ên13th International Conferenceon Fracture June 16–21, 2013,Beijing, China -7- the center of the first ceramic; BB' passing through the layer of grout, and CC 'passing through the ceramic core. Therefore, the influence of ceramic and cross-sectional analysiswere evaluated. 6.1 Temperature Distribution As explained in the item 4, we adopted the simplifying assumption that, before the heat shock, the coating structure presented steady state temperature distribution. Therefore the most critical condition in which the structure has higher temperatures is the initial. When the thermal shock atmospheric occurred, the coating structure begins to gradually lose heat to the air, seeking new situation of steady state, with higher speed of temperature decrease in the first few minutes. The clear ceramic shows lower temperatures than the dark because it has a lower coefficient of thermal absorption. Figure 5 – Temperaturesobtained for ceramics dark and clear 6.2Analysis of stresses Considering that the highest temperatures are shown at the beginning, also the highest stressesare present at that moment. Because the model with clear ceramic works with lower temperatures, stresses values in this model were lower when compared with the dark ceramic. During the cooling of the layers of the structure, due to thermal shock, there is also the relief of the stresses that request it. Negative values indicate compressive stresses, and the positive tensile stresses. With regard to stresses SX, it was found that the models worked with compressive stresses in all three layers. This is due to the fact that when the structure is heated before heat shock, it tends to swell; however, their deformation is prevented by the boundary conditions of zero displacement at the ends. From here the compressive stress analysis are originated. The ceramic pieces in sections AA 'and CC' have the highest stress values because they have the higher modulus of elasticity (41.6 GPa). Because of high modulus of elasticity, the ceramic ultimately absorb much of the compressive stress that would be passed on to lower layers. Moreover, the grout atBB’ top is significantly less rigid than the ceramic (modulus of 7.879 MPa) and therefore ends up being compressed by the ceramic part, deforming and allowing major deformations, thus,allowing the passage of more stresses for the subsequent layers of adhesive mortar and plaster, which is why 35 40 45 50 55 60 0.000 0.005 0.010 0.015 0.020 0.025 0.030 Temperature (°C) y position in structure (m) Dark Ceramic shock 15 min 30 min 45 min 60 min 120 min 30 35 40 45 50 0.000 0.005 0.010 0.015 0.020 0.025 0.030 Temperature (°C) y position in structure (m) Clear Ceramic shock 15 min 30 min 45 min 60 min 120 min
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