设备激励下山西河津电厂结构振动测试研究

Dynamic Test on One Structure in Shanxi Hejin Thermal Plant Under Equipment Excitations

利用测振仪对设备激励下大型电厂钢桁架-管柱混合结构体系的扭转振动、竖向振动和水平振动进行了现场试验,采用DASP程序对试验数据进行了时域分析和自谱分析,并结合有限元模拟结果,系统研究了结构的振动响应、横向位移、纵向位移、竖向位移、变形、转角、振型及频率等关键性能指标。结果表明:结构各特征位置处的测点振动响应曲线不同,同一测点南北与东西向的位移峰值不同步出现,说明结构南北与东西向的振动性能不同;角部的振动位移比中间大,结构出现自身变形和扭转;结构低阶振型接近,存在耦合,说明该结构不适合用底部剪力法计算地震作用;上部结构的相对变形小于其下部结构,顶部A形架的振动出现回缩,说明结构的质量和刚度在A形架处有突变。计算结果与试验结果吻合较好,模态分析结果能为结构动力响应研究提供理论依据。

The torsional vibration,vertical vibration and horizontal vibration of a steel truss-pipe column hybrid structure system of large power plant under equipment excitations are tested by vibrameter.The time domain analysis and self-spectrum analysis of test data are carried out by DASP program,and the finite element simulation results are combined.The key performance indexes such as vibration response,lateral displacement,longitudinal displacement,vertical displacement,deformation,Angle,mode and frequency of the structure are systematically studied.The results show that the vibration response curves of the measuring points at each characteristic position of the structure are different,and the displacement peaks of the same measuring point are not synchronized,which indicates that the vibration performance of the structure is different in the North-South direction and the east-west direction.The vibration displacement of the corner is larger than that of the middle,and the structure has its own deformation and torsion.The low order modes of the structure are close and there is coupling,which indicates that the structure is not suitable for the calculation of seismic action by the base shear method.The relative deformation of the superstructure is smaller than that of the substructure,and the vibration of the A-shaped frame at the top is retracted,which indicates that the mass and stiffness of the structure change abruptly at the A-shaped frame.The calculated results are in good agreement with the experimental results,and the modal analysis results can provide a theoretical basis for the study of structural dynamic response.