基于非局部增强塑性损伤微平面模型的装配式梁柱节点力学性能研究

Study on mechanical properties of fabricated beam-column joints based on nonlocal enhanced plasticity-damage microplane model

装配式结构梁柱节点是影响结构力学性能的关键部位,为深入全面地探究其非线性力学行为,基于非局部增强塑性损伤微平面模型,运用ANSYS有限元程序,考虑新旧混凝土结合面等构造措施,建立精细化有限元计算模型,以相关试验为基础,比较验证了所建有限元模型的可靠性。并以后浇区混凝土强度等级、轴压比、梁上部纵筋配筋率为参数,考察其对装配式节点承载力及延性的影响。结果表明:节点承载力随后浇区混凝土强度等级、轴压比、梁上部纵筋配筋率的增大而增大;节点延性随后浇区混凝土强度等级、梁上部纵筋配筋率的增大而增大,轴压比则对其影响较小。为装配式结构梁柱节点的设计和应用提供了理论依据和参考。

Beam-column joints of the fabricated structure are the key parts that affect the mechanical properties of the structure.In order to thoroughly and comprehensively explore its nonlinear mechanical behavior,it establishes a refined finite element calculation model based on the nonlocal enhanced plastic damage microplane model,using the ANSYS finite element program,considering construction measure such as the new-old combination surfaces of concrete.Based on the relevant tests,the reliability of the finite element model is compared and verified.The influence of concrete strength grade,axial compression ratio and longitudinal reinforcement ratio on the bearing capacity and ductility of prefabricated joints was investigated.The results show that the bearing capacity of the joint increases with the increase of the concrete strength grade in the cast-in-place,axial compression ratio and the longitudinal reinforcement ratio in the top of the beam.The ductility of the joint increases with the increase of the concrete strength grade and the longitudinal reinforcement ratio in the top of the beam,and the axial compression ratio has little effect on it.And it provides theoretical basis and reference for the design and application of beam-column joints in fabricated structures.