Issue 39

V. Salajka et alii, Frattura ed Integrità Strutturale, 39 (2017) 88-99; DOI: 10.3221/IGF-ESIS.39.10 98 Figure 20 : Principal stress σ 3 field. Figure 21 : Nonlinear strains ε pl field. A NALYSIS OF BEHAVIOR OF CYCLIC LOADED CLAY BLOCK WALLS wo detailed three-dimensional computational models of the structures of the masonry walls from the precise masonry clay blocks POROTHERM 44 T Profi assembled on the thin joint mortar, including the girders, the concrete blocks and auxiliary elements were created using the finite element method in the ANSYS software system. The crucial parts of the model including the clay walls were created from solid elements in the shape of a hexahedron. Four alternatives depending on the wall lengths and the intensity of the vertical preload were solved. They were the walls 2,750 mm high and 440 mm wide with the different length. The two long walls of the 2,500 mm length are marked “L” and the two short ones of 1,500 mm are marked “S”. The preload including self-weights of the girders and of the concrete block corresponded to the load at the amount of approximately 1/3 f cd and 2/3 f cd of the walls. The calculations were labelled L1, L2, S1 and S2. The material properties of the clay blocks are nonlinear. A material model corresponding to the model of the “concrete” with the modified Drucker–Prager model was chosen. The model is suitable for a calculation of structures made of concrete, cement, stone and brick. The calculations are based on the assumption that the walls are loaded by the cyclically forced loading corresponding to the shear tests of the walls of the actual size. Boundary conditions of the conducted tests had to be considered complexly in the calculations. For instance, the method of modelling the compressive device proved to be affecting the calculation stability significantly and thereby the possibility convergence of the solution. T