Temperature and test specimen thickness (TST) effect on tensile and fracture behavior of AA2050-T84 alloy

Abstract

AA2050-T84 is a third-generation Al-Li alloy used for primary structures of the modern transport aircraft wing. Temperature variation is common during flights, and the effect of temperature on the damage tolerance behavior of Al-Li alloys is significant. In the present work, the effect of temperature on tensile and fracture toughness of the AA2050-T84 alloy was tested experimentally. Further, the effect of Test Specimen Thickness (TST) on crack behavior is studied numerically using constraints variation. The Compact Tension (C(T)) specimen was used for linear elastic fracture analysis with variation in thickness to width ratio (B/W) as 0.1, 0.5, and 1. T11 and T33 constraint parameters were used to measure the effect of TST at −20 °C, 24 °C, and 200 °C. Increase in specimen thickness for constant stress intensity factor (KI) resulted in the decrease of T11. However, the T33 increased with an increase in specimen thickness for all temperatures considered. At −20 °C and 24 °C temperatures, the T11 variation was almost identical at all thicknesses. However, a decrease in T11 around 8% was witnessed at 200 °C compared to room temperature. The temperature effect on the T33 variation was steady and marginal. The temperature and TST effect on AA2050-T84 alloy was significant, and the present investigation results are crucial for aircraft design engineers.