DEFECT CONTROL DURING TESTING OF ACM CARBON FIBER SAMPLES

Static tests of eight samples from the domestic carbon fiber ACM 102-C130UD with geometric dimensions of 100×350×2.7 mm were performed. The samples were reduced in width in the central part to 60 mm, where two side cuts with a length of 4 mm each were located. Acoustic emission method, acoustoelasticity, strain gauge and fractography were used to record information about the destruction of carbon fiber material in the cut zone. The acoustic emission method was used to locate sources in the area of the voltage concentrator in real time. Using an ultrasound flaw detector with a phased array converter, practically no defects were detected, since their dimensions, as shown by fractography, are significantly less than its resolution. The analysis of the fractography results made it possible to determine the restructuring of the AFM carbon fiber structure during static stretching of samples and its effect on the main informative parameters of acoustic emission signals (location, median frequency, energy parameter MARSE).