Twenty-node brick element (C3D20)

The C3D20 element is a general purpose quadratic brick element (3x3x3 integration points). The shape functions can be found in [41]. The node numbering follows the convention of Figure 60 and the integration scheme is given in Figure 61.

Figure 60: 20-node brick element

Figure 61: 3x3x3 integration point scheme in hexahedral elements

This is an excellent element for linear elastic calculations. Due to the location of the integration points, stress concentrations at the surface of a structure are well captured. However, for nonlinear calculations the elements exhibits the same disadvantages as the C3D8 element, albeit to a much lesser extent: