The C3D20 element is a general purpose quadratic brick element (3x3x3 integration points). The shape functions can be found in [42]. The node numbering follows the convention of Figure and the integration scheme is given in Figure .
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: