Deflection-Penetration Criterion in defect ridden slanted interfaces: A continuum scale study in 2D Fracture Mechanics and 3D printable models

This paper presents a deeper understanding of the effect of interface orientation and varying defect density within the interface on toughness in 2D media. Our study focuses on a pre-deflected crack that has a majority of its length parallel to the line of symmetry in the horizontal direction, with a small deflected region present in the interface, perpendicular to the line of symmetry. We vary the interface orientation at varying angles with 0 2.5, 5, 7.5, 10, 12.5, 15, 20, 25, 30, 37.5, 45, and 50. For all of the theta , we initially create 10 increments of interface properties, and within each of these combinations, we vary the defect densities ranging from 5 defects to 15 defects. Previous results have shown that higher defect densities in the interface region lead to an overall higher material toughness, while in turn making the interface weaker, allowing for cracks to propagate and deflect with the help of the defects. In this paper, we hope to understand 4 main ideas, (i) How do higher interface angle orientations vs lower angle orientations affect the deflection-penetration criterion? (ii) What is the effect of higher variations vs lower variations of defect densities on the deflection-penetration when faced with differing angles? (iii) How do the Elastic Energy and Stress fields react to changes within the angle of the interface? (iv) Can we recreate the computational results with 3D printable models through tensile testing? Overall, it is quiet clear that in terms of material toughness and stress concentration at the crack tip, the higher angle cases are a clear benefit to the toughness of the material; however, when considering the elastic energy and time needed for failure, the lower angled cases showcase a more preferable case.