14. starptautiskā konference 2012 - Latvijas Jūras akadēmija

Proceedings of 14th International conference „Maritime Transport and Infrastructure - 2012”N ae3503002502001501005000a20 40 60 80 Time, secbFig. 3. The summarize (Nae) of acoustic impulses AE vs. Time at heating and cooling:a - specimens with defects, b – specimen free of defectsWe can see, that during the heating the specimen with defects (left side of Fig.3, a) theimpulses of acoustic emission begin to intense summarise till finishing of thermo loading (+70°C).And after the heat treatment (the right side of Fig.3) we also see some growth of summarising of AEimpulses, but with the less intensity. In opposite, the free of defects specimen (Fig.3, b) practically donot reproduce the AE impulses during the whole time of experiment of heat loading.Most likely during heating of the defective zone, not making single integral formation yet,occurs further stratification of composite components, as causes the accelerated generating of AEimpulses, not fading at natural cooling. In the second case (a faultless specimen), the design elementpractically behaves as a single formation, which is not reacting to thermal impact.Test 2 As other object of research has been chosen full scale aileron, which also was exposedto heating to +70ºC. However, due to big size of the new research object versus previouslyinvestigated two specimens heating zones were chosen near the defective zone in one case - this zonewas determinate as defective by an impedance method (natural peeling was revealed). In another case,as other place of heating also to +70º has been chosen the faultless zone. Also an impedance methoddetects this free of defect zone (Fig.4).Fig. 4. The arrangement scheme on full-scale aileron:1- The Acoustic Emission piezoelectric gauge,2 - heating zones near the defect zone, 3 faultless zone.The plan of experiment was the same as for the previous Test 1: heating impact till +70 ºC inthe zone 2 and 3 (Fig.4) and natural cooling in premise till +18 ºC. The summarising of acousticemission impulses has the same mode as in the previous case with two specimens in Test 1. More thanthat, as the settings of the equipment of the experiment do not changing, we see a little less total sumof the acoustic emission impulses (Fig.5).48