作　　者： ; ; ; ;

机构地区： 山东大学机械工程学院

出　　处： 《硅酸盐学报》 2003年第10期945-949,共5页

摘　　要： 采用摄动法推导出第三类边界条件下无限大对称型梯度功能材料(functionally gradient materials,FGM)平板的瞬态温度场及瞬态热应力场表达式。基于陶瓷材料的临界应力断裂判据,通过求解无限大对称型梯度功能陶瓷平板表面达到其局部断裂强度的时间,建立了引起其表面临界热应力的临界温差ΔT_c的表达式,并以此作为对称型梯度功能陶瓷的抗热震参数。通过计算实例并与均质陶瓷材料对比,分析了材料的热-物理性能分布规律对其抗热震性的影响。对高抗热震性复合陶瓷材料的研究开发具有实际意义。 The formulae of unsteady temperature fields and unsteady thermal stresses for infinite functionally gradient materials (FGM) plate with symmetrical structure under the convective boundary condition are derived by using the perturbation method. Based on the critical stress fracture criterion and by means of the calculation of the time for the surface of the functionally gradient ceramic plate to attain its local fracture strength, the expression of the critical temperature different ΔTc which can lead to the critical thermal stress at the surface as the thermal shock resistance parameter for functionally gradient ceramics with symmetrical structure is obtained. The effects of the distributions of thermo-physical properties on the thermal shock resistance of the functionally gradient ceramics are analyzed via numerical calculations in contrast to homogeneous ceramics. It would be valuable for the development of composite ceramics with high thermal shock resistance.

关 键 词： 梯度功能材料 抗热震性 临界温差 无限大平板 非稳态热应力

领　　域： [化学工程] [化学工程]