ECBC边界下夹FGM金属/陶瓷复合板稳态热应力

采用有限元法研究ECBC边界下中间夹FGM金属/陶瓷复合板的稳态热应力问题,检验了研究方法的正确性,给出了该材料复合板的稳态热应力场分布(Ta=500K,Tb=1800K)。结果表明,FGM层厚度的增加对ECBC复合板的稳态热应力影响不明显。当M=1时,热应力曲线平缓而光滑;当M=0.1和10时,热应力曲线出现明显的转折点;随着FGM层孔隙率的增大,三层板的衔接界面处,热应力变化增大,曲线出现钝角;与金属/陶瓷二层复合板界面处热应力出现突变相比,夹FGM金属/陶瓷复合板的热应力非常缓和。此结果为该复合板的设计和应用提供了准确的理论计算依据。

STEADY THERMAL STRESSES IN METAL-FGM-CERAMIC COMPOSITE PLATE UNDER ECBC MECHANICAL BOUNDARY

The steady thermal stress in the metal-FGM-ceramic composite plate under ECBC mechanical boundary was analyzed by the finite element method.The accuracy of this method was examined.The stress distributions during heating process(Ta=500K,Tb=1 800K)were obtained.The results show that,the increase of FGM layer thickness has no distinct effect on the steady thermal stress in the composite ECBC plate.When M=1,the thermal stress curve is relaxed and smooth;when M = 0.1and 10,the thermal stress curves appear distinct turning point.With the increase of FGM layer porosity P,the change of thermal stress in the transition region from the pure metal or ceramic to the graded material increases,the thermal stress curves appear obtuse angle.The thermal stress in graded plate has no sharp changes and very relaxed as compared with that of nongraded plate.The results provide the foundations of theoretical calculation for the design and application of the composite plate.