Tetra1¶

Bases: Element

Four-node linear tetrahedral element.

Notes

Node ordering:

    3
   /|\
  / | \
 /  |  \
0---|---1
 \  |  /
  \ | /
   \|/
    2

`B(xi)` `classmethod` ¶

Evaluate reference-space derivatives of shape functions by autodiff.

Parameters:

xi (Tensor) –

Reference coordinates. Shape: (iso_dim,) or (n_points, iso_dim).

Returns:

Tensor ( Tensor ) –

Derivatives dN/dxi. Shape: (iso_dim, nodes) or (n_points, iso_dim, nodes).

Evaluate reference-space second derivatives of shape functions by autodiff.

Parameters:

xi (Tensor) –

Reference coordinates. Shape: (iso_dim,) or (n_points, iso_dim).

Returns:

Tensor ( Tensor ) –

Second derivatives d²N/dxi_i dxi_j. Shape: (iso_dim, iso_dim, nodes) or (n_points, iso_dim, iso_dim, nodes).