装配式混凝土预埋型钢铰接梁力学性能有限元分析

Finite element analysis of mechanical properties of prefabricated concrete hinged beam with embedded section steel

为使装配式混凝土梁-梁实现铰接连接,提出一种基于预埋型钢的装配式混凝土铰接梁。结合预埋型钢设计方法,分别设计5个基于预埋槽钢和5个基于预埋角钢分析模型,并采用校正的有限元法对其力学性能进行研究。结果表明:各模型荷载位移曲线均包括弹性、弹塑性和破坏阶段;基于预埋角钢与基于预埋槽钢的铰接梁最大荷载值仅相差1.04%。当预埋型钢面积不足时,出现预埋型钢破坏、混凝土梁与端部钢板分离、端部纵向钢筋屈曲、荷载-位移曲线末端承载力下降等现象。当预埋型钢面积满足要求时,装配式混凝土铰接梁与现浇混凝土铰接梁的损伤区域和损伤模式基本相同,端部预埋方式具有足够承载力。由此可知,预埋型钢面积是影响铰接梁破坏模式以及保证连接可靠的关键性因素。所提出的铰接梁具有端部连接可靠和施工简单等特点,可实现预期的力学性能。

In order to realize reliable hinged connection between prefabricated concrete beams,a prefabricated concrete hinged beam based on embedded section steel was proposed.Combined with the design method of embedded section steel,five analysis models based on embedded channel steel and five analysis models based on embedded angle steel were designed respectively,and their mechanical properties were studied by corrected finite element method.The results showed that the load displacement curves mainly contain elastic stage,elastic plastic stage and failure stage,and the maximum load difference between hinged beams based on embedded angle steel and embedded channel steel was 1.04%.When there is lack of area for embedded steels,the failure of embedded steels,separation between concrete beam and endplate,longitudinal reinforcement buckling and decrease of bearing capacity of load-displacement curve will appear in the prefabricated concrete beams.In addition,the damage mode and damage area between prefabricated concrete beams and cast-in-siteconcrete beams were basically same while the embedded steels have a sufficiently section area,and the prefabricated concrete beam can have enough bearing capacity.It can be seen that the area of embedded steel was a key factor affecting the failure mode of the hinged beam and ensuring the reliability of the connection.The proposed hinged beam has the characteristics of reliable end connection and simple construction,and can achieve the expected mechanical properties.