Some experimental observations of crack-tip mechanics with displacement data
Journal Title: Frattura ed Integrità Strutturale - Year 2015, Vol 9, Issue 33
Abstract
In the past two decades, crack-tip mechanics has been increasingly studied with full-field techniques. Within these techniques, Digital Image Correlation (DIC) has been most widely used due to its many advantages, to extract important crack-tip information, including Stress Intensity Factor (SIF), Crack Opening Displacement, J-integral, T-stress, closure level, plastic zone size, etc. However, little information is given in the literature about the experimental setup that provides best estimations for the different parameters. The current work aims at understanding how the experimental conditions used in DIC influence the crack-tip information extracted experimentally. The influence of parameters such as magnification factor, size of the images, position of the images with respect the crack-tip and size of the subset used in the correlation is studied. The influence is studied in terms of SIF and T-stress by using Williams’ model. The concept of determination of the K-dominance zone from experimental data has also explored. In this regard, cyclic loading on a fatigue crack in a compact tension (CT) specimen, made of aluminium 2024-T351 alloy, has been applied and the surface deformation ahead of the crack tip has been examined. The comparison between theoretical and experimental values of KI showed that the effect of subset size on the measured KI is negligible compared to the effect of size of the image.
Authors and Affiliations
M. Mokhtari, P. Lopez-Crespo, B. Moreno
Keywords
Related Articles
- EP ID EP122210
- DOI 10.3221/IGF-ESIS.33.18
- Views 58
- Downloads 0
Fatigue crack growth behavior of Inconel 718 produced by selective laser melting
Additive layer manufacturing has recently gained a lot of interest due to the feasibility of producing metallic components directly from a computer-aided design file of the part. Selective laser melting, one of th...
Simulation of accelerated strip cooling on the hot rolling mill run-out roller table
A mathematical model of the thermal state of the metal in the run-out roller table continuous wide hot strip mill. The mathematical model takes into account heat generation due to the polymorphic γ → α transforma...
Short review: Potential impact of delamination cracks on fracture toughness of structural materials
The current energy policy envisages extended lifetime for the current nuclear power plants (GEN II NPP). This policy imposes a large research effort to understand the ageing of power plant components. In this...
Experimental investigation of effect of specimen thickness on fracture toughness of Al-TiC composites
In this paper, the macro and micro-mechanical fracture behavior was studied for aluminum (Al6061) alloy matrix, reinforced with various proportions of TiC particles such as 3wt%, 5wt% and 7wt%. The Al6061-TiC...
A consistency assessment of coupled cohesive zonemodels for mixed-mode debonding problems
Due to their simplicity, cohesive zone models (CZMs) are very attractive to describe mixed-modefailure and debonding processes of materials and interfaces. Although a large number of coupled CZMs havebeen proposed,...