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. 2018 Nov 16;11(11):2306.
doi: 10.3390/ma11112306.

Fracture Statistics for Inorganically-Bound Core Materials

Philipp Lechner  1 , Jens Stahl  2 , Florian Ettemeyer  3 , Benjamin Himmel  4 , Bianca Tananau-Blumenschein  5 , Wolfram Volk  6   7
Affiliations

Fracture Statistics for Inorganically-Bound Core Materials

Philipp Lechner et al. Materials (Basel). .

Abstract

In this article, we study the fracture characteristics of inorganically-bound foundry cores. It will be shown that the fracture stress of inorganic cores follows Weibull's strength distribution function for brittle materials. Using three-point and four-point-bending experiments, the volume dependence of the bending fracture stress is analyzed and a Weibull model fitted. Furthermore, the fracture stress of arbitrary bending experiments can be calculated based on the Weibull parameters found.

Keywords: Weibull; four-point-bending; fracture strength; inorganic sand core materials; three-point-bending; water-glass.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Test setup for the 4PB (a) and 3PB (b) experiments.
Figure 2
Figure 2
Quarter model of the beam for 4PB 75.5 mm and 3PB.
Figure 3
Figure 3
Overview of inorganically-bound quartz sand with broken binder bridges (a) and a broken binder bridge with signs of brittle failure (b).
Figure 4
Figure 4
Strength probability distribution with Gaussian and Weibullian fit.
Figure 5
Figure 5
Fracture probability for a 3PB and a 4PB (load distance 63 mm) dataset with different effective volumes.
Figure 6
Figure 6
Specimen Type A: prediction of fracture probability from 4PB (75.5 mm) to 3PB.
Figure 7
Figure 7
Specimen Type A: prediction of fracture probability from 4PB (28.8 mm) to 3PB.
Figure 8
Figure 8
Specimen Type A: prediction of fracture probability from 4PB (75.5 mm) to 4PB (28.8 mm).
Figure 9
Figure 9
Specimen Type B: prediction of fracture probability from 4PB (63 mm) to 3PB.
Figure 10
Figure 10
The FEM results show the stress in the x-direction of 3PB (top) and 4PB 75.5 mm (bottom), which were used for the calculation of the effective volume.
Figure 11
Figure 11
FEM results show the stress in the x-direction of 4PB 75.5 mm with a refined scale (top) and the stress distribution along the lower surface of the bar (bottom).
Figure 12
Figure 12
Fracture locations for a 4PB experiment with a 75.5-mm load distance (a) and the broken bending beams (b).
Figure 13
Figure 13
Specimen Type A: Prediction of fracture probability from 4PB (75.5 mm) to 3PB based on FEM analysis.
Figure 14
Figure 14
Specimen Type A: Prediction of fracture probability from 4PB (28.8 mm) to 3PB based on FEM analysis.
See this image and copyright information in PMC

References

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