,
which kind of process are you simulating? My PhD thesis was about wire drawing processes, and I used ABAQUS standard. In any case, it seems you elements are too low stiff.. Have you tried elements fully integrated?
Another possible problem is the mass scaling. The energies you compared are TOTAL energies. Locally, i.e. at the level of a single element (especially for elements that are very much deformed), you can have "peaks" of kinematic energies that create numerical problems.
I see from your image that your problems are in an external surface. If you are interested to a solution far away from these elements, you can try to add an equation on your model, in order to force the nodes of this face to remain plane during the deformation, in order to distribute the energies on a larger number of nodes...
Good luck!
A.
@Deepak Kumar i do it. the time of simulation increased very much but did not work and after 2 second simulation stop with same error
hi Andrea Panteghini
its ECAP. yes i use fully integrated element but have same error after more CPU time for small move punch.
yes, it is happened in surface always. i active adaptive mesh control and define a surface on my billet for create sliding boundary region by abaqus, but i don not know how can i have a constrain that make nodes remain on surface billet?
should i define a subroutine?
i active adaptive mesh constrain.can i constrain mesh on billet surface in underlying material mode or by limited two DOF of mesh? which on DOF?
No, *Equation is a constrain that you can define directly in CAE, in interaction module.
You have to define two sets: the first one containing only one node (for example, you can use a vertex), the other one containing all the nodes with the exception of the first one, and then you can write an equation imposing that this surface must remain plane.
thank you very much. i should try it. i fill the set column with that set you said but i do not know how fill the DOF column?
and my billet have cylindrical surface. is it possible remain flat?
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