| The CFRP ring beam method has been widely used for the reinforcement of reinforced concrete(RC)columns,but the CFRP reinforced columns located in the ground floor buildings,parking lots and bridge piers are vulnerable to side effects such as vehicle loads.The impact action may cause great damage to the carbon fiber cloth attached to the reinforced concrete column,and even lead to the serious consequences of the structure collapse.The current design standard does not consider this safety hazard,and it is unknown that the remaining CFRP reinforced column has not been completely destroyed.Whether the bearing capacity can still meet the structural bearing requirements.Therefore,this paper adopts the simulation analysis method to establish the finite element model of the CFRP ring-bundle-reinforced RC cylinder-rammer system that can consider material nonlinearity and contact nonlinearity,and accurately simulates the transient dynamics of the reinforced column when the vehicle is impacted by a vehicle at low speed.,And consider the impact of different parameters on the impact mechanical behavior of the reinforced column and the residual bearing capacity of the reinforced column after the impact is not completely destroyed,which provides a quantitative basis for further improving and enhancing the impact resistance design of the reinforced column.The main research contents of this paper are:First,complete the dynamic load impact and static axial compression tests on the CFRP-reinforced concrete column,and simulate the mechanical behavior of the CFRP-reinforced concrete column during the full impact process through the LS-DYNA explicit finite element model.Furthermore,the ANSYS implicit finite element model is used to simulate the axial compression test process of the impacted damaged column.The two-stage finite element calculation results are in good agreement with the experimental results,which verifies the accuracy of the finite element simulation model in this paper.Subsequently,the finite element explicit model of the CFRP-reinforced reinforced concrete column-rammer system was used to study the mechanical behavior of the CFRP-reinforced RC column during vehicle impact,including the impact speed,the number of CFRP reinforcement layers,the vehicle mass,the axial compression ratio,and the impact eccentricity.The effect of 7 parameters including distance,concrete strength and impact height has been systematically analyzed.The study found that the impact speed,concrete strength,number of CFRP reinforcement layers and impact eccentricity have significant effects on the dynamic response and damage degree of the CFRP reinforced column after being impacted by a vehicle;within the scope of this paper,the impact of axial compression ratio is small;while impact The height has no obvious effect;when the initial kinetic energy of impact is the same,the dynamic response of the specimen is more sensitive to the change of impact mass,and the damage degree of the specimen is more sensitive to the change of impact velocity.Lastly,using the explicit-implicit continuous solution method as the bridge,the finite element implicit model of the reinforced concrete column strengthened by the CFRP damaged by the impact further explores the residual axial compression bearing capacity of the damaged column after the vehicle impact.And systematically quantitatively analyze and compare the effects of the above seven parameters.The study found that as the impact damage increases,the remaining bearing capacity of the specimen decreases;for the remaining bearing capacity of the CFRP-reinforced column after being hit by a vehicle,the impact speed,the number of CFRP-reinforced layers,the concrete strength and the axial compression ratio have significant effects;The eccentricity has a small effect;while the impact height has no obvious impact;when the initial kinetic energy of the impact is the same,the bearing capacity of the damaged column is relatively high after the impact mass increases,and the ductility is relatively good. |
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