异常振动结构梁的动态分析与结构改造

针对国内某选煤厂在设备运行过程中整个钢结构主框架产生大幅振动现象,为找出框架振动的原因,先了解框架各构件的动力学特性。以选煤厂厂房内主框架中140钢管斜梁为分析对象,利用ANSYS软件对其进行理论模态分析,并以理论分析为参考,进行测点分布,对其进行实验模态分析,比较两种分析结果,得出该长斜梁动态特性,在此基础上对结构的振动特性做出评价,并对其在设备运行中的振动状态进行了讨论。提出了结构的改进方案。

Dynamic Measuring Technology Used in Structure Modification

The main steel frame in a coal preparation plant exist strong vibration when the equipments work, dynamic characteristic of the steel structure should be know to find out the cause of unusual vibration. In this paper, a girder of long steel tube is aimed as the analysis objects which are components of the main frame in the coal preparation plant, accomplished simulative modal Finite Element Analysis(FEA). According to the result, distributing accelerometers on the girder, experimental modal analysis was performed. After that two analysis results was compared, the dynamic characteristics of the girder of long steel tube was concluded, and its vibration state affected by the vibrating machines running was discussed. At last a proposal to modify the frame structure was put foreward. The frame vibration and noise of the modified frame structure were reduced obviously.