A method for determining characteristics of a crack detected in a material, comprising: determining initial mechanical loads applied to the material, applying a plurality of crack-opening mechanical loads to the material, each opening mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each opening mechanical load, applying a plurality of crack-closing mechanical loads to the material, each closing mechanical load being a linear combination of the initial mechanical loads, and measuring the relative displacement of the first point with respect to the second point induced by each closing mechanical load, and estimating the direction of the crack as a function of the amplitude of each opening and closing mechanical load applied to the material and of the measured relative displacements.