钢与钢筋混凝土混合结构等效阻尼比计算分析

Calculation and analysis of equivalent damping ratio of composite structure with steel and reinforced concrete

在复阻尼假定下,通过能量守恒原理推导出适用于以剪切变形为主的钢与钢筋混凝土混合结构在双向振动下的等效阻尼比的简化公式,该公式较为适用于工程应用.采用SAP2000有限元软件建立一个钢与钢筋混凝土混合结构的模型进行分析,并用该简化公式计算等效阻尼比,最后在SATWE中采用该阻尼比与在PMSAP中采用由不同材料单元的阻尼矩阵叠加(通常为非比例阻尼)选项进行抗震分析对比,证明该简化公式是适用的.

On the assumption of complex damping, a computational formula of equivalent damping ratio was derived with the principle of energy conservation for the shear deformation of the composite structure with steel and concrete and subjected to bi-directional vibration. This formula would comparatively be suit- able for engineering application. A model of composite structure with steel and concrete was established and analyzed by using the finite element software SAP2000 and its equivalent damping ratio was evaluated by using the simplified formula. Finally, two categories of equivalent damping ratio were used to carry out the antiseismic analysis and contrast, one being the forgoing damping ratio in SATWE and the other being the damping matrix superposition of structural material units （usually a non-proportional damping） in PM- SAP. The results showed that the simplified formula would be suitable for engineeriflg application for determing the damping ratio of composite material.