Analysis of porosity-induced stress intensity factors for the evaluation of inline-computer tomography scans of cast parts

Abstract

A major role in the process of quality assurance of cast parts is the analysis of porosities. In this paper, a method providing an evaluation technique of the available 3D data offered by the new computed tomography (CT) technology is developed, describing how the material’s strength at the location of the porosity gets attenuated. The steps in achieving this goal are as follows: First, the multitude of tensile testing results of porosity-afflicted samples at hand is to be studied giving rise for quantitative descriptions of the main influential factors of the material’s degradation, like the porosity shape, the position, the minimum radius, the distance to surface, etc. Then, the second step is to build up a numerical testing setup, facilitating to modify these parameters independently of each other utilizing characteristic porosity geometries. After validation of this model in regard of the known experimental results, at third, a design of experiments (DOE) has to be performed on it revealing the main dependencies of the shape’s properties on the stress concentration factors. Eventually, the applied approach is evaluated for prediction of fatigue life and fracture plane position of porous material.