This paper numerically compares the axial stiffness and local stress of three BCC lattice specimens under compression. The intact REF model is compared with the INT and SIDE models, which have one missing internal strut and one missing strut near a lateral surface, respectively. All variants use the same linear elastic structural steel model, end plates, and prescribed axial displacement of 0.01 mm. Calculations were performed using nominal element sizes of 0.5 and 0.4 mm. Compared with REF, axial stiffness decreased by approximately 0.593% for INT and 0.276 – 0.282% for SIDE. The stiffness ranking remained unchanged for both meshes. The maximum local stress on the monitored retained strut was more sensitive to mesh size. For INT, the sign of the difference relative to REF also changed. The results demonstrate the need to evaluate the stiffness of the entire specimen and stress in the selected region separately.
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