Convective Heat Transfer Steady Thermal Stress in a Ceramic/FGM/Metal Composite EFBC Plate with Temperature-Dependent Material Properties

A NFE model is constructed to analyze the convective heat transfer steady thermal stress in a ceramic/FGM/metal composite EFBC plate with temperature-dependent material properties. Based on thermoelasticity theory, we derive the NFE basic equation of heat conduction of the plate. We present a Sinpson method for the solution of steady thermal stress formulas of the composite plate. Using FORTRAN language we design the calculation software. From numerical calculation, when (h) over bar (a) = (h) over bar (b) =1, T-a=300K, T-a=500K and T-b=1 650K, the stress distributions in the plate were obtained. The results are as follows. With the increase of the FGM gradient layer thickness, the stress distribution is more reasonable, and the largest tensile stress of the EFBC composite plate reduces by 59.6%. With the increase of m, the stress change increases obviously in metal and ceramic layers, and the thermal compressive stress on the ceramic surface reduces by 78.1%. With the increase of porosity, the change of stress at the bonding interfaces increases, and the thermal compressive stress on the surface of ceramics reaches the maximum, and the thermal tensile stress on the surface of metal reaches the maximum too. Compared with (h) over bar (a) = (h) over bar (b) =1, when (h) over bar (a) = (h) over bar (b) = 10, the tensile stress on the metal surface reduces by 91.3%, and the maximum compressive stress on the surface of ceramics increases 4.55 times. Compared with the nongraded two-layered ceramic/metal composite plate, the thermal stress of ceramic/FGM/metal composite EFBC plate is very gentle, and the maximum tensile stress reduces by 62.94%. When we consider the temperature-dependent material properties, the stress in graded three-layered composite plate becomes small obviously, and the maximum tensile stress in the plate reduces by 36.74%, and the maximum compressive stress on the ceramic surface reduces by 31.4%. The model can effectively analyze the thermal stresses and effect factors in a ZrO2/FGM/Ti-6Al-4V composite plate. The results provide the foundations of theoretical calculation for the design and application of the composite plate.