Hi Robert,
Should I prescribe Dijkl to each vertex like the prestress, or only need to prescribe to each element? Besides, if using strain = pb.evaluate('ev_cauchy_strain.2.Omega(u)', mode='el_avg'), the shear value in strain is sigma_xy or 2*sigma_xy?
Regards Ronghai
在 2014年11月26日星期三UTC+1下午3时14分44秒,Robert Cimrman写道:
On 11/26/2014 02:39 PM, Ronghai Wu wrote:
Hi Robert,
Now I encounter a more complicated case. What if the stiffness tensor is not constant, but a function of eta, as shown in PDF "non-constant elastic tensor.pdf". Is it possible to implement it based on the modified code "Ronghai.py"?
So eta is a known function of position? This can be done by a material parameter given by a user-defined function again [1], just like you do the prestress.
The function would be something like:
def get_d(ts, coors, mode=None, **kwargs): if mode == 'qp': x = coors[:, 0] y = coors[:, 1]
value = ... return {'D' : value}
and in the code, use something like:
d_fun = Function('d_fun', get_d) m = Material('m', function=d_fun)
Also, if you need to work with the elastic tensors, use dw_lin_elastic term instead of dw_lin_elastic_iso.
r. [1] http://sfepy.org/doc-devel/users_guide.html#defining-material-parameters
Regards Ronghai
在 2014年11月15日星期六UTC+1下午7时02分31秒,Robert Cimrman写道:
On 11/14/2014 06:02 PM, Ronghai Wu wrote:
Hi Robert,
I have some explanations of fipy and my idea. Please see attached PDF. If you need more information, please just ask.
That's fine, thanks. I have modified your file and it runs. Note that
you
still need to specify some boundary conditions so that the matrix is not singular.
r.