低损伤预应力自复位装配式混凝土耗能框架节点试验和数值研究

为了提高传统预应力干连接节点的抗震性能，提出一种带软钢阻尼器的低损伤自复位装配式混凝土（self-centering precast concrete，SCPC）耗能框架节点。设计了10个不同参数试件，对其进行拟静力试验，研究不同试验参数下梁柱组合体的裂缝开展情况、滞回特性、预应力筋合力、骨架曲线、钢筋应变等。试验结果表明：相比传统的RC节点，低损伤SCPC节点具有良好的自复位能力和抗震性能，预制构件最大裂缝宽度仅为0.08mm；试验中预应力筋始终保持弹性状态，初始预应力越大、预应力筋四周布置能明显提高SCPC节点的初始刚度和耗能能力，耗能条尺寸为中等型号的软钢阻尼器D1在三种阻尼器中耗能效果最佳；梁中纵向钢筋的应变也随梁端位移的增加而增加，且拉应变值明显大于压应变。此外，通过节点有限元模拟和试验结果的误差分析可得，节点张开弯矩、极限弯矩、初始刚度和开裂后刚度的最大误差均在7%以内，从而验证了有限元模拟方法的精确性，可为低损伤SCPC框架结构的整体抗震分析奠定基础。

Experimental and numerical study on low damage self-centering precast concrete energy dissipated frame connections

In order to improve the seismic performance of traditional prestressed ‘dry connection’ beam-column joints, a low damage self-centering precast concrete (SCPC) energy dissipation frame connection with mild steel damper was proposed.Ten specimens with different parameters were designed, and quasi-static tests were carried out to study the crack development, hysteretic characteristics, resultant force of prestressed post-tensioned (PT) tendons, skeleton curve and reinforcement strain of the connection. The experimental results show that: compared with the traditional RC connection, the low damage SCPC connection has good self-centering capacity and seismic performance, and the maximum crack width of the prefabricated members is only 0.08 mm. The PT tendons always maintain an elastic state in the whole tests. The greater initial PT forces and the tendons arranged on beam corners can significantly improve the initial stiffness and energy dissipation capacity of SCPC connections. The hysteretic damper D1 with medium size of energy dissipation effect has the best energy dissipation capacity among the three dampers. The strain of longitudinal reinforcement in the beam also increases with the increase of beam end displacement, and the tensile strain is significantly greater than the compressive strain. In addition, through the error analysis between numerical simulation results and test results, including the maximum errors of connection opening moment, ultimate moment, initial stiffness and degraded stiffness are within 7%, which verifies the accuracy of the numerical simulation method and lays a foundation for the overall seismic analysis of the low-damage SCPC frame.