一种基于亚临界响应的颤振稳定性边界预测新方法

基于地面模态试验事先获取的结构模态参数，通过弹性机翼在气流中的亚临界响应，解算出作用在机翼上的非定常模态气动力系数。以弹性机翼的模态位移作为系统输入，模态气动力系数作为系统输出，通过辨识方法获得弹性机翼振动的气动力模型。在时域内耦合结构运动方程和气动力模型，建立基于试验数据的气动弹性稳定性分析模型。通过分析系统稳定性随动压的变化规律，获得弹性机翼的颤振稳定性特性。与经典颤振边界外推方法的主要区别在于该方法实质上只需要一次亚临界响应试验即可预测颤振临界点，可极大降低颤振试验的风险和成本。该方法既可用于颤振风洞试验，也可用于颤振试飞。

A New Flutter Prediction Method Based on a Structural Response at Sub-critical Speed

Based on structural model from the ground vibration test（GVT） and the structural response at sub critical speed, the generalized aerodynamic force coefficient vector can be solved. Generalized structural coordL nate vector is designed as the input and generalized aerodynamic force coefficient vector is designed as the out put. Identification technique is utilized to construct the reduced order aerodynamic model. The aeroelastic model based on experimental results can be constructed by coupling structural equation and aerodynamic equation in stable space. Analyzing the characteristics of aero-structure coupling system changing with the dynamic pres sure, the flutter onset behaviors can be solved by eigenvalue method. Different from the traditional flutter pre diction method which needs a series of sub-critical responses, this new method only need one response at sub critical speeds to predict the flutter onset. The new method can greatly reduce the cost and risk of flutter flight test or wind tunnel experiment.