ên13th International Conferenceon Fracture June 16–21, 2013,Beijing, China -4- ܷ ஶሺ ݐ ሻൌܷ ሺܷ െܷ ሻ ܪ ሺ ݐ െ߬ ሻ (6) ܫ ሺ ݐ ሻൌ ܫߛ ൫1െ ܪ ሺ ݐ െ߬ ሻ൯ (7) Where, ܪ ሺ ݐ െ߬ ሻis the Heaviside mathematical function (step function) definedby ܪ ሺ ݐ െ߬ ሻൌቄ 0, ݐ 1, ൏߬ ݐ ߬ (8) Other variables of the problem are: ܭ ൌ1,19 W/m°C: Thermal Conductivity of the equivalent wall; ߙ ൌ6,33 ൈ10ି m²/seg: Equivalent Thermal diffusivity. Single value of thermal diffusivity for the entire coating structure; ݀ ൌ25,15cm: Total thickness of the wall where the structure of ceramic coating, outward looking; ݈ ଵ ൌ2cm: Thickness of plaster layer facing the interior of the building. Not part of the structure of the ceramic coating; ݈ ଶ ൌ20cm: Thickness ofthe masonry wall layer. Substrate where theceramic coating structure is applied; ݄ ൌ9W/m² °C: Coefficient of air heat transfer from inside the building into the wall structure where the internal plaster layer lays; ݄ ൌ18W/m² °C: Coefficient of atmospheric air heat transfer from outside the building into the wall structure where the ceramic coating lays; ܷ ൌ21°C: air temperature inside the building where is the wall subjected to thermal shock; ܷ ൌ34,60°C: Temperature of the atmospheric air outside the building moments immediately prior to the occurrence of thermal shock; ܷ ൌ22,14°C: Temperature of the atmospheric air outside the building moments immediately following the occurrence of thermal shock; ߣ : : Eigenvalues obtained numerically by the following equation: ܿߣ ݀ߣݏ െఒమ ݀ߣ ݊݅ݏ ݀ߣ ݊݅ݏ ఒܿ ݀ߣݏ ൌ0 (9) ܨܥ : Coefficients of Fourier Series describing the temperature distribution; ߛ : Coefficient of Solar Radiation Absorption of ceramic coating. Worth 0.45 to 0.95 for clear anddark ceramic pottery. ܫ ൌ692W/m²: Solar Thermal Energy Incident on the ceramic surface, moments immediately prior to heat shock. The values of the parameters described were obtained in Saraiva (1998), Moaveni (2008), Uchôa (2007) and Rosa (2001). Thus the modeled thermal shock itself contains a mathematical simplification, which consists in the instant change of atmospheric conditions in contact with the
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