【摘要】 在陶瓷材料临界应力断裂理论的基础上,通过分别求解无限大平板、无限长圆柱体和球体三种形状构件在第三类边界条件下的瞬态温度场及瞬态热应力场,研究了不同形状陶瓷构件的热冲击行为,并据此分别建立了引起三种形状陶瓷构件表面临界热应力的临界温差表达式作为它们的抗热震参数。计算结果表明,在相同Biot模数的条件下,无限大平板表面达到临界热应力的量纲-时间最长,无限长圆柱体次之,圆球体表面达到临界热应力的量纲-时间最短;圆球体的临界温差最大即抗热震性最好,无限长圆柱体次之,无限大平板的抗热震性最差。更多还原

【Abstract】 Based on the critical stress fracture theory for ceramic materials, the thermal shock behaviors of ceramic components with different shapes are investigated by means of the calculations of transient temperature fields and transient thermal stresses for infinite plate-, infinite cylinder- and ball-shaped components under the convective boundary conditions respectively, according to which the formulae of critical temperature difference leading to the critical stress at the surface as thermal shock resistance parameters for these three shapes were obtained respectively. The calculation results reveal that the dimensionless time for the surface to attain the critical thermal stress for infinite plate is the longest, infinite cylinder takes the second place, while the dimensionless time for the surface to attain the critical thermal stress for ball is the shortest in case of the same Biot numbers. The critical temperature difference for ceramic ball is the highest, i.e. the thermal shock resistance is the highest, infinite cylinder takes the second place, whereas the thermal shock resistance of infinite plate is the lowest.更多还原