Re: [Libmesh-users] Rigid plates as BCs

[Renato P. <re...@gm...>]

Adding the mailing list in distribution...

On Wed, Feb 20, 2019 at 6:03 PM Renato Poli <re...@gm...> wrote:

> Thanks.
>
> Do you see a better way to do?
> I can see that Abaqus uses an extra node to tie all dofs together.
> I need the DOFs to be identical.
> That means eliminating lines in the matrix so that the displacements are
> identical to each other.
>
> Renato
>
> On Wed, Feb 20, 2019 at 5:53 PM John Peterson <jwp...@gm...>
> wrote:
>
>> On Wed, Feb 20, 2019 at 2:43 PM Renato Poli <re...@gm...> wrote:
>>
>>> Hi all,
>>>
>>> Just refreshing this one, because I am sort of stuck in inserting a
>>> "rigid"
>>> BCs.
>>> It seems simple, but I cannot make it work.
>>>
>>
>> Hi,
>>
>> From your error message, it sounds like you are introducing a coupling
>> (through the constraint) between two dofs which would otherwise not be
>> coupled, and this causes a new nonzero to be inserted into the system
>> matrix after preallocation. You may be able to work around this issue by
>> augmenting the sparsity pattern using a GhostingFunctor, similar to what is
>> done in miscellaneous/miscellaneous_ex9/augment_sparsity_on_interface.h.
>>
>> --
>> John
>>
>>