Structural–Phenomenological Concept and Acoustic-Emission Diagnostics of Composite Stringers under Three-Point Bending Conditions

The essence of the proposed methodology for monitoring the kinetics of damage to a deformed material is to establish a correspondence between micro-, meso-, and macrodamage, and the acoustic emission pulses generated in this case. During the loading process of a product, the recorded pulses are divided into pulse flows of low (H), middle (C), and high (B) energy levels, corresponding to the energy of destruction of structural bonds. By calculating the current values of the partial content of acoustic emission pulses in the H, C, and B clusters generated by micro-, meso-, and macrodamage, and comparing them with the threshold ones established during destruction, the load-bearing capacity current level of a product during loading is determined. Application of the developed methodology for identifying zones of developing damage and assessing the load-bearing capacity of the current state of stringers under loading conditions during interlayer shear tests is considered.