Experimental Investigation On The Mechanical Properties And Damage Monitoring Of A Novel Arcuate Cone Bond-type Anchorage For CFRP Tendons

Carbon fiber reinforced polymer(CFRP)can fully exert its tensile strength as tendons,but as an anisotropic materials,conventional anchorage systems cannot be applied to CFRP tendons.Bond-type anchorage can protect the surface of CFRP tendons,but there is still a phenomenon of stress concentration in the anchorage area.On the one hand,the bonded anchorage has a variety of failure modes,and the damage mechanism is also difficult to analyze.On the other hand,their failure occurs instantaneously,which is difficult to predict.Therefore,acoustic emission(AE)technology is introduced as a non-destructive monitoring method to analyze the failure mechanism and predict failure.The main research contents and results are as follows:A new kind of arcuate cone bond-type anchorage for CFRP tendons was designed.The stress distribution curves,load-slip curves and failure modes of anchorages are obtained by tension test of a group of anchors with different parameters.According to the test results,the influence of anchorage types,inclination angles and radius of arc on anchorage performance is analyzed.The results show that ultimate anchoring capacity is directly proportional to the slip between barrel and grout.The ultimate anchoring capacity of arcuate cone bonded anchors is larger than that of inner cone anchors,and the phenomenon of stress concentration is effectively alleviated.The damage process of inner-cone and arcuate-cone anchorage under tension load is monitored using AE technology.The complex failure modes of bonded anchorage are identified through AE signal classification and RA-AF analysis.The correlation analysis of the AE cumulative energy and load significantly contributes to the damage evolution of the anchorage;the damage to the bonded anchorage is divided into three stages.Time domain analysis of damage parameters and b-values verifies the damage evolution and provides a destruction warning.The failure mechanism of the cone-type bonded anchorage proposed in this research is consistent with the tension test data and multi-proxy analysis of the AE signal.