新型装配式框架节点地震损伤性能研究

Seismic damage performance of a new type of prefabricated frame joints

梁柱节点的构造型式对框架结构的力学性能影响显著,该设计了一种新型装配式框架节点,为研究新型装配式框架节点的地震损伤性能,以连接方式和轴压比为设计参数,设计制作了8个节点试件进行低周循环试验,结合VIC-3D技术监测试件柱端表面应变,观察其破坏模式,分析了该节点的滞回曲线、延性和耗能能力等抗震性能指标,建立了适合于装配式节点的修正损伤模型。结果表明:新型装配式节点破坏模式为剪切破坏,主要破坏位置发生在混凝土与钢部件的连接处;装配式节点滞回曲线饱满,耗能能力强,装配式Z字形拼接节点的累积总耗能为现浇节点的1.75倍,表现出较好的抗震性能;装配式节点的延性系数在2.02~3.78,轴压比的增大会使节点承载力提高,延性降低;修正模型计算出的损伤发展曲线与实际情况吻合较好;连接方式的改变能够显著影响节点的损伤发展速率,轴压比越小,损伤发展速率越慢。最后,对装配式框架结构性态水平进行了参数量化,给出了性态水平与层间位移角、损伤指数、柱端表面峰值应变的对应关系,研究结果可为该类结构损伤评估及震后恢复提供理论依据。

The construction form of beam column joints affects the mechanical performance of frame structures.A new type of prefabricated frame joints was designed.In order to study the seismic damage performance of the new type of prefabricated frame joints,cyclic load tests were conducted on 8 joint specimens using connection mode and axial compression ratio as the design parameters.The surface strain of the specimens was monitored using VIC-3D technology.The hysteresis curve of the joint and the mechanical properties such as ductility and energy dissipation capacity were analysed.The results indicate that the failure mode of the new prefabricated joints is shear failure,with the main failure locating at the connection between concrete and steel components.The hysteresis curve of prefabricated joints is full,and their energy consumption capacity is strong.The cumulative total energy consumption of prefabricated Z-shaped splicing joints is 1.75 times that of cast-in-place joints.The ductility coefficient of prefabricated joints is between 2.02 and 3.78,and an increase in axial compression ratio will increase the bearing capacity of the joint,while the ductility coefficient will decrease.A modified damage model suitable for prefabricated joints was established,and the calculated damage development curve is consistent with the actual situation.Changes in connection methods can significantly reduce the damage development rate of joints.The smaller the axial compression ratio,the lower the damage development rate.The structural state level of prefabricated frames was quantified.The quantitative results provide a theoretical basis for damage assessment and post earthquake recovery of the structure.