Application of mixed-nanoparticle coating as a novel simple method in generating speckle pattern to study small fields of view by digital image correlation

Digital image correlation (DIC) is a powerful full-field displacement measurement technique that has been used in various studies. The first step in the DIC is to create a random speckle pattern, where the spraying method is usually employed. However, creating an optimal pattern and modification in the spraying method is not convenient. Furthermore, the size of speckles which is not so small in spraying method, limits the minimum size of the field of study. In the present research, a convenient novel technique was introduced and investigated to generate a practical kind of speckle pattern with small speckles for evaluating smaller fields of view using nanoparticles. The pattern was created by spreading a mixture of different black and white nanoparticles. To this end, the black graphene oxide particles were mixed with white nanoparticles of titanium oxide, zirconium oxide and silicon to obtain three mixtures. Displacement tests show that the mixture of graphene and titanium provides the best DIC performance. More granularly, graphene and titanium were mixed at three different ratios to find the optimal combination. Subsequently, the accuracy of the new patterning method was analyzed via tensile testing and the results were compared against those of conventional method with various subset sizes.

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Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).