耗能腋撑钢筋混凝土框架结构减震分析

Vibration reduction analysis of the new system of reinforced concrete frame with energy dissipation haunch braces

结合某工程算例,分别利用ETABS和PERFORM-3D软件对比分析了金属阻尼腋撑、黏滞阻尼腋撑、钢筋混凝土腋撑和普通框架结构在小震和大震作用下的整体抗震性能,并分析了小震下腋撑设置对框架梁柱内力的影响。结果表明:在小震和大震下,带腋撑框架结构的层间位移角都比普通框架的小,其中黏滞阻尼腋撑框架平均减震幅值最大,分别为51.3%和43.4%;层剪力最小的是黏滞阻尼腋撑框架,平均减震幅值分别为52.8%和16.97%。小震下金属阻尼腋撑主要提供结构附加刚度,其与钢筋混凝土腋撑对框架梁柱内力影响一致,均使梁柱节点处弯矩和剪力减小但轴力增大,而黏滞阻尼腋撑使梁柱内力均减少。大震下金属阻尼腋撑和黏滞阻尼腋撑框架的损伤程度较轻,金属阻尼和黏滞阻尼腋撑的耗能分别占到了24.66%和39.33%,显示出了耗能腋撑良好的减震作用。

Combined with an engineering example,software of ETABS and PERFORM-3D were used respectively to study the overall vibration reduction effect of framework of metal damper haunch braces(MDHB),viscous damper haunch braces(VDHB),reinforced concrete haunch braces(RCHB) and general under small and big earthquakes.Besides,changes of the internal force of beams and columns due to haunch braces(HB)were analyzed.The analysis results indicate that inter-story drifts of HB framework are all smaller than general framework's.Among them,the biggest average vibration amplitude is VDHB which can be reached 51.3% and 43.4% respectively,the smallest story shear is VDHB whose average vibration amplitude can be reached 52.8% and 16.97% respectively.In small earthquakes,MDHB mainly provides additional stiffness to the frame,so its effect on the internal force of beams and columns is consistent with RCHB,which can make the beam-column joint moment and shear forces decreased while axial force increased.However,the beam-column joint internal forces of VDHB are all decreased.In big earthquakes,the lesser damage of all components is the framework of MDHB and VDHB,with the energy dissipation of MDHB and VDHB is accounted for 24.66% and 39.33% respectively.So it represents the good vibration reduction effect with energy dissipation HB.