Analysis of CDF and sensitivity of gust response of stochastic BAH wing structure

Uncertainty of structural parameters will lead to the uncertainty of responses of stochastic structures with stochastic excitation. The cumulative distribution function (CDF) of the response can adequately reflect the response quantity distribution. Once the CDF of the response is mastered, its statistical information may be further grasped. A sensitivity analysis of the distributed parameters of the basic variable based on the CDF of response may indicate its influence on the stochastic uncertainty of the output response, This approach shows clearly the important random variables and non-important random variables, thereby reducing the variable dimension and providing basis for design optimization. This paper employs the approximate analytical method, Monte Carlo simulation (MCS) method and a novel stratified line sampling (SLS) method to solve the CDF of the root bending moment (RBM) of a typical random BAH jet transport aircraft wing with gust excitation and the corresponding sensitivity. It is found that the masses and frequencies of the second and fifth order modals have comparatively larger influence on the CDF of gust response.