摘 要： 混合结构由于其建筑及功能上的种种优点，在现代建筑中得到广泛应用。对这类结构进行分析时，主要有两个问题：一是在考虑不同材料的情况下，结构的整体阻尼比如何计算；二是在整体阻尼比的计算结果下，如何针对小阻尼材料进行修正。本文以高楼顶加钢塔的这一混合结构形式为例，建立了一种非比例阻尼矩阵的构造方法，计算结果表明该构造方法得到的振型阻尼比可以较好的反映对主体结构和顶部钢塔影响最大的4阶振型的耗能特点。此外，本文基于反应谱法推导了顶部钢塔在整体阻尼比（第一阶主振型的阻尼比）计算下的误差，在此基础上，给出了相应的修正公式，最后采用上述方法分析了洛阳某高层顶部钢塔的地震响应。

Abstract: Since the architectural and functional advantages, composite structures have been widely applied in modern architectures.There are two main problems on the study of such structures: first is the calculation of damping when considering different materials; the other is the modification of low damping material after integral calculation using the integral damping ratio. Taking the high-rise building with steel tower on top for example, this paper suggests a construction method of non-classical damping matrix. The result shows the damping ratio based on this matrix can reflect the energy dissipation of 4 modals which describe the most of the main structure and the steel tower on top. Basing on the response spectrum method, this paper deduced the inaccuracy of the steel tower’s result when calculation on the integral damping ratio. According to the inaccuracy, this paper suggests a modification formula. The comparison with the accurate result shows the modification factor obtained by this formula has certain reference value