模态分析在塔机结构损伤中的应用研究

Modal Analysis and Its Application in Tower Crane Structure Damage

摘要: 结构健康诊断和损伤识别已经成为塔式起重机领域重要的研究课题，本文首先建立了完整的塔机动态分析有限元模型，进行了结构损伤前后的数值模拟和结果分析，结果表明，塔机各阶固有频率反映塔机的整体状态，它对局部结构的损伤不敏感，塔机振型的变化也不能很好地反映局部结构的损伤状态。提出了利用振型的变化率进行损伤诊断的方法，研究结果表明该方法不仅能很好地反映局部结构的损伤状态，而且还能准确定位损伤结构的位置，是对塔机的结构健康诊断的一种新研究思路。

Abstract: Structural health diagnosis and damage identification have become an important research topic in the field of tower cranes. A complete dynamic model of the tower crane is set up by the finite element software ANSYS. Then structures before and after damage are both simulated. The simulation results show that frequencies and modes of vibration are not sensitive to structural damage. At last, the diagnosis method of analyzing the rate of change between vibrational modes is presented. The feasibility of this method is proven by numerical simulation. This method not only diagnoses status of structure but also determines the positions of damage.