The three-field mixed form based upon the Hu-Washizu principle is introduced to 3 dimensional Free Mesh Method (FMM). We call this new kind of FMM as Mixed 3-D FMM. The Mixed 3-D FMM passed a patch test which is a block under uniform tension. It is then applied to stress analysis of a cantilever beam under bending, and remarkable improvement of accuracy compared to displacement based FMM is shown.
