基于时域法的火箭空气舵系统频率特性分析

Frequency Characteristic Analysis of Rocket Air Rudder System based on Time Domain Method

针对火箭非线性舵系统的串联结构特点,建立空气舵系统刚度模型。基于时域法分析火箭空气舵系统频率特性,通过建立有限元分析模型得到舵系统的非线性频率特性。有限元计算结果与模态试验得到舵系统的非线性频率特性进行对比,两者一致性较好,验证了基于时域分析舵系统非线性频率特性方法的正确性。通过计算和试验得到:间隙会导致舵系统一阶频率降低,增加舵面负载和增大激振力均可消除舵系统间隙,使舵系统一阶频率随舵面负载、激振力的增大而变大。

According to the series structure characteristics of nonlinear rudder system of rocket,the stiffness model of air rudder system is established.The frequency characteristics of rocket air rudder system are analyzed by time domain method.The nonlinear frequency characteristics of the rudder system are obtained by establishing the finite element analysis model.The nonlinear frequency characteristics of the rudder system are compared between the finite element calculation results and the modal test results.The calculated results are in good agreement with the test results.The method of analyzing the nonlinear frequency characteristics of rudder system based on time domain was verified to be correct.The following conclusions are obtained through test and calculation.The clearance will reduce the uniform order frequency of rudder system.The clearance of rudder system can be eliminated by increasing the rudder surface load and exciting force.The uniform frequency of rudder system increases with the increase of rudder surface load and exciting force.