C-C扩张段材料性能设计

在相同的喷管结构中,通过正交试验和喷管结构有限元热应力分析,获得径向弹性模量、母线方向(环向)弹性模量、径向热导率、母线方向(环向)热导率、径向热膨胀系数、母线方向(环向)热膨胀系数、密度和比定压热容等八因素三水平情况下的母线方向拉应力极值、环向压应力极值和层间剪切应力极值。通过极差分析,初步获得优化的材料参数设计方案,然后对试验结果进行方差分析,得出母线方向弹性模量、径向热导率和母线方向热膨胀系数这3个因素是非常显著的;结合喷管扩张段C/C复合材料的应用环境和工艺条件,得出最终的材料优化设计方案,并进行有限元热应力分析,发现应力极值都远小于现有针刺C/C复合材料的许用应力。

Material properties design of C/C nozzle divergent section

In a nozzle structure,through orthogonal experiment and finite element analysis,the generatrix direction maximum tension stress,hoop direction maximun compressive stress and interlaminar maximum shear stress under three levels of radial elastic modulus,generatrix(hoop) elastic modulus,radial thermal conductivity,generatrix(hoop) thermal conductivity,radial thermal expansion,generatrix(hoop) thermal expansion,specific heat and density,etc.were obtained through range analysis,and optimum design scheme of parameters was preliminarily obtained.Then though variance analysis,it is found that the generatrix elastic modulus,the radial thermal conductivity and generatrix thermal expansion are three significant factors.Last,combined with C/C material application environment and technological process,the final material optimum design is presented and through finite element thermal stress analysis,it is found that the extreme stresses are far lower than allowable stresses.