基于有限元法的桥式起重机桥架模态分析

摘要

桥式起重机在工作时由于振动或冲击会引起共振、疲劳破坏等现象,对机械装备寿命影响极大。针对设计中的桥式起重机结构进行有限元模态分析,得出了各阶模态下主梁的固有频率和固有振型,从动态刚性对该起重机的设计进行评价,利用分析所得到的参数,修改有限元模型使这些固有频率离开外激振力的频率可以避免发生共振。%An overhead traveling crane′s vibration causes resonance and fatigue damage,thus affecting the life of machinery equipment.This paper finds out the causes of the vibration and conducts the finite element（FE） modal analysis of the double-girder structure of the overhead traveling crane,obtaining the inherent frequencies and vibration modes of the girder under the modals of various orders.With the parameters obtained through the FE modal analysis,the paper modifies the FE model of the girder so that its inherent frequencies can be far away from the frequency of externally-excited vibration,thus avoiding the resonance.It provides a theoretical basis for the girder′s dynamics modification.