阻尼器对频率法拉索索力测量的影响

Influence of Damper Parameters on Cable-Damper System Tension Measurement Using Frequency Method

振动频率法应用于索-阻尼器体系的索力计算会产生较大误差。为了考察阻尼器对频率法拉索-阻尼器体系索力测量精度的影响,采用有限元仿真分析方法,分别研究了阻尼器阻尼系数、安装高度及其刚度等因素对体系频率和索力测量的影响。研究发现,阻尼系数和安装高度对高阶频率影响显著,阻尼器刚度对低阶频率影响显著。在阻尼系数和刚度都大于其对应临界值时,拉索在阻尼器位置处近似铰支,采用修改索长方法可在一定程度上提高索力测量精度。此外,采用拉索的二阶频率可以消除垂度影响,从而改进索力测量精度。

Non-ignorable error occurs when vibration frequency method is applied to cable-damper system force measurement due to the effect of damper.In order to improve the identification precision of cable tension,a finite element simulation analysis is adopted to research on the influences of damper damping coefficient,its installation height and its stiffness on structural dynamic behaviors and cable tension measurement.It shows that damping coefficient and installation height significantly affect on structural vibration higher modes,whereas damper stiffness takes a reverse impact(lower modes).Cable can be approximately regarded as pin-supported at the damper location when both damper damping factor and stiffness are greater than their corresponding critical values.In this situation,modified effective cable length can give higher precision on cable-damper system tension measurement.The second frequency of cable can be used to eliminate the effects of damper clamp,for improving the cable tension measure precision.