基于参数识别的桥梁冲击系数随机响应优化方法

Numerical Method Study of Key Factor Identification and Parameter Optimization for Dynamic Impact on Bridge Based on the Pseudo-excitation Method

随着行车速度的不断增高,路面高低随机不平顺引起车桥结构强烈的耦合振动严重影响工程结构的服役性能,乘客舒适性、桥梁及车辆的安全性受到大量的关注。在设计领域,动力学分析及优化受到诸多困难的干扰。将虚拟激励法与辛数学方法相结合对车桥系统动态响应进行数值分析,基于正交分析技术建立影响因素强度分析,以识别设计因素的相对重要性,例如车辆重量、刚度、速度、轨道不平顺、接触模型、桥梁跨度、支撑形式和材料参数。基于参数重要度推导基于虚拟激励法的高效灵敏度分析方法用于优化关键因素,并用数值算例证明了方法的准确性和计算效率。结果表明,影响桥梁各个位置的因素差异很大,冲击系数随着桥表面的粗糙度增加而增加,影响因素主要是车辆悬架刚度、阻尼和速度参数,并通过参数优化有效降低了主要影响因素对桥梁的影响。

Because of increased vehicle speed, engineers must pay more attention to the comfort of passengers and the safety of trains and bridges. This requires analysis and optimization of factors that may affect the dynamic behavior of the vehicle-bridge system. The need for a large number of repeated random vibration computations for complicated vehicle-bridge coupling systems causes serious difficulties in design. These difficulties have been overcome by combining the pseudo-excitation method with the symplectic mathematical method. The orthogonal experimental approach is used to identify the relative importance of factors affecting design such as vehicle weight, vehicle stiffness, velocity, track irregularity, contact model, bridge span, support style and material parameters. An efficient sensitivity analysis method based on PEM is used to optimize the key factors. Numerical examples demonstrate the accuracy and efficiency of the model. The results show that the factors impacting various positions on the bridge differ greatly. Impact factors increase with increased roughness of the bridge surface. The primary parameters that affect the impact factors are the bridge suspension stiffness, damping, and vehicle velocity. The impact of factors affecting the bridge is effectively decreased by parameter optimization.