Thermal Actions and Insolation Effects in Free Standing Steel Industrial Chimneys
The technical conditions of service limit for steel structures are defined in standards and codes of practice. Horizontal displacement of the top of a chimney is usually described as a sum of the static wind displacement, the execution displacement and the ground deformation displacement. Thermal stresses and deformations are very important in concrete chimneys. In steel chimneys, usually with thin plates, according to customary standards, the problem of differential thermal stress need not be accounted for. If the temperature of chimney shaft is higher than 700C, it is advised to implement reduced values of basic properties of structural steel. For chimneys with guys, if the average temperature is higher than 500C, the influence of thermal effects on internal forces should be taken into account. Differential thermal effects in steel structure can cause corrosion and misleading temporal displacements. In the paper, the insolation effects are presented in free standing steel chimneys. The results of measured temperature and displacements are shown and discussed. The heat transmission caused by operation and solar radiation influence the horizontal displacements of steel chimneys. Because of thermal movement, the execution tolerances are usually very difficult to achieve. The thermal effects caused by solar radiation should be taken into account while designing steel chimneys.
Steel Chimney, Thermal Action, Insolation Effects
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