基于振动测试的博物馆储藏柜动力特性分析与数值模拟

Dynamic Characteristics Analysis and Numerical Simulation of the Storage Cabinet Based on Vibration Test

地震作用下,储藏柜的加速度、速度响应及后续的防震研究均与其动力特性相关.为了得到博物馆储藏柜在不同工况下的动力特性,利用振动信号采集系统进行环境振动测试,并通过模态识别理论进行识别,分析层数、荷载参数对储藏柜动力特性的影响.建立不同层数的储藏柜有限元模型,并基于优化理论和实测结果对模型进行修正.结果表明：6层储藏柜初始状态的前两阶自振频率为13.70Hz,17.90Hz;拆解过程使储藏柜的连接变弱,自振频率降低8.8%;随着层数的增加前两阶自振频率基本呈先增加后减小的趋势.随着荷载的增加,自振频率基本呈增加的趋势,基频最大增幅在7%左右;储藏柜动力特性的变化是连接刚度与荷载大小的综合体现;修正后各个模型的动力特性与实测动力特性有较好的一致性.

The response of both acceleration and velocity of the storage cabinet under earthquake and the shockproof study are related to its dynamic characteristics. In order to analyze the dynamic characteristics of the storage cabinet under different conditions,the vibration signal acquisition system was applied in the environmental vibration test,and the dynamic characteristics were identified. The effect of layers and loads were investigated on dynamic characteristics. Finite Element Models（ FEM） with different layers were established and modified in accordance with the modal identification theory and test results. The results showed： The first two frequencies were 13. 70 Hz and 17. 90 Hz. The disassembly process weakened the connection of the storage cabinet,and frequency decreased to 8. 8%. The first two frequencies increased with the increasing of layers,and subsequently decreased as it becomes higher. The frequencies increased with the increasing of the load,and the largest rising of frequency was about 7%.Also,the dynamic characteristics of the storage cabinet were determined by connection stiffness and the load. The frequencies and mode shapes of modified FEM were in a good agreement with the test values.