Figure 6

Node locations on t-faces and t-edges for linear (left), quadratic (middle), and cubic (right) mapping. The first order surface element contains three nodes coincident with the vertices. The second order surface element includes all nodes from the first order elements plus the edge midpoints for the total of 6 nodes. The third order surface element includes all nodes from the first order elements plus the points at the thirds of each edge and the centroid, 10 nodes in total. The nodes of line elements representing t-edges are shown below each surface element