Theoretical Analysis And Experimental Study Of Mechanical Performance About CFRP Concrete Structure

This article should carry out multiphase study for some mechanical problems in strengthening concrete structure with carbon fibre. The research mainly begins from the both sides, that is theory and practice, the concerned contents include such aspects as the in-house mechanical property of carbon fibre material, the mechanical characteristic of the bonding interface between carbon fibre and concrete, and the impact on crackgrowth by carbon fibre. Digital image analysis in frequency(DIAF)is applied to experimental study of this field for the first time.Firstly ,some problems existent in the application, of digital image analysis in frequency, to the experimental study of concrete component are analyzed, including such problems as the impact on measuring accuracy by concrete natural surface and sprayed surface and as the impact on measuring accuracy by surface defect, a processing method was presented aiming at rigid body displacement and oversized displacement,the solving method was given for such problems as displacement superposition and mismatching position in series loading,and the measuring accuracy for displacement and deformation is analyzed when digital image analysis in frequency is applied to concrete component experimental studyA module based 3-D shear-lag mode with the parameters of shear surface is set up through the method of statistic failure mode, and the numerical simulation for stretching force performance of CFRP plate is carried out completely and correctly from the aspect of mesomechanics. The toughness of fiber is based upon Monte Carlo method,and the double-parameter Weibull distribution simulation is adopted. Through the experimental study for the frequency domain correlation analysis method of the digital image of carbon fibre sheet material, the correctness of numerical simulation is proved.Interfacial stressσ_p ,τ_p correlative with transverse shear distortion is introduced, and the analytic solution for shear stress and peel normal stress of tri-point curved beam interface of CFRP strengthening concrete with the consideration of distortion effect of transverse shear. Taking this as a base and combining correlation analysis method of digital image frequency domain, photodynamics experimental study is made for displacement field of tri-point curved beam interface of CFRP strengthening concrete, and the relation curve, between shear stress and slippage, of plastering head end of carbon fibre sheet material. As a supplementary study of the mechanical property of CFRP reinforced structure interface, this article also carried out experimental study for interfacial distortion of axial tension aluminium specimen after plastering CFRP.The theory resolution of bearing capacity is found through researching the static equilibrium relation of the fissured cross section of concrete tri-point curved beam with CFRP strengthening by taking the constitutive relation and deformation behavior of concrete and CFRP plate as the base. In the meanwhile,through correlation analysis method of digital image frequency domain and through the experiment study of the displacement field and strain field of the crack tip of load tri-point curved beam of crackled concrete beam with CFRP strengthening, the relation curve between the tension displacement of fissured tip and load is obtained rather accurately.