Study On Steady Thermal Stress In The Metal-ceramic Composite Plate With An Interlayer Of Fgm And Temperature-dependent Properties

Functionally graded material (It is called FGM for short) is a kind of non-homogeneous material, whose composition structure and performance is gradient in space. This material is the product of aerospace research. Because of high temperature, corrosion and wear resistant properties, FGM is worth researching. So far, thermal stress analysis is one of the research interests. The finite element method is effective to solve thermal stress analysis, because it is a combination of computer and numerical analysis and able to solve problems with complicated boundary conditions.This paper selects ceramics/metal FGM and ceramics/metal composite plates as research object. In order to study ceramics/metal FGM composite plate, some studies have been done as follows.(1) Firstly, the calculation models of the two kinds of composite plates have been established. Then one-dimensional finite element equation of the composite plates has been derived by analyzing the functional of the heat conduction problem. One-dimensional finite element program was written by Fortran language.(2) Using Fortran language the subroutines of material properties and Simpson numerical integration were written. Combining subroutine of material properties and finite element equation the values of material properties were obtained, then the results were put into subroutine of Simpson numerical integration to obtain steady thermal stress of composite plates.(3) By comparing with the existing literature, he numerical integration method applied by this paper has been proved to be correct.(4) From numerical calculation, the results are as follows.(a) The variation of FGM layer thickness will induce the variations of the steady heating temperature fields and the thermal stress fields of the middle part in the ECBC and ECBF composite plate with constant and variable material properties. The FGM layer is thicker, the temperature and thermal stress distributions in the plate tend to gentle and are more reasonable.(b) Changing the material composition M strongly influence on temperature distribution curves in variable ,steady heating temperature field and the thermal stresses of ECBC,ECBF composite plates. When M=1, unlike M=0.1 and M=10 shows apparent turning point, the curve is the most reasonable.(c) Porosity influence much on temperature distribution curves in variable, steady heating temperature field and the thermal stresses of ECBC,ECBF composite plates.(d) The existence of FGM layer influence much on temperature distribution curves in variable ,steady heating temperature field and the thermal stresses of ECBC,ECBF composite plates. Apparently, the composite plate with FGM layer are much better than that without.(e) The upper and lower surface temperatures Ta and Tb influence much on temperature distribution curves in variable, steady heating temperature field and the thermal stresses of ECBC,ECBF composite plates.