In this microstructural simulation of the mechanical behavior of FeMn-based shape memory alloy samples at mechanical cycling the threefold symmetry of the close-packed planes {111} of the austenitic fcc phase and basic planes {0001} of the martensitic hcp structure and the multi-variance of the reverse martensitic transformation are taken into account. Damage accumulation and resulting fatigue fracture are described in the terms of the internal variables associated with a damage variable and the densities of the oriented and scattered deformation defects. A deformation-and-stress criterion of fracture is proposed. It takes into consideration the effect of hydrostatic pressure, deformation defects and material damage. It is shown that the approach is suitable for describing the fatigue fracture of iron-based shape memory alloys at cyclic mechanical loading.