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Surface load [ Reply ]
By: Forge Admin on 2018-10-01 15:25
[forum:886]
Question : I am using 'Fsurf' for applying the pressure load of -10N in downward direction on structures. However, after finishing calculating and obtaining the load vector, I calculate the total load by summing the loads. The result is 10N (not -10N).

Therefore, my question is if I want to apply load in downward direction, should I put positive or negative value in SDT? May you help to check my codes below if it is correct?

My codes are as follows:

global FEnode
global FEelt
FEnode = [1 0 0 0 0 0 0; 2 0 0 0 1 0 0;3 0 0 0 0 1 0; 4 0 0 0 0.5 0 0; ...
5 0 0 0 0.5 0.5 0; 6 0 0 0 0 0.5 0;7 0 0 0 -1 0 0;8 0 0 0 -0.5 0.5 0;...
9 0 0 0 -0.5 0 0];
FEelt = [];
model = struct('Node',FEnode, ...
'Elt',feutil('addelt','tria6',[1:6 1 1;1 3 7 6 8 9 1 1]), ...
'pl',[1 fe_mat('m_elastic','SI',1) 210e9 0.3 7850], ...
'il',[1 fe_mat('p_solid','SI',1) 0 -3]);
model = feutil('Extrude 4 0 0 .25',model);
model=fe_case(model,'FixDof','clamped dofs','z==0');
[mo0,Case]=fe_case('assemble -MatDes 2 1 -NoT -SE',model);
data=struct('sel','z==1','eltsel','withnode {z>=1}','def',-10,'DOF',.19);
model=fe_case(model,'Fsurf','Surface load',data);
Load = fe_load(model);
feplot(model,Load);
Total_load = sum(Load.def);


Answer : I refined the fe_load documentation by saying

Note that pressure is DOF {\tt .19} and generates a load opposite to the outgoing surface normal.

In your example, the outgoing normal of selected elements is going up, so to have a downward load you need to use a positive pressure.






Thermal analysis in SDT [ Reply ]
By: Balmes on 2009-07-15 06:54
[forum:19]

> Some customer request us to read ANSYS thermal analysis data.
> Is it possible?

ANS2SDT has multiphysic read capabilities. It should already read thermal data without problem.

> Of course currently SDT dose not have such
> feature, but do you have plan to do that?

oncerning thermal Analysis in SDT it has been available for a while, but I realize with your mail that we did not put the associated demos/documentation in the distribution. You can see the associated demos at

http://support.sdtools.com/gf/project/openfem/scmsvn/?action=browse&path=%2Ftrunk%2Fdemos%2F

we will make sure to include them in the upcoming SDT 6.2 documentation.