Design And Performance Test Study Of Anchorage For Prestressed CFRP Plate

CFRP has many excellent properties,such as light weight,high strength,fatigue resistance,corrosion resistance.It is often used in the field of structural reinforcement.The traditional bonded CFRP reinforcement method has the phenomena of stress lag and low utilization rate of material strength.Prestressed CFRP reinforcement can effectively solve these problems,but efficient and reliable anchorage system is the premise of successful application of prestressing force.Therefore,A new type of mechanical clamping anchor was presented,which is suitable for commercial CFRP sheets with different width and thickness.The main research contents are as follows:(1)Based on the complex structure,insufficient anchoring force and less research on fatigue performance of existing prestressing CFRP anchorage,a new design concept is proposed to optimize the structure and interface performance of wedge-shaped splint.The inclination range of wedge-shaped structure was predicted.A more accurate and easy-to-control anchorage pre-tightening method was proposed.(2)The numerical simulation of the anchorage system is carried out,and the stress distribution of CFRP plate in the anchorage and the influence of design parameters on it are analyzed.The results show the conclusion that the bending deformation of the anchor plate under the combined action of pre-tightening load and tension load is lateral,the compressive stress of the splint diffuses at 45 degrees,the compressive stress and the principal tensile stress of the CFRP plate distribute inversely,and the peak shear stress appears at the steepest position of the change of the compressive stress grad The thickness of anchor plate and splint has little influence on the stress distribution,which can not be neglected for safety reasons.Pre-tightening load,friction coefficient of splint interface,length of splint angle and width of CFRP plate have great influence on stress distribution.Sensitivity analysis also shows that these parameters belong to key design parameters.(3)The anchorage capacity and stability of anchorage are verified by static tension and fatigue tests respectively.The tests results show that the typical failure modes of anchorage include sliding and rupture of CFRP plate.The anchorage capacity of anchor depends on the structure of clamp,bolt pretension load and friction coefficient of the interface between clamp and CFRP plate.The anchorage efficiency of the designed anchor is over 90% with high strength utilization ratio of CFRP material,stable and reliable anchorage system.Finite element analysis and experimental verified the anchor designed in this paper was novel in concept,reasonable in structure,economical and applicable,has remarkable anchorage capacity.It plays a certain role in promoting the development of pre-stressed CFRP anchorage and has reference value.