黏弹性阻尼器耗能特征的温度影响分析

Analysis of temperature effect on energy dissipation characteristics of viscoelastic dampers

黏弹性阻尼器耗能特征和减震效果受环境温度影响显著。本文基于黏弹性阻尼器温度相关性试验和相似关系,得到-30~40℃下黏弹性阻尼器的滞回曲线,使用Bouc-Wen力学模型对其进行参数识别来模拟黏弹性阻尼器在不同温度下的力学性能。在Open Sees中对一座八层框架结构添加黏弹性阻尼器,进行不同温度下的非线性分析,全面考查温度对黏弹性阻尼器耗能特征和减震效果的影响。结果表明:随着温度增加,阻尼器附加刚度和附加阻尼比均减小;小震下位移减震效果随着温度增加而减小,因此要按照当地最高气温进行设计;大震下受结构弹塑性耗能影响,位移减震效果随温度变化规律不明确,因此要进行多温度下的大震弹塑性变形验算;大震与小震相比减震效果降低,大震下附加刚度起主要作用;输入地震动频谱特性对阻尼器耗能特征随温度变化规律有一定影响。本文方法和结论对黏弹性阻尼器的应用、分析和设计提供重要参考。

Mechanical property and control effect of viscoelastic( VE) damper is obviously affected by ambient temperature. In this paper,hysteretic loops of VE damper under various temperatures are obtained based on the similarity relations and temperature dependency test of VE dampers,and Bouc-Wen model is used and parametrically identified to simulate the mechanical property of VE damper. VE dampers are added into an 8-story frame structural model in Open Sees,and nonlinear analyses are executed to investigate the temperature effect on energy dissipation characteristics of VE damper. The results indicate that additional stiffness and damping ratio decrease along with the increase of temperature. The similar conclusion can be made for control effect of displacement under minor earthquake,so viscoelastically damped structure should be designed under the local maximum temperature.While the variation is not so regular and clear under major earthquake. The elasto-plastic drift check should be executed under various temperatures. The control effect under major earthquake is lower than under minor earthquake,and the additional stiffness is more dominating. The variation rule of VE damper along with the temperature change is sensitive to spectral characteristics of the input ground motions. The method and conclusions in the paper give significant reference for the analysis,design and application of structures added with VE dampers.