PSI - Issue 73

Lucie Malíková et al. / Procedia Structural Integrity 73 (2025) 94–99 Author name / Structural Integrity Procedia 00 (2025) 000–000

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and is characteristic by a cone-shaped fracture in concrete starting most often from the anchor’s corner. In general, concrete cone breakout exhibits the features of the brittle failure such as sharply dropping load-displacement curves after peak load which represents rapid and unstable propagation of concrete cracks. In order to investigate the influence of various parameters both experimental and numerical studies have been performed, such as Bokor et al. (2019), Ferreira et al. (2021), Hlavička and Lublóy (2018), Krenchel and Shah (1985) or Rimkus et al. (2020). For instance, Eligenhausen et al. (2006) observed that the concrete cone circumferential cracking occurs at approximately 30 % of the ultimate load. It was also observed that the propagation of the concrete cone crack depends on the anchor embedment depth and other findings. Thus, it is evident that it is important to study how various parameters influence behavior of anchor/concrete system and its failure and/or to propose suitable prediction models. Capacity design methods often consider various parameters (such as concrete strength, depth of embedment, thickness of concrete, edge distance, concrete reinforcement, anchor material grade, forces applied to the anchor, seismic loads etc.). Several results can be found for instance in Ottosen (1981), Stone and Carino (1983), Eligehausen and Sawade (1989), Fuchs et al. (1995) or Elfgren et al. (2001) etc. Research on anchors in various concrete structures still continues in different (both experimental and numerical) ways, as works of Eshraghi et al. (2025), Chen et al. (2025), Karmokar et al. (2023) or Wu et al. (2024) proves. In this paper, the tangential stress distribution at selected radial distances from the anchor’s corner is analyzed in order to investigate the dependence of the angle, where the maximum occurs, on the value of the anchor’s outer radius. This study is carried out via finite element simulations on a proposed 2D axial-symmetric model of a steel cast-in anchor embedded in a cylindrical concrete substrate. Experimentally observed concrete cone angles are also discussed. R C critical radial distance from the anchor’s corner where the tangential stress was investigated t height of the anchor’s base  max angle where the maximum of the tangential stress occurs   tangential stress 2. Specimen and FE model parameters One slice of the cylindrical concrete specimen with an embedded steel anchor is plotted in Fig. 1; the axis of symmetry is considered on the left. The values of the individual dimensions applied within this study are presented in Table 1 and they were chosen based on previous authors’ analyses, presented for instance in Malíková et al. (2024) or Malíková and Miarka (2025). As can be seen, the outer radius of the steel anchor was varied for two selected anchor’s embedment lengths and various critical radial distances, where the tangential stress was analysed, were applied. The introduced specimen was modelled numerically via finite elements (FE) in ANSYS commercial software; particularly PLANE183 elements were utilized, see Fig. 2 where an example of the FE mesh is presented. The symmetry axis is considered on the left both in Fig. 1 and 2 which is modelled via corresponding boundary conditions. Displacement boundary conditions (positive vertical displacement of 0.05 mm) were applied also on the upper surface of the anchor, which represents the tensile loading. The hard contact boundary condition was defined between the anchor and concrete. Nomenclature L air length of the part of the steel anchor in the air L em L tot length of the part of the steel anchor embedded in the concrete substrate total length of the concrete substrate inner radius of the steel anchor outer radius of the steel anchor radius of the concrete substrate R 1 R 2 R 3