带键槽梁底筋锚入式预制梁柱连接塑性铰长度研究

针对混凝土构件在反复荷载作用下的受力特点，提出了拉-压综合塑性铰长度概念；通过低周反复荷载试验，研究了带键槽梁底筋锚入式预制梁柱连接的塑性铰特点，并得出了拉-压综合塑性铰长度的试验结果；以Panagiotakos模型为基础，提出了考虑预制形式、混凝土局部横向约束和配筋率影响的修正塑性铰长度模型。结果表明：拉-压综合塑性铰长度可综合反映反复荷载作用下塑性铰的损伤情况；带键槽梁底筋锚入式预制梁柱连接塑性铰形态与现浇对比试件略有差别；修正的塑性铰长度模型可以较好地预测该类梁柱连接拉-压综合塑性铰长度。

Plastic hinge length of precast beam-column connections with U-shaped shells and anchored bottom longitudinal bars in beams

Considering the mechanical characteristics of concrete components under low-cyclic loadings, the definition of tension-compression plastic hinge length was put forward. Through low-cyclic loading tests, the characteristics of plastic hinges of new precast beam-column connections with U-shaped shells and anchored bottom longitudinal bars in beams were studied, and experimental results of tension-compression plastic hinge length were obtained. Based on the Panagiotakos model, a modified plastic hinge length model was proposed, involving local confinement of concrete, prefabricating details and reinforcement ratios. The results show that the tension-compression plastic hinge length can reflect the damage of plastic hinge regions under low-cyclic loadings. The plastic hinges of precast beam-column connections with U-shaped shells and anchored bottom longitudinal bars in beams have some minor difference from monolithic connections. The modified plastic hinge length model can be used to well evaluate the tension-compression plastic hinge length of this connection.