古建筑直榫节点扁钢与阻尼器加固比较研究

Comparative Research on Flat Steel and Damper Strengthening of Straight Type of Tenon-Mortise Joints

为更好地对古建筑木结构进行抗震加固,基于直榫节点力学模型,以汶川地震中受损的青城山黄帝殿为例,对直榫节点分别采用扁钢和阻尼器加固,对比分析了加固前后结构的自振周期、节点加速度放大系数以及被加固节点相邻杆件的内力.结果表明:2种加固方法均能提高结构的抗震性能,但扁钢加固加大了节点刚度和部分相邻构件的内力,易导致相邻节点拔榫破坏;阻尼器加固可在不增大节点刚度的条件下,减轻结构的地震响应,加固节点的加速度放大系数降低12.8%,加固节点相连杆件的拉力、剪力和弯矩分别平均降低48.3%、40.6%和52.1%,起到了耗能和防止拔榫的作用.

For better seismic reinforcement of Chinese ancient wooden buildings, based on the mechanical model for straight type of tenon-ortise joints the flat steel strengthening and damper strengthening of straight type of tenon-mortise joints were investigated respectively by taking the Yellow Emperor Temple in Qingcheng Mountain damaged vibration period of the structure, the acceleration in the Wenchuan earthquake as an example. The magnification factor of a strengthened joint and the internal force of adjacent members of the strengthened joint were analyzed by using the two strengthening measures, and compared with those of the original structure. The analysis results indicate that the seismic performance of the structure is significantly improved by the two strengthening measures. However, the flat steel strengthening will increase the structural stiffness of the strengthened joint and the internal forces of its adjacent members to easily result in pulling-out-tenon of adjacent joints. The damper strengthening can significantly weaken the seismic responses of the structure without increasing joint stiffness and reduce the acceleration magnification factor of the strengthened joint by 12.8% and average tension force, shear force and bending moment by 48.3% , 40.6% and 52.1% respectively, so the damper strengthening has the effects of energy dissipation and preventing pulling- out-tenon.