身管固有频率高效全局灵敏度分析

摘要

In order to obtain a barrel's key parameters affecting its natural frequencies,the polynomial chaos expansion was used to describe the relation of its natural frequencies and its structural parameters.The adaptive expansion strategy for the polynomial chaos based on the sensitivity was proposed to obtain polynomial chaos expansions with different orders.The important terms and corresponding expansion coefficients were obtained automatically by using the least absolute shrinkage and selection operator (LASSO).Based on the orthogonality of the polynomial chaos,the global sensitivity factors for structural parameters of the barrel were obtained directly with coefficients of the polynomial chaos expansion.Example 1 indicated that the proposed method can select expansion orders according to the importance of variables.A benchmark example was presented to demonstrate the effectiveness and higher efficiency of the proposed method.In addition,the numerical examples of barrels indicated that the position of the front fulcrum of the cradle,the corresponding cylinder diameters of barrels and the diameters at barrels muzzles are the key parameters affecting lower order natural frequencies of barrels.%为获得影响身管固有频率的关键参数，将身管固有频率写成其参数的混沌多项式形式，提出基于灵敏度的混沌多项式自适应展开，采用 LASSO（Least Absolute Shrinkage and Selection Operator）自动选择重要项及其展开系数，根据混沌多项式的正交性直接由混沌多项式展开系数解析获得身管参数的全局灵敏度因子。算例1表明基于灵敏度的多项式自适应展开能够根据变量的重要性选择多项式的展开阶数，算例2通过一个标准模型验证提出方法的有效性和高效性。此外，身管算例表明对于低阶固有频率摇架前支点位置及对应的身管圆柱段直径和身管炮口处直径为核心关键参数。