  We have developed a simple model for the study of a cubic to tetragonal
martensitic transition, under athermal conditions, in systems with a certain
amount of disorder. We have performed numerical simulations that allow for a
statistical study of the dynamics of the transition when the system is driven
from the high-temperature cubic phase to the low-temperature degenerate
tetragonal phase. Our goal is to reveal the existence of kinetic constraints
that arise from competition between the equivalent variants of the martensitic
phase, and which prevent the system from reaching optimal final
microstructures.
