Darbe Yükü Altýndaki Hibrit Kompozit Plakalara Sýcaklýðýn Etkisi

Bu çalýþmada, karbon-cam elyaf/epoksi (hibrit) kompozitlerin sýcaklýk ve artan darbe enerjisi altýndaki darbe davranýþlarý incelenmiþtir. Bununla ilgili olarak iki tip tabaka dizilim açýsýna sahip, 8 tabakalý hibrit kompozit numunelere -20, 0, 20 ve 40 oC sýcaklýklarýnda, numunelerde delinme meydana gelene kadar darbe enerjisi uygulanmýþtýr. Hibrit kompozitlerin saplanma ve delinme sýnýr deðerlerinin belirlenmesinde, darbe enerjisi ve absorbe edilen enerji arasýndaki iliþkiyi göstermede kullanýlan enerji profili diyagramý kullanýlmýþtýr. Bunun yaný sýra, maksimum temas kuvveti (Fmax), toplam çökme (d) ve maksimum temas süresi (t) gibi önemli darbe karakteristiklerinin sýcaklýk geçiþlerindeki deðiþimleri de sunulmuþtur. Sonuç olarak, cam ve karbon fiberlerin -20 oC’de, diðer sýcaklýklara göre daha çok gevrekleþtiði görülmüþtür. Buna göre her iki tip hibrit kompozit için -20 oC’de meydana gelen delinme sýnýrý diðer sýcaklýklara göre en yüksek deðerde bulunmuþtur.

Temperature Effects on Hybrid Composite Plates Under Impact Loads

In this work, impact responses of carbon-glass fiber/epoxy (hybrid) composites were investigated under various temperatures and increasing impact energies. The increasing impact energies were applied to the specimens at various temperatures as -20, 0, 20 and 40 oC until perforation took place of specimens. Those specimens are composed by two types of fiber orientation with eight laminates hybrid composites. An Energy profiling diagram, used for showing the relationship between impact and absorbed energy, has been used to obtain penetration and perforation thresholds of hybrid composites. Beside those, temperature effects on impact characteristics such as maximum contact force (Fmax), total deflection (d) and maximum contact duration (t) were also presented in figures. Finally, glass and carbon fibers exhibited more brittle characteristics at -20 oC according to other temperatures. So, perforation threshold of each hybrid composites at -20 oC was found higher than other temperatures. Keywords : Hybrid composite