Hi Robert,

I have some explanations of fipy and my idea. Please see attached PDF. If you need more information, please just ask.

Regards

Ronghai

在 2014年11月14日星期五UTC+1下午2时54分04秒，Robert Cimrman写道：

I have some explanations of fipy and my idea. Please see attached PDF. If you need more information, please just ask.

Regards

Ronghai

在 2014年11月14日星期五UTC+1下午2时54分04秒，Robert Cimrman写道：

Hi Ronghai,

I have just installed fipy and tried it. Could you explain more the shape of

the prestress array? It is (nx * ny * 4, 3), where nx * ny is the number of

cells (elements of the mesh). Why the factor 4 there? The values seem to be

constant in each cell.

r.

On 11/14/2014 01:03 PM, Ronghai Wu wrote:

> Hi Robert,

>

> I still cannot fix the bug in my codes nor find other better ways. I am

> wondering have you tried my codes found the problem?

>

> Regards

> Ronghai

>

>

> 在 2014年11月11日星期二UTC+1下午4时45分43秒，Robert Cimrman写道：

>>

>> Hi Ronghai,

>>

>> On 11/11/2014 03:03 PM, Ronghai Wu wrote:

>>> Hi Robert,

>>>

>>> Thanks for your reply. I tried your suggestions with the assistance of

>>> http://sfepy.org/doc-devel/users_guide.html#defining- material-parameters

>>> but seems not working.

>>> There are some error massages which I cannot fix. Could you please

>> provide

>>> more help. I additionally have some explanations and questions regarding

>> my

>>> wield codes.

>>> 1. eta is dynamic scalar field, I solve the PDE with respect to eta by

>>> fipy.because I am familiar with fipy. But the elastic equation is

>>> stationary, and eta is as a known input for elastic equation.

>>

>> So eta is then defined in the mesh vertices? Or elsewhere?

>>

>>> 2. I generated my own mesh(as attached) because, a) I am not able to use

>>> gmsh although learned hard, b) I want the mesh numbering or ordering

>> agrees

>>> with fipy mesh. If the generated mesh is applicable for sfepy?

>>

>> Yes, it seems fine. The same mesh (only "transposed" - the numbering of

>> nodes

>> goes y-axis first) can be obtained by:

>>

>> ./script/blockgen.py --2d -s [4,4,4] -o out.mesh

>>

>> that uses "from sfepy.mesh.mesh_generators import gen_block_mesh".

>>

>>> 3. why when printing coors, values are [[0.21132487

>> 0.78867513]........not

>>> real coordinates of mesh vertices?

>>

>> The materials are evaluated in quadrature points for numerical integration

>> and

>> not in the mesh vertices. If your values are in the mesh vertices, you

>> would

>> need to interpolate them to the quadrature points, for example using a

>> field.

>>

>>> 4. I used integral = Integral('i', order=3), but what is the most

>>> appropriate integral for my problem ?

>>

>> Your field is bi-linear, so 3 should be ok.

>>

>>> 5. for stationary problem, if pb.time_update() and pb.update_materials()

>>> are necessary before pb.solve()?

>>

>> Yes, those set up the boundary conditions and materials. A stationary

>> problem

>> is solved as a single step of a quasi-static solver.

>>

>>> My complete codes are shown below. also attached. Thank you.

>>

>> I will look at it.

>>

>> r.

>>

>>

>