Thermal Analysis of Hollow Tubular Sections under High Temperatures

This work presents a numerical model for thermal analysis of steel hollow tubular sections under high temperatures. Curved and straight pipes are structural tubular elements of essential application in the fluids transport, chemical processes or energy generation plants, eventually subjected at mechanical and thermal loading conditions. Hollow tubular sections may have internal voids filled with air (hollow columns, profile sections thermally insulated or steel pipes). The internal temperature should be calculated with some simplified formulas obtained from heat transfer equations. The results obtained in this work, using the internal void formulation, were compared with the thermal response from finite element formulation, for heat conduction with internal insulation and with corresponding results obtained using the simplified heat conduction equation, according Eurocode 3. For small values of the pipe thickness, the thermal behaviour may be determined with high accuracy using one-dimensional mesh approach, with axisymmetric boundary thermal conditions across section.