基于复合材料预紧力齿连接和螺纹连接的组合接头极限承载性能研究

Study on the Ultimate Load-carrying Capacity of the Composite Joint based on Pre-tightened Teeth and Threaded

复合材料预紧力齿连接技术(PTTC)是一种承载效率较高的连接技术,可用于解决复合材料拼装式结构的连接问题。此种连接方式虽然能提升节点的荷载传递效率,但在高承载下的破坏模式为齿的脆性剪切,延性性能较差。提出了一种可应用于拼装式复合材料杆件的基于PTTC连接技术和螺纹连接的组合接头,通过ANSYS进行了压缩荷载下的极限承载性能研究,分别采用力与位移加载的方式进行了计算,明确了接头的破坏模式、获得了荷载-位移曲线。研究发现:在一定玻璃纤维增强复合材料(GFRP)杆件长度下,破坏模式先后表现为杆件屈曲失稳、金属套筒塑性破坏以及GFRP管受压劈裂等,均避免了纤维增强复合材料(FRP)齿的脆性剪切破坏。此外,位移加载条件下延性系数有较大提高,组合接头延性性能较好,计算结果与工程实际应用更贴合。

Composite Pre-tightened Teeth Connection(PTTC) is a new connection technology with higher load-carrying efficiency,can be used to solve the connection problem of assembled structure made by fiber reinforced composite material(FRP).Although this connection method can improve the load transfer efficiency of the node,ductility of joint is poor.The failure mode,under high load,is the brittle shear of the tooth.This paper proposed a composite joint based on PTTC and threaded connection technology that can be applied to assembled composite rods,the ultimate load-carrying capacity under compression load is studied through ANSYS.The calculations are carried out by means of force-control and displacementcontrol respectively,the failure mode of the joint is clarified,the load-displacement curve is obtained.The study found that under a certain length of GFRP member,the failure modes are successively manifested as member buckling instability,metal tube plastic failure,and GFRP tube compression fracture,etc.,all of which avoid the brittle shear failure of FRP teeth.In addition,the ductility coefficient increased efficiently under the displacement loading condition,the ductility performance of the composite joint is better,and the calculation results are more suitable for practical engineering applications.