碳纤维增强树脂复合材料(CFRP)拉挤板材的楔形-挤压锚固机制

Wedge-extrusion anchorage mechanism of pultruded CFRP plate

碳纤维增强树脂复合材料(CFRP)板材的可靠锚固是影响桥梁结构预应力加固应用的关键问题。本文提出一种采用化学黏结及物理挤压为受力模式的CFRP板材楔形挤压锚固系统,该锚固系统通过楔形锚固树脂与CFRP板材的挤压与黏结作用传递外部荷载。采用力学分析及有限元模拟研究该锚固系统内荷载传递方式与锚固机制,通过拉伸试验获得锚固系统的锚固效率及应力分布。结果表明:Tc和T1两种锚固树脂胶黏剂锚固CFRP板材都具有较高的锚固承载力,且极限锚固承载力随锚固树脂韧性增大而增大;静载作用下锚固系统的破坏方式为CFRP板材爆裂破坏,与力学分析及有限元模拟结果相吻合;循环荷载下锚具内应力分布均匀,无明显应力集中。

The reliable anchoring of carbon fiber reinforced polymer composite(CFRP)plates is a key to the prestressing reinforcement application of the bridge structures.In this paper,by using a new type of wedge-extrusion adhesive type anchorage system of pultruded CFRP is put forward,in which chemical bonding and physical extrusion is used as the loading mode.The mechanical analysis and the finite element simulation are applied to study the load transfer mode and anchoring mechanism of this anchorage system.The tensile tests of the anchorage system are conducted to obtain the ultimate bearing capacity and stress distribution.Results show that both the anchorage system adopting the TC and that of T1 resin adhesives for anchoring the CFRP plate have high anchorage bearing capacity.The ultimate anchorage bearing capacity of anchored resin increases with its ductility.Under the static load,the fracture mode of CFRP plate is CFRP burst,which is consistent with the results of mechanical analysis and the finite element simulation.Under the cyclic loading,the stress distribute uniformly in the anchor without obvious stress concentration.