TESTING OF CFRP SPECIMENS WITH IMPACT DAMAGE USING THE ACOUSTIC EMISSION METHOD AND TENSOMETRY

Abstract

Samples of carbon fiber T 700 were researched. They were subjected to impact damage, after which they were loaded with a static load until failure. Registration of defects was carried out using the method of acoustic emission (AE) and tensometry. In the process of loading the samples, the deformation and load were determined, at which the AE signals were located. An antenna consisting of piezoelectric acoustic emission transducers (PAE) and fiber optic sensors (FOS) was used to monitor defects. When the load changed from 80 to 100 kN, a jump in mechanical stresses was observed in the samples from 338 to 432 MPa, registered by the certified microprocessor-based high-speed tensometic system “Dynamics-3”. In this case, the average amplitude of the AE signals significantly decreased, starting from the load P = 80 kN, after which it increased at the load P = 110 kN. For sensors PAE 3 and VOD 2, located on the opposite side of the sample, where impact damage was absent, these changes in the amplitudes of the AE signals were less pronounced.