Monitoring of the composite materials destruction kinetics using acoustic-emission diagnostics

The structural-phenomenological concept (SPC) and model of the evolution of destruction of a composite material are considered, connecting its load-bearing capacity with the kinetics of redistribution of the weight content of micro, meso and macroscale damage during loading. By monitoring changes in the values of partial accumulation of damage in the structure of the material at different scale levels in the loading mode, and comparing them with threshold values, it is possible to control the actual state of the load-bearing capacity of the product. The correspondence between the surface of micro, meso, macro-destruction of structural bonds of a structural material and the energy parameters of the acoustic emission pulses recorded in this case, forming in the field of descriptors of relative energy ( E i ) and maximum amplitude ( u m ), clusters of the lower (L), middle (M), and upper (H) levels with boundaries: E i < 85 dB, u m < 55 dB; E i = 85 – 115 dB, u m = 55 – 80 dB; E i > 115 dB, u m > 80 dB. An algorithm and software (software) have been developed that controls the dynamics of the redistribution of parameters of partial activity ( Ń i ) and weight content ( W i ) of location pulses in energy clusters characterizing the kinetics of micro-, meso- and macro-damage «in situ» of violation of the structural bonds of a product under loading mode. By comparing the current values of the most informative parameters W L and W M , with their threshold values [ W L ] and [ W M ], corresponding to the state of the product when the material is destroyed, we get the opportunity to control the actual level of the load-bearing capacity of the structure. The developed concept, algorithm and software were used to evaluate the load-bearing capacity of the panel mesh structure during compression tests under loading conditions.