<p>As a result of studying the mechanical behavior of knitted 3D-carbon fiber specimens using standard methods (curved beam bending, shear in the stacking plane), it was possible to formulae the concept of the critical value of the cumulative acoustic emission energy for a given structure and type of loading as an acoustic analogue of the ultimate strength (load-carrying capacity). An algorithm for analyzing acoustic emission signals was proposed to determine the critical value of cumulative energy, which is the acoustic equivalent of the ultimate strength (load-carrying capacity) of materials from the beginning of loading to the expected extremum in the case of ambiguous diagrams. The algorithm for determining the critical value of cumulative acoustic emission energy is based on approximating the time-dependent energy parameter with a polynomial function and analyzing its extremums.</p>