弹性导弹的连续与离散阵风响应

导弹在空中飞行时会受到阵风的干扰,过大幅值的阵风响应可能影响结构安全 、飞行性能及攻击精度.为此,基于导弹刚体/弹性耦合运动方程和准定常气动力,建立了导 弹气动伺服弹性系统的连续与离散阵风响应分析方法.对于连续阵风,通过频率响应函数来 计算响应的功率谱密度;对于离散阵风,则在状态空间方程的基础上时间积分求得响应历程 .以某导弹为例,进行了气动伺服弹性稳定性分析、连续和离散阵风响应分析,并提出了飞 行控制系统的改进设计.数值结果表明,结构与控制之间的不利耦合可能使系统的稳定性和 阵风响应特性恶化,在控制回路中增加合适的结构陷波器可有效减小弹性模态的不利影响.

Continuous and discrete gust responses of elastic missiles

Elastic missiles in atmosphere may have intense response due to gust excitation,which has great influence on structural safety,flight performance,and attack precision.Approaches of the calculations of aeroservoelastic response to the continuous and discrete gust for missiles were presented.The equations of motion considered the interaction of rigid-body modes and elastic vibration modes,and the generalized aerodynamic forces were formulated in a way of quasisteady aerodynamics.The approach of the continuous gust response was based on the calculation of the power spectral density(PSD) using frequency-domain transfer functions.The approach of the discrete gust response was a time-domain integral based on the state-space formulation of the aeroservoelastic system.An actual process of evaluating aeroservoelastic stability,calculating continuous and discrete gust response,and modifying flight control system for a cruise missile was demonstrated.Numerical results indicate that adverse coupling between structure and control system may deteriorate the stability and gust response of the system.An appropriate structural notch filter in the control loop can effectively alleviate the adverse effects of elastic modes.