Meso Analysis Of Damage Mechanism Of Carbon Fiber Reinforced Concrete

Carbon fiber is a high-elasticity,high-strength material.Incorporating carbon fiber in concrete can significantly improve the tensile strength and crack resistance and toughness of concrete.In recent years,scholars have conducted a large number of experimental studies on carbon fiber concrete,but There are few studies at the meso level,and the properties of each material component at meso level will directly affect the damage and damage process of carbon fiber concrete.Therefore,at this meso level,the macroscopic mechanical properties and damage mechanism of carbon fiber concrete are numerically simulated.the study.The research content is as follows:The equivalent elastic modulus of carbon fiber concrete was calculated by Mori-Tanaka theory and finite element numerical simulation,and the effects of different carbon fiber content,carbon fiber length-to-diameter ratio,carbon fiber length,and carbon fiber shape on the equivalent elastic modulus of carbon fiber concrete were investigated.The results show that the shape,length-diameter ratio and length of carbon fiber have very little effect on the equivalent elastic modulus of carbon fiber concrete,while the carbon fiber volume fraction has the greatest effect on the equivalent elastic modulus of carbon fiber concrete.And the theoretical analytical solution is compared with the finite element method and the test results to verify the reliability of the results.A Python program for embedding zero-thickness bonding elements inside the mortar and the mortar-carbon fiber interface and the mortar-aggregate interface was compiled by ourselves,and the numerical simulation of the uniaxial compression process of carbon fiber concrete members under five different carbon fiber contents The model was verified,and the simulation results of compressive strength were compared with the test results.The comparison results are in good agreement,with a maximum error of 3.73%,which proves the accuracy of the selected model of bond cracks.After studying the network dependence,a mesoscopic finite element model of carbon fiber concrete was established based on the established bond crack model to simulate different carbon fiber volume ratios,carbon fiber length,fracture energy of interface transition zone,carbon fiber aggregate distribution,mortar matrix The effect of elastic modulus on the tensile,compressive properties and damage damage process of carbon fiber concrete.The results show that the length of carbon fiber,interface fracture energy and mortar elastic modulus have little effect on the tensile strength of carbon fiber concrete,while the amount of carbon fiber on the resistance of carbon fiber concrete The tensile and compressive properties have the greatest impact,and the greatest when the dosage reaches 0.24%.In addition,the carbon fiber in the component plays a role in spreading the mortar tension and polymerization to restrict the crack propagation during the crack development stage of the concrete and makes the whole specimen difficult to penetrate,preventing the stress from being transmitted to other units,thus playing the role of crack resistance and toughening.The four-point bending simulation of the carbon fiber concrete beam reveals the destruction law of the carbon fiber concrete beam.Finally,the damage and failure process simulation of carbon fiber reinforced concrete members and four-point bending beams under load and temperature coupling is carried out.The results show that both carbon fiber reinforced concrete members and carbon fiber reinforced concrete beams have larger crack propagation and more cracks when considering the load temperature coupling effect It is concluded that the additional stress generated by the temperature difference will promote the crack propagation.