基于实测数据的电缆桥架有限元模型修正

Modification of Finite Element Modeling of Cable Tray Based on Measured Data

对电缆桥架有限元模型中螺栓连接的复杂结构进行了简化处理,基于实测数据对电缆桥架有限元模型进行了修正。应用ANSYS有限元分析软件对电缆桥架结构进行模态分析,提取了X、Y向整体振型的第1阶模态频率。为验证模型,设计了白噪声激励试验,利用随机子空间法进行模态识别,得到结构的实测频率。采用虚拟材料弹性模量对螺栓参数进行修正。修正前有限元模型模态频率与实测频率的相对误差X向为1.3%、Y向为26.7%,修正后有限元模型模态频率与实测频率的相对误差X向为0.04%、Y向为2.2%。采用修正后的电缆桥架模型进时程分析,并对模拟结果与实测结果进行了比较,结果表明修正后的有限元模型模拟结果与实测结果吻合较好,能更真实地反映结构动力特征。

The complex bolted structure of cable tray in the finite element model have been simplified, the cable tray finite element model is modified based on the measured data. The modal analysis of cable tray structure is carried out by ANSYS finite element anal- ysis software, X and Y to the overall vibration of the first order modal natural frequencies is extracted. In order to validate the model, the white noise excitation experiment is designed, and the modal identification was carried out by using the stochastic subspace identi- fication, and measured data of the structure was obtained. The bolt parameters are corrected by using virtual material. The relative er- ror of the modal frequencies and measured frequency is 1.3% in X direction, and it is 26.7% in Y direction before modification. Similarly, the relative error of the modal frequencies and measured frequency is 0.04% in X direction, and it is 2.2% in Y direction after modification. The modified cable tray model is used for process analysis, the results of simulation and experimention are com- pared, the results shows that the modified finite element model simulation results are in good agreement with the experimental results, it can be more truly reflect the structural dynamic characteristics.