基于反馈控制的桥梁节段模型干风洞实验仿真

摘要

When a bridge stays in a windy environment,the aerodynamic force makes it act as a non-classic system.For studying this,a five-parameter bridge segment model based on active control was proposed here to simalate a bridge section wind tunnel test model with eight flutter derivatives.According to the principle of equivalent force system,the proposed model constructed with the signal feedback technique coincided with the wind tunnel test model in the aspects of mathematics and mechanics.With a geometric transformation,the linear displacement signals measured in the wind tannel test could be transformed into the angular displacement signals.Meanwhile,the system's FRF matrix was obtained with the MIMO analysis technique simply and accurately.Then the control parameters were identified with the left-right eigenvectors identification algorithm based on the complex modal theory.Through simulations,the rationality of the proposed model was validated.The results revealed the application prospect of the proposed model in bridge wind-induced vibration study.%在风场作用中,针对桥梁结构与风荷载耦合而表现出非自伴随动力系统的现象,提出了仅具有5个独立控制参数的桥梁节段主动控制模型来模拟含有8个颤振气动导数的节段风洞试验模型.该模型由刚体所受的分布力系可等效为集中力系原则出发,利用PID反馈控制技术所构造,其在数学力学模型方面与风洞试验模型完全一致.通过几何变换,干风洞实验测量的线位移信号可转换为角位移信号.同时,运用MIMO分析技术可简单而精确获取系统完备的频响函数矩阵,再采用基于复模态理论中左右特征向量的辨识算法识别控制参数.通过数值仿真,验证了主动控制模型的合理性,同时也显示了该模型在桥梁风振研究中的应用价值和推广意义.