[ff3d-users] [ Solve an elasticity problem ]

[hackervalley]

Hello All,

First thank for ff3d.

Now , I would solve an elasticity problem on a cube.

Here are my data :

cube.pov

box
{
<0,0,0>,
<20,20,20>
pigment { color rgb <1,0,0>}
}
plane
{
<0,1,0>, 0
pigment { color rgb <0,1,0>}
}
plane
{
<0,1,0>, 20
pigment { color rgb <0,0,1>}
}

elasticity.txt

/* Elasticity */

/* Young Module */
double E = 210000;
/* Poisson value */
double poisson = 0.3;
double mu = E/(2*(1+poisson));


vector n = (200,200,200);
vertex a = (0,0,0);
vertex b = (20,20,20);

mesh M = structured(n,a,b);
scene S = pov("cube.pov");
domain O = domain(S,inside(<1,0,0>));

/* st stress d deplacement */
/* PFD Navier */
solve(st,d) in O by M
{
pde(st)
div(st) = 0;
s = E/(1+poisson)*(td+poisson/(1-2*poisson)* Trace(td)*mu);
td = 1/2*(grad(d)+grad(Transpose(d)));
st = 100 on <0,0,1>;
pde(d)
E/(2*(1+poisson))*div(grad(d))+E/(2*(1+poisson)*(1-2*poisson))*grad(div(d)) 
= 0;
d = 0 on <0,1,0>;
}

save(medit,"st.mesh",st,M,unix);
save(medit,"d.mesh",d,M,unix);


I don't see how compute Trace(td) and Transpose(d).
I would also notice as save in medit , I have also wrong data for medit

-- Medit,  Release 2.2 (Sept., 2002)
    Copyright (C) INRIA, 1999-2002.
    compiled: Tue Jan 21 18:34:49 CET 2003.

Loading data file(s)
 Reading u.mesh
 ## ERR 0003, inmesh, WRONG DATA TYPE.
 Input seconds:     0.00

Total running seconds:  0.01
Thank you for using Medit. Bye.

Here my data .

vector n = (10,10,10);
vertex a = (0,0,0);
vertex b = (2,2,2);
mesh M =structured(n,a,b);
scene S = pov("void.pov");
domain O = domain(S);

solve(u) in O by M
{
pde(u)
-div(grad(u)) = 1;
u =0 on M;
};

save(medit,"u.mesh",u,M,unix);

I hope you can help me .

Thank you.