预应力作用下的薄壁二极铁真空室模态分析  

Modal Analysis of Thin-Walled Dipole-Magnet Vacuum Chamber under Prestress

作　　者：蔺晓建 刘建龙 马向利[1] 蒙峻[1] 杨伟顺[1] LIN Xiaojian;LIU Jianlong;MA Xiangli;MENG Jun;YANG Weishun(Institute of Modern Physics,Chinese Academy of Science,Lanzhou 730000,China)

机构地区：[1]中国科学院近代物理研究所,兰州730000

出　　处：《真空科学与技术学报》2021年第7期602-606,共5页Chinese Journal of Vacuum Science and Technology

基　　金：兰州重离子加速器运行维护任务(Y9HIRLL100)。

摘　　要：真空室受到外界激励时会产生振动,当外界激励频率接近真空室的固有频率时就会产生共振。真空室作为束流运行的场所,如果发生共振不但会影响真空系统的气密性还可能会引起结构的损伤破坏。本文结合薄壁二极铁真空室的实际使用工况,采用有限元软件分析了二极铁真空室的自由振动模态及预应力作用下的模态,得出了在自由振动情况下结构的前6阶模态固有频率基本为0,属于刚体模态,在预应力作用下结构前6阶模态固有频率在400-720 Hz范围内,并且第1和第2阶模态为整体模态,其模态特征主要集中在结构中间的薄壁和加强筋上,第3-6阶模态为局部模态,其模态特征主要集中在结构侧面的加强筋上。The vacuum chamber would vibrate when it was inspired by outside excitation,and the vacuum chamber would have a resonance when the external excitation frequency was close to it’s natural frequency.The vacuum chamber serves as a running place for the Particle beam,if the resonance occurs,it will not only affect the air tightness of the vacuum system,but also may cause damage to the structure.In this paper,based on the actual working conditions of thin-walled Dipole-Magnet vacuum chamber,the free vibration mode and the pre-stress mode of the vacuum chamber are analyzed by using finite element software.The conclusion is that the structure natural frequency of the first six order modes is 0 under the free vibration,which belongs to the rigid body mode.Under the prestress,the natural frequency of the first six order modes is in the range of 400-720 Hz,and the first and second order modes are integral modes,whose modal characteristics are mainly concentrated on the thin wall and reinforcement in the middle of the structure,while the 3rd to 6th order modes are local modes,whose modal characteristics are mainly concentrated on the reinforcement in the side of the structure.

关 键 词：薄壁真空室 有限元法 预应力 模态分析 频率 

分 类 号：TB75[一般工业技术—真空技术]