变形灌浆套筒连接性能试验研究及有限元分析

为降低预制装配混凝土结构中的钢筋连接成本，采用低合金无缝钢管，通过冷滚压工艺制作了一种新型变形灌浆套筒。通过对9个钢筋连接接头试件进行单调轴向拉伸试验及有限元分析，研究了套筒的连接性能、工作机理及设计方法。结果表明，钢筋锚固长度取6.9~7.5倍连接钢筋直径时，该变型灌浆套筒连接接头的单向拉伸强度能够满足1.1倍钢筋抗拉强度标准值要求；套筒的内腔结构影响套筒的应变分布及约束机理，内壁环肋处的接触压力造成套筒变形段筒壁应力不均匀分布；文中所采用的有限元模型可有效地模拟套筒与灌浆料以及灌浆料与连接钢筋间的相互作用；探讨了变形灌浆套筒的设计方法，并应用该方法设计了不同直径的HRB400级钢筋连接用套筒，其钢筋连接接头满足规范JGJ 107-2010对Ⅰ级接头的强度和变形性能要求。

Experimental study and finite element analysis on behavior of deformed gout-filled pipe splice

To reduce the cost of rebars splicing used in precast connections, a novel deformed grouted sleeve was developed using seamless steel pipes through the cold rolled pressing technology. Based on the incremental tension test of nine splice specimens and the finite element analysis, the behavior, working mechanism and design method of the new splice were studied. It is shown that the proposed splice is capable of developing 110% of the specified ultimate strength of the spliced bar with an embedded length of 6.9-7.5 times the bar diameter. The inner cavity structure of the sleeve provides significant influence on the strain distribution and confining mechanism of the sleeve. The contact pressures on the inner ribs make the stresses in the deformed part of the sleeve not uniformly distributed. The finite element model illustrated in this paper can simulate the interaction effect between the sleeve and grout, and also between the spliced bars and the grout properly．A design method for the grouted sleeve is proposed. Using this method, different sleeves for splicing deformed bars with different diameters were designed and inspected. The results meet the regulations on the strength and deformation for classⅠsplice specified in JGJ 107—2010.