Optimierung eines optischen stereoskopischen Verfahrens zur Anwendung an grobkeramischen Baustoffen

The topic of this diploma thesis is the optimisation of the 3D-imaging technique which was used for fractographic investigations of ordinary ceramic materials with different brittleness. The stereoscopic imaging procedure is based on two digital images which show the fracture surface under different tilt angles. From these image-pairs the three dimensional dataset of the fracture surface is calculated by a special software. As the quality of the tilted images highly influences the calculated 3D-dataset, it was necessary to quantify the optimal image quality. Due to the developed optimisation process regarding image quality it was possible to make the calculations reproducible for the investigated refractories. An autocorrelation function was applied to the 3D-dataset for the determination of the fractographic parameter, the lateral correlation length . As shown in this thesis there is a nonlinear correlation between the lateral correlation length and the fracture mechanical property the characteristic length l_ch. The fractographic investigations showed that the lateral correlation length is an appropriate parameter for the characterisation of the investigated refractories.