考虑结构参数不确定性的概率颤振分析
Probabilistic Flutter Analysis Considering Uncertainties of Structural Parameters

以一等剖面均匀直机翼为研究对象建立一套基于概率颤振的定量风险评估和参数灵敏度分析方法，以降低颤振失效发生的概率。运用广义Hamilton原理建立结构运动方程，通过特征值分析得到结构的颤振速度。假设模型中的结构参数均满足正态分布，采用蒙特卡罗法得到在不同给定速度下发生颤振失效的概率分布，在此基础上选取颤振失效概率为0.1%时的颤振速度构造线抽样法进行参数灵敏度研究以得到影响颤振失效的重要影响参数。结果表明，减小展长和弦长的期望值和变异性，或者提高弯曲和扭转刚度的期望值，均可以降低颤振失效的概率。
A uniform straight wing was selected to develop an uncertainty quantification and parameter sensitivity analysis method based on the probabilistic flutter. Firstly, the structural equations of motions were presented by applying the extended Hamilton's principle, and a certain flutter velocity was obtained by analyzing the eigenvalue solution. The probabilistic distribution of flutter failure was estimated by using Monte Carlo simulation considering random uncertain variables to satisfy normal distribution. Then line sampling technique was developed to select the important parameters by using the sensitivity analysis under 0.1% probabilistic flutter failure. Finally, the results indicated that the decrease in the mean and the variability of the length of span as well as chord, or the increase in the mean of bending stiffness and torsional stiffness could reduce the probability of flutter failure