A study of the evolution of crack tip plasticity along a crack front. (December 2018)

• Record Type: Journal Article
• Authors: Lopez-Crespo, P.; Camas, D.; Antunes, F.V.; Yates, J.R.
• Is Part Of: Theoretical and applied fracture mechanics. Volume 98(2018)
• Page Start: 59
• Page End: 66
• Publication Date: 2018-12
• Subjects: Fracture mechanics -- Periodicals; 620.1126
• DOI: 10.1016/j.tafmec.2018.09.012
• Languages: English
• ISSNs: 0167-8442

Abstract

Highlights: An ultrafine finite element model of a cracked component allows visualising the plastic zone in great detail. A bi-dimensional equivalent plastic zone shape is derived from the three-dimensional yielded volume. A correction factor for the theoretical plastic zone at plane stress conditions is determined. Its evolution with the specimen thickness is obtained. The numerical model has been validated with full-field digital image correlation experiments. Abstract: In this work, we present a detailed numerical analysis of the evolution of the plastic zone through the thickness of compact tension aluminium alloy specimens. An ultra-fine non-linear finite element model was used to characterise with great detail the size and shape of the plastic zone for different thicknesses. The numerical plastic zone was compared in size and shape with the plane strain and plane stress Dugdale plastic zones. In general, the maximum plastic zone was found to be in the interior but closer to the surface than to the mid plane. We also propose an equivalent bi-dimensional plastic zone for converting the complex 3D distribution into a 2D plastic zone. Finally, the numerical results were validated using experimental displacement data measured optically from the surface of the specimen.