> On Dec 4, 2015, at 5:21 PM, Xujun Zhao <xzha...@gmail.com> wrote:
>
> Yes, this is basically correct. Suppose we know the force density over the
> solid domain, which is set as 1 in the x-direction here. Simply think of it
> as a gravity. This code try to assemble the global force vector Fu =
> \int_{\Omega} \phi*f_density*dx, and Fv = Fw =0.
I don't think the results look unreasonable at all. The value at node "i"
should be proportional to the volume of the elements surrounding node "i", i.e.
the support of basis function phi_i. I'd expect this to vary a bit more for
tets than for hexes. Furthermore it should be smaller for boundary elements
than interior elements, so we should see more "blue"elements on the boundary...
> I expect that no mater what type of elems used, I can get the same nodal
> force distribution over the domain. Now if I use HEX element, the nodal force
> distribution is quite regular, but when TET4 is used, the results don't make
> any sense. See the two figures I attached.
> <HEX.png>
>
>
>
>
> I also tried MeshTools::Generation::build_cube(****, HEX8) and
> build_cube(****, TEX4), the later still gives unreasonable distribution of Fu.
>
>
>
>> On Fri, Dec 4, 2015 at 5:56 PM, John Peterson <jwpeter...@gmail.com> wrote:
>>
>>
>> On Fri, Dec 4, 2015 at 4:28 PM, Xujun Zhao <xzha...@gmail.com> wrote:
>>
>> So, if I understand correctly, you are computing
>>
>> Fu(i) = \int_{\Omega} \phi_i dx
>>
>> i.e. Fu(i) contains the integral of the i'th basis function over the domain?
>>
>> What value are you getting, and what value are you expecting to get?
>>
>> Can you try the same thing on a Mesh generated with:
>>
>>> MeshTools::Generation::build_cube (mesh,
>>> /*nx=*/1, /*ny=*/1, /*nz=*/1,
>>> /*xmin=*/0, /*xmax=*/1.,
>>> /*ymin=*/0, /*ymax=*/1.,
>>> /*zmin=*/0, /*zmax=*/1.,
>>> TET4);
>>
>> just to rule out issues with the Mesh?
>>
>> --
>> John
>
------------------------------------------------------------------------------
Go from Idea to Many App Stores Faster with Intel(R) XDK
Give your users amazing mobile app experiences with Intel(R) XDK.
Use one codebase in this all-in-one HTML5 development environment.
Design, debug & build mobile apps & 2D/3D high-impact games for multiple OSs.
http://pubads.g.doubleclick.net/gampad/clk?id=254741911&iu=/4140
_______________________________________________
Libmesh-users mailing list
Libmesh-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/libmesh-users
