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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。
Based on the first-order uniform straight-wing aircraft, a quantitative risk assessment and parameter sensitivity analysis method based on probability flutter was established to reduce the probability of flutter failure. The generalized Hamilton principle is used to establish the structural equation of motion. The flutter velocity of the structure is obtained through eigenvalue analysis. Assuming that the structural parameters in the model all satisfy the normal distribution, the probability distribution of flutter failure at different given velocities is obtained by Monte-Carlo method. Based on this, the flutter velocity structure with flutter failure probability of 0.1% The line sampling method is used to study the parameter sensitivity to get the important influence parameters that affect the flutter failure. The results show that the probability of flutter failure can be reduced by decreasing the expected value and variability of chord length, or by increasing the expected values of bending and torsional stiffness.