| Matrix or Vector | Shape Functions | Integration Points | |
|---|---|---|---|
| Stiffness Matrix and Thermal Load Vector | Equation 11–217, Equation 11–218, and Equation 11–219 or, if modified extra shape functions are included (KEYOPT(1) = 0) and element has 8 unique nodes, Equation 11–233, Equation 11–234, and Equation 11–235 | 2 x 2 x 2 if KEYOPT(2) = 0 | |
| Mass and Stress Stiffness Matrices | Equation 11–217, Equation 11–218, and Equation 11–219 | Same as stiffness matrix | |
| Pressure Load Vector | Quad | Equation 11–70 and Equation 11–71 | 2 x 2 |
| Triangle | Equation 11–50 and Equation 11–51 | 3 | |
| Load Type | Distribution |
|---|---|
| Element Temperature | Trilinear thru element |
| Nodal Temperature | Trilinear thru element |
| Pressure | Bilinear across each face |
Reference: Wilson, Taylor et al.
Structures describes the derivation of structural element matrices and load vectors as well as stress evaluations. Uniform reduced integration technique (Flanagan and Belytschko) can be chosen by using KEYOPT(2) = 1.