结构非线性风振的路径积分方法

通过引入相关脉动风速滤波，将结构非线性风振方程转变为Ito随机微分方程的形式；该方程的解过程具有Markov性质．在时域内将状态方程展开，利用其瞬时线性化随机方程的解析解，基于路径积分给出了结构非线性风振响应概率密度的形式解，得到了一种分析结构非线性风振响应的新方法．对桅杆算例的数值分析表明，该方法较线性频域分析方法和非线性时域积分方法具有更好的准确性和有效性．

Path Integral Solution of the Nonlinear Dynamic Behavior of Structure Under Wind Excitation

A numerical scheme for the nonlinear behavior of structure under wind excitation is investigated.With the white noise filter of turbulent-wind fluctuations,the nonlinear motion equation of structures subjected to wind load was modeled as the Ito's stochastic differential equation.The state vector associated with such a model is a diffusion process.A continuous linearization strategy in the time-domain was adopted.Based on the solution series of its stochastic linearization equations,the formal probabilistic density of the structure response was developed by the path integral technique.It is shown by the numerical example of a guyed mast that compared with the frequency-domain method and the time-domain nonlinear analysis,the proposed approach is highlighted by high accuracy and robustness.The influence of the structure non-linearity on the dynamic reliability assessment is also analyzed in the example.