Determination of the criteria of controlling the state of stress in composite materials during steplike loading

Criteria for controlling the state of stress in composite materials based on epoxy resin filled with sand are determined using the phenomenon of mechanoelectrical conversion in dielectric materials. The principle of synchronous detection is applied to analyze the experimental results. Reference signals are taken to be the mechanoelectrical conversion pulse at a zero load and the acoustic pulse emitted by a piezoelectric transducer. It is shown that the elimination of low-informative time intervals from responses leads to a quasi-linear dependence of the chosen control criteria on the pressure applied to a sample and to an increase in the sensitivity of the criteria to the applied load.