火箭发动机旋转试验台高速轴振型计算与分析

COMPUTATION AND ANALYSIS OF HIGH-SPEED SHAFT MODE SHAPES IN ROTATING TEST-BED FOR ROCKET ENGINE

研究了火箭发动机高速旋转试验台高速轴在工作激振频率内的振型.用有限元分析软件ANSYS对高速轴刚性、弹性2种不同的支撑情况分别建立了有限元模型,计算了轴的前四阶振型,进行了分析比较.计算结果表明,在一定范围内,弹性支撑时固有频率将降低,选取不同的弹性系数k值对固有频率的计算结果影响很大.当超出该范围时,进一步增加弹性系数k对固有频率几乎没有影响,此时已接近或完全等同于刚性支撑.

The mode shapes of the high-speed shaft in rotating test-bed for rocket engine within working excited frequencies were studied. Based on ANSYS software of FEM（Finite Element Method）, two FEM models of the high-speed shaft were established according to stiff support and elastic support. The anterior four-step mode shapes were computed and analyzed. It is shown that the natural frequency of high-speed shaft reduces at elastic support within certain range of elasticity coefficient k, and different k affects the results significantly. Overstepping the range, the natural frequency is hardly affected with the increase of k, and the support is approaching or equal completely to the stiff one.