PSI - Issue 46

A.S. Voznesenskii et al. / Procedia Structural Integrity 46 (2023) 155–161 A.S. Voznesenskii et al. / Structural Integrity Procedia 00 (2019) 000–000

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specimens of this group, the interlayers of carbonaceous clays had small thicknesses, which affected the KC to a lesser extent than in the specimen GG-1. The K C of specimens with a V-shaped concentrator in the region of the interface between flint and gypsum of the GK group are in the interval between the GG and KK groups. This indicates a smooth transition from flint to gypsum in the area of their interface. The presence of carbonaceous interlayers in the GUK group leads to a decrease in crack resistance compared to GK and an approach to K C , which is characteristic of gypsum. 5. Conclusions 1. The test investigated the fracture toughness of the interfaces between rocks comprising gypsum stone. It consists of gypsum, flint, and interlayers of carbonaceous clays. The fracture toughness coefficient K C varies from 0.832 to 1.089 for gypsum and from 2.447 to 2.461 for flint. FT in interfaces between these ones have intermediate values. 2. The results obtained allow us to conclude that there is a smooth transition of the components and the change in the fracture toughness coefficient K C along the specimen axis in the region of the interface between gypsum and flint. 3. Interlayers of carbonaceous clays influence the K C of rocks and the interfaces between them. The degree of this influence depends on the thickness of the interlayers and their location relative to the notch. Interlayers less than 0.1 mm thick do not significantly affect K C , especially if they intersect the notch plane at an angle. Acknowledgements This work was carried out with the financial support of the RFBR grant (project No. 20-05-00341). The authors are grateful to O. V. Savitsky, Chief Engineer of the "Knauf Gips Novomoskovsk" mine, and geologist M. M. Shashkov for advice and assistance in the selection of rock specimens. V. B. Ivanov, P. I. Dubinin, and O. V. Stoyko are also acknowledged for help in making the experimental setup and preparing the specimens for testing. References Benmokrane, B., Mohamed, H.M., Ali, A.H., 2018. Service-life-prediction and field application of glass fiber-reinforced polymer tubular and solid bolts based on laboratory physical and mechanical assessment. J. Compos. Mater. 52, 3309–3323. https://doi.org/10.1177/0021998318764806 Beygi, R., Carbas, R.J.., Barbosa, A.Q., Marques, E.A.S., da Silva, L.F.M., 2021. A comprehensive analysis of a pseudo-brittle fracture at the interface of intermetallic of η and steel in aluminum/steel joints made by FSW: Microstructure and fracture behavior. Mater. Sci. Eng. A 824, 141812. https://doi.org/10.1016/j.msea.2021.141812 Bragov, A.M., Konstantinov, A.Y., Lomunov, A.K., Petrov, Y. V., Basalin, A. V., 2018. Dynamic Deformation and Fracture Toughness of Pipe Steel, in: Procedia Structural Integrity. Elsevier B.V., pp. 1811–1816. https://doi.org/10.1016/j.prostr.2018.12.355 Chawla, K., Ray-Chaudhuri, S., Kitey, R., 2019. Interlaminar fracture toughness of short fibre reinforced GFRP laminates, in: Procedia Structural Integrity. Elsevier B.V., pp. 571–576. https://doi.org/10.1016/j.prostr.2019.05.070 Conforti, A., Minelli, F., Plizzari, G.A., Tiberti, G., 2018. Comparing test methods for the mechanical characterization of fiber reinforced concrete. Struct. Concr. 19, 656–669. https://doi.org/10.1002/suco.201700057 Eskandari, S., Andrade Pires, F.M., Camanho, P.P., Cui, H., Petrinic, N., Marques, A.T., 2019. Analyzing the failure and damage of FRP composite laminates under high strain rates considering visco-plasticity. Eng. Fail. Anal. 101, 257–273. https://doi.org/10.1016/j.engfailanal.2019.03.008 Godefroid, L.B., Cândido, L.C., Guimarães, C.R., Araújo, S.C., 2020. Failure analysis of a steel slide ring of a tubular ball mill used in an iron ore mining plant. Eng. Fail. Anal. 110. https://doi.org/10.1016/j.engfailanal.2020.104433 Kožar, I., Bede, N., Mrakovčić, S., Božić, Ž., 2021. Layered model of crack growth in concrete beams in bending. Procedia Struct. Integr. 31, 134–139. https://doi.org/10.1016/j.prostr.2021.03.022 Kožar, I., Torić Malić, N., Simonetti, D., Smolčić, Ž., 2019. Bond-slip parameter estimation in fiber reinforced concrete at failure using inverse stochastic model. Eng. Fail. Anal. 104, 84–95. https://doi.org/10.1016/j.engfailanal.2019.05.019 Liao, X., Wang, Y., Wang, Z., Feng, L., Shi, Y., 2019. Effect of low temperatures on constant amplitude fatigue properties of Q345qD steel butt welded joints. Eng. Fail. Anal. 105, 597–609. https://doi.org/10.1016/j.engfailanal.2019.07.006 Lu, D.X., Bui, H.H., Saleh, M., 2021. Effects of specimen size and loading conditions on the fracture behaviour of asphalt concretes in the SCB