Bonjour,
Thank you for you reply.
I calculate the jabobian matrix using J=[(x_node(2)-x_node(1))/2 0; 0
(y_node(4)-y_node(1))/2]. This is a special case for rectangle element (not
applicable for general quadrilateral element).
If I calculate like this, all the terms will be zeros when the
Hi Nan, I agree with Jeremy try to see if you are multiplying wrong the
shape functions' gradients (for example the 2nd shape function gradient
with the coordinates of the 3rd vertex). If you are using a close code the
only solution that is in my mind is to do a program to reedit the .msh as
you
AFAI, rotations should not give rise to singularities in the jacobian.
In fact, these orderings are equivalents as you state, they give the
same normals following the "right-hand rule".
On Mon, 2016-11-14 at 11:04 +0100, Nan Li wrote:
> Hello everyone,
>
>
> I met a problem about the node
