基于频率、NMD和模态柔度的钢结构人行天桥模型分组修正方法研究

Research of model group updating method based on frequency,NMD and modal flexibility input for steel footbridge structures

修正后的结构有限元模型是进行结构分析的基础。对于钢结构人行天桥,由于钢材加工批次的不同,选取待修正参数时先将人行天桥各部分分组进行灵敏度分析,然后以频率、NMD和模态柔度同数量级的和最小作为目标函数,利用ANSYS的优化模块对结构进行模型修正。仿真结果表明,修正后的有限元模型计算结果与模拟结果非常接近,可以用此方法建立基准有限元模型。

Finite element model after updating is the basis for the structural analysis.For the steel footbridge structure,due to the different batches of the steel processing,the sensitivity analysis in group for each part of the footbridge was done to select the updating parameters.Then regarding the sum minimum of frequency,NMD and modal flexibility with the same order of magnitude as objective function,structure model was updated by using ANSYS optimization module.The simulation results show that the updated finite element model calculation results and simulation results are close and the method can be used to establish the benchmark finite element model.