多遇地震作用下消能减震结构附加阻尼比计算方法

GB 50011-2010《建筑抗震设计规范》规定，消能减震设计计算中，主体结构基本处于弹性工作阶段时可采用线性分析方法计算，按消能减震结构总阻尼比确定地震影响系数。其中，确定消能器的附加阻尼比是计算地震响应系数的关键。基于此，总结规范方法和减震系数法两种工程中用于消能减震结构附加阻尼比计算的方法，分析两种方法存在的计算困难。由此提出适宜于计算机编程计算的自由振动衰减法，并在2个实际工程中对比这3种方法计算附加阻尼比得到地震响应的准确性。结果表明，自由振动衰减法与规范方法附加阻尼比计算结果吻合，由该阻尼比按线性分析方法计算得到的地震响应与非线性时程分析计算结果误差不大，且计算方法简便，适于工程设计；而减震系数法计算结果偏于保守，将减震系数法用于消能减震结构的计算尚有待进一步研究。

Research on additional damping ratio calculation methods under frequent earthquake

The ‘Code for seismic design of building’ (GB 50011—2010) indicates that the earthquake response of energy dissipation structures can be calculated by linear analysis method using total damping ratio to determine the seismic influence coefficient, when the main structure has no or rare nonlinear deformation. How to calculate additional damping ratio is the key. Two existing additional damping ratio calculation methods, as well as the their difficulty, were summarized, i.e. code method and horizontal seismic decrease coefficient method. To avoid the difficulty, a new method fit for computer calculation, the free vibration decrement method, was proposed. Three methods were used to separately to calculate the additional damping ratio of two real structure and compare the accuracy of the free vibration decrement method with the other two methods. The result shows that the new method is simpler to operate by a computer and has the same calculation accuracy as the code method, while the horizontal seismic decrease coefficient method needs more research.