大型引射筒呼吸振动破坏机理的实验和模拟研究

EXPERIMENTS AND SIMULATIONS FOR THE FRACTURE MECHANISM INDUCED BY RESPIRATORY VIBRATION OF LARGE EJECTOR TUBE

针对某大型引射筒结构,通过有限元模拟分析,找到了对应于纵向裂纹的引射筒花瓣状呼吸振动模态及其频率;应用动应力分析,发现引起该引射筒破坏的频率主要集中在200～300 Hz的低频段.并进行了相关的模态试验,得到了典型的呼吸振动模态及频率,与计算结果进行了对比;结果表明计算与试验符合得很好,验证了数值建模与分析的合理性.

Steel ejector tube is widely used in aviation and chemical industries as an exhaust apparatus in product experiments.However,the internal high-speed airflow can result in a large number of longitudinal cracks around the cylinder.It is related with vibration modes and frequencies,as well as the stress level of the ejector tube.In this work,the petal breathing vibration mode and frequency corresponding to the longitudinal cracks in a large ejector tube structure are studied using FE analysis.With dynamic stress analysis,the frequency which leads to damage of ejector tube is found mainly in the low frequency band of 200～300 Hz. A typical breathing vibration mode and frequency were obtained through experiments,which shows that the numerical modeling and analysis are reasonable.