PSI - Issue 28

2138 Stylianos Anastopoulos et al. / Procedia Structural Integrity 28 (2020) 2132–2141 S. Anastopoulos et al. / Structural Integrity Procedia 00 (2019) 000–000 The flow direction orientation term contains most of the quantitative information about the microstructure and is most sensitive to flow, processing and material changes. (ANSYS documentation) In Fig. 8 are shown examples of ANSA model representation for the random orientation tensor case.

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Fig. 8 Orientation Tensor: (a) model representation and (b) model zoomed-in on individual inclusions

2.6. Pre-cracked model An example of the pre-cracked model geometry, boundaries shown in blue; loading in yellow, is shown in the picture below in Fig. 9. A preexisting crack mouth opening was modeled.

Fig. 9 Specimen Geometry, loading and boundaries

3. Experimental data 3.1. Experimental data

Experiments of specimens subjected to three point bending flexural tests were provided by the long year research of Prof. Metaxa et al. (2010, 2010, 2011, and 2012). The specimens were of a cement paste matrix with multi walled carbon nanotube (MWCNT) inclusions of various volume percentages, between 6 and 20 ‰. Preparation of cement paste and mechanical testing (Fig. 10) can be assessed in the above articles for more details. The MWCNTs were either all a short or of a long type shape. This paper focuses on the short type inclusions. The preloaded specimens were notched in the middle.

Fig. 10 Three-point bending flexural test fixture