PSI - Issue 6

R.V. Fedorenko et al. / Procedia Structural Integrity 6 (2017) 244–251 Fedorenko R. et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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3. Material models and software verification For the purpose of verification of the mathematical models and engineering methods used in reinforcement concrete buildings strength analysis under different loads (static and transient temperature, structural and other loads), severalcomputational simulations were carried out. Experimental data for these verificatory tasks was found in periodicals. 3.1. Uniaxial compression of the cylindrical concrete specimens In the article [9] there are given the results of a series of uniaxial compressive tests of concrete specimens. Cylindrical specimen with 100mm diameter and different length are under consideration. Concrete mixture and its compression strength grade were varied. In the course of tests the total vertical action as a function of the vertical displacement was recorded, with the aid of the force and displacement sensory system (in some experiments strain sensory system was used). Based on this dependence the stress-strain curves were calculated. Numerical simulation was implemented with ABAQUS CAE system. “Concrete damaged plasticity” model was used. Mechanical properties of concrete were specified by data in [9]. Concrete nonlinear deformation curve and other properties, not given in [9], where specified according to standards [10]. Contact friction on the surface between concrete and steel was not considered. Load was applied by the vertical displacement assignment of the upper plate. During the simulation total contact pressure on the top of concrete specimen was monitored. Situation of monotonous kinematic loading was analysed. Computation was made by using explicit integration scheme in ABAQUS Explicit program. Figure 1 shows the distribution of compression scalar stiffness degradation factor.

Fig. 1.Compression scalar stiffness degradation distribution.

Analysis of the procured deformation curves of the cylindrical concrete specimens by finite element method shows good agreement with experimental data. Ultimate stresses and corresponding strains were found with an error less than 10%. 3.2. Reinforced concrete beams analysis under the static loads. In the article of the authors Bresler, Scordelis [11] the results of the reinforced concrete beams verification test under the static loadsare presented. Further on this test run was reproduced by Vecchio, Shim. They published the results of two test runs comparison in [12]. 12 beams were regarded with different geometrical dimensions, material properties of the concrete and steel and reinforcement distribution. During the experiments displacement of the beam central section as a function of the external force was recorded. Visual registration of the cracks and damages in concrete was performed. Figure 2 (a) shows photos of specimens OA3, A1 and B1 at the end of the experiment.