结构滞回阻尼比计算方法的改进研究

Study on Improvement of Calculation Method for Structural Hysteretic Damping Ratio

目前计算结构滞回阻尼比常用的方法是能量比法,该方法在给定滞回模型的基础上采用滞回耗能与结构总弹性应变能的比值求得结构滞回阻尼比,但该方法是建立在简谐激励下结构稳态响应的基础之上,对于真实地震下结构滞回阻尼比计算并不完全适用。考虑到这一不足,本文提出一种新的迭代计算结构滞回阻尼比的方法,在Carlos提出的结构滞回阻尼比计算方法的基础上,考虑地震激励频率对阻尼比的影响,通过改进Carlos迭代计算方法,得到了考虑地震激励频率影响的滞回阻尼比计算公式,通过该公式分析得出了不同延性系数和周期比对滞回阻尼比的影响规律,结果表明不同延性系数的结构滞回阻尼比会随着周期比的增大先增大再减小。本研究可为结构进入非线性状态后减震结构总体阻尼比的计算提供理论依据。

The energy ratio method is the commonly used technique for calculating the hysteretic damping ratio of structures,in which the ratio of hysteretic energy to the total elastic strain energy is obtained based on the hysteresis model.However,the method is based on the steady-state response of the structure under harmonic excitation,so it is not extensively applicable to calculate the damping ra⁃tio of the structure under a real earthquake.This paper proposes a new method for iteratively calculat⁃ing the hysteretic damping ratio of the structure.Based on the structural hysteresis damping ratio calcu⁃lation method proposed by Carlos,and considering the frequency of earthquake wave,the improved formula for hysteresis damping ratio calculation is proposed.The influences of different ductility coeffi⁃cients and period ratios of seismic to structure on the hysteretic damping ratio are obtained.The results show that the hysteretic damping ratio of different ductility coefficients increases firstly and then de⁃creases with the increase of the period ratio.This study can provide a method for the calculation of the damping ratio of the damaged shock-absorbing structure.