| CFRP(Carbon Fiber Reinforced Polymer)has competitive advantages on being material of high loaded cables with strengths of light-weight,high-strength,and good resistance on corrosion or fatigue,etc.Comparing with traditional steel cables,CFRP cables have less degradation due to structural weight on carrying capacity and rigidness.Therefore,CFRP cables are applicable over a larger span than steel ones.In addition,life-cycle maintaining cost of CFRP cables can be reduced because of corrosion resistance.Cable produced as assemblies of parallel CFRP plates is a new form of high loaded cables.Using CFRP plates instead of round-section wires as sub-cables takes advantages of larger specific surface area and easier to apply clamping force.Research presented in this thesis is supported by sub-topic of the National High Technology Research and Development Program of China(863 Program)named ‘Study and application of the structural carbon fiber reinforced polymer cable and anchorage',which contains key issues including adjustment factors on carrying capacity of parallel-plate CFRP cable,short-term and long-term properties of CFRP cable and mechanism of the corrugated-plate anchorage.All the research works and conclusions are as follows.(1)Factors that influence the axial tensile carrying capacity of parallel-plate CFRP cable were studied.4 major factors,size effect of cable length,nonuniform slips of plates,anchorage-installation error and nonuniform deflection of plate,were focused on in the study.Theoretical analysis and the Monte Carlo method were used to derive individual and overall adjustment factors for design capacity of axial tension under different requirements of reliability.(2)Curve equation of corrugated anchorage-plate was design.With the use of this corrugated-plate anchorage,initial internal force in CFRP plate forced to deform into corrugated-plate could be analytically solved,and no discontinuity of moment and shear force existed throughout the bond length.Result of axial tensile test proved that potential axial tensile carrying capacity of CFRP-plate cable could reach 90% of the material strength with proper practice of anchoring.Basing on taking limit of max principle stress as the adhesive layer's failure criteria and certain simplifyingassumptions,a simplified calculation model for carrying capacity of corrugated-plate anchorage was founded.Calculation results with this model indicated that enhancement of anchor carrying capacity was proportional to the amplitude of the corrugated-anchorage-shape curve,which was also proved by the experimental results,but magnitude of the enhancement was underestimated.(3)Creep behaviors of CFRP-plate cables with corrugated-plate anchorages were experimentally studied.Experimental data of domestic CFRP plates' creep behaviors was accumulated.Two typical stages in the creep progress were observed,including an initial rapid increment of creep and a following gradually decelerating increment of creep.The conclusion given by previous researches that creep strain of FRP cable was almost proportional to the logarithms of the load time was verified.(4)Axial tensile tests were carried out on parallel-plate CFRP cables with corrugated-plate anchorages.Numerical simulation of the specimens' failure progress was implemented using finite element method.The mechanisms behind decrease on anchor carrying capacity and difference among failure progresses of parallel plates were revealed.In summary,this thesis has made some progress on anchorage design,carrying capacity design and long-term behavior of domestic CFRP-plate cables.The presented result could provide theoretical and data support for the application of CFRP high loaded cables. |
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