Notch Shape Influence on Damage Evolution of Al/CFRP Laminates Under Tensile Loading: Experimental and Numerical Analysis

The present study investigates the influence of different notch shapes on the mechanical response and mechanism of damage evolution during tensile test of carbon fiber aluminum laminate (Carall) fabricated in the three different configurations Al/0 degrees/Al/0 degrees/Al, Al/0 degrees/Al/90 degrees/Al, and Al/90 degrees/Al/90 degrees/Al (designated as Carall 1, Carall 2 and Carall 3 respectively) through experiments and finite element (FE) simulations. The FE simulation results shows a close agreement with ultimate net notch strength obtained from tensile test along with the longitudinal strain field near the notch recorded from digital image correlation method. Net notch stress-vs-strain plot are distinguished in two regions wherein the slopes of both regions depend on the configuration and notch shape in the laminate. The elliptical cavity with major axis in transverse to loading direction exhibits minimum net notch strength, maximum localized strain, and maximum notch sensitivity for Carall laminate of all the three configurations due to the maximum curvature of the cavity. The fractographic observations by field emission scanning electron microscope confirm the occurrences of damage behavior in terms of location, path, and critical damage mode similar to the FE, prediction. Matrix failure, delamination, fiber failure followed by ductile damage are observed for Carall 1 and Carall 2 whereas, matrix failure and ductile damage are the major failure mode for Carall 3 laminates.