Fracture Resistance of Al2050 Alloy: Experimental Validation of Fracture Mechanics Models

The fracture toughness of a material is a critical factor in structural design and in the material selection process, as it ensures safe and reliable results. This Master’s thesis investigates the effect of thickness on the fracture toughness of Al2050 aluminum- copper alloy, a material widely used in aerospace and automotive industries due to its lightweight and high-strength properties. The study aims to identify the optimal thickness that maximizes fracture resistance while maintaining mechanical performance. Double Edge Notched Tensile (DENT) specimens of varying thicknesses were tested under controlled conditions to evaluate fracture toughness using the Essential Work of Fracture (EWF) methodology. The results reveal a significant thickness dependence, with thinner sheets exhibiting higher fracture toughness due to plane stress dominance, while thicker sheets show re- duced toughness under plane strain conditions. However, while fracture resistance is a key parameter for structural integrity, material selection in engineering applications of- ten involves trade-offs with other mechanical properties, such as tensile strength, fatigue resistance, or weight savings. The findings of this study provide practical guidelines for balancing these competing factors, contributing to the development of lightweight, high-performance structures. This research bridges the gap between material science and industrial applications, offering insights for the design of next-generation materials.