Issue 39

S. Seitl et alii, Frattura ed Integrità Strutturale, 39 (2017) 100-109; DOI: 10.3221/IGF-ESIS.39.11 107 C ONCLUSIONS n this paper, the combinations of wedge splitting and three-point bending load applied on beam-shaped notched specimens are numerically analyzed. The numerically obtain data could be used for evaluation of experimentally obtain data as is shown in example. Based on the numerical results presented here, the following conclusions can be drawn:  The values of the stress intensity factor ( K I ) have the same trend in the whole range of the relative crack length  for specimen variants I, II and III, see Fig. 1.  The values of the T -stress increase with the distance of the two supports on the bottom side of the specimen, varies from negative to positive values with increasing relative crack length ( a/W eff ), for specimen variants I, II and III.  The values of COD increase in the whole range of the relative crack length ( a/W eff ) for all variants of the boundary conditions for specimen variants I, II and III.  The variant IIIb has a crack from the bottom part of the specimens, the crack growth is influenced by combination of the wedge splitting force which in turn leads to crack closure during the load of specimen, see in Fig. 6. The obtain calibration and compliance functions could be especially usefull for the published advanced model e.g. [8, 16, 20, 32]. A CKNOWLEDGMENTS he authors acknowledge the support of Czech Sciences foundation project No. 15-07210S and Brno University of Technology Project No. FAST-S-16-3475. The research was conducted in the frame of IPMinfra supported through project No. LM2015069 of MEYS. R EFERENCES [1] Anderson, T.L., Fracture mechanics fundamentals and applications, CRC Press, (1991). [2] ANSYS: Příručka ANSYS Workbench 2012, Česká technika – nakladatelství ČVUT, (2012). [3] ASTM E399-90. Standard test method for plane-strain fracture toughness testing of high strength metallic materials. Philadelphia: Amer Soc for Testing and Mater; (1990). [4] Brühwiller, E., Wittmann, F.H., The wedge splitting test, a new method of performing stable fracture mechanics test, Engineering fracture mechanics, 35 (1990) 117–125. [5] Cifuentes, H., Karihaloo, D.L. Determination of size-independent specific fracture energy of normal and high- strength self-compacting concrete from wedge splitting tests, Construction and Building Materials, 48 (2013) 548– 553. DOI: 10.1016/j.conbuildmat.2013.07.062. [6] Cifuentes, H., Lozano, M., Holusova, T., Medina, F., Seitl, S., Canteli, A., Applicability of a modified compact tension specimen for measuring the fracture energy of concrete, Anales de Mecánica de la Fractura, 32 (2015) 208– 213. [7] Guinea, G.V., Elices, M., Planas, J., Stress intensity factors for wedge–splitting geometry, Int J Fracture, 81 (1996) 113–124, DOI: 10.1007/BF00033177. [8] Havlíková, I., Majtánová, R.V., Šimonová, H., Láník, J., Keršner, Z., Evaluation of three-point bending fracture tests of concrete specimens with polypropylene fibres via double-K model, Key Engineering Materials, 592-593 (2014) 185–188, DOI: 10.4028 /www.scientific.net/KEM.592-593.185. [9] Karihaloo, L.B., Fracture Mechanics and Structural Concrete, Longman, (1995). [10] Katzer, J., Domski, J., Optimization of fibre reinforcement for waste aggregate cement composite, Construction and Building Materials 38 (2013) 790–795. DOI: 10.1016/j.conbuildmat.2012.09.057. [11] Knésl, Z., Bednár, K., Two–parameter fracture mechanics: Calculation of parameters and their values, Institute of Physics of Materials Academy of Science of the Czech Republic, (1998). I T