Study On Residual Bearing Capacity Of RC Columns Strengthened By CFRP Ring Circumference Under Low Velocity Impact

The RC column is the main structural member of the building.Once a strong impact occurs,the entire building will undergo local damage or even collapse.In fact,when the initial kinetic energy of the impact is large,the building structure may not be suitable for continued loading due to severe damage to the RC column;when the initial kinetic energy of the impact is small,although the RC column has a certain degree of damage,the entire building structure can also be continue to carry.Understanding the impact resistance of the RC column and the residual bearing capacity of the RC column after being impacted can not only avoid unnecessary waste,but also reduce safety risks and have great economic value.In this paper,ANSYS/LS-DYNA is used to establish the impact model of CFRP hoop reinforcement to reinforce the RC column and ram.The impact process and dynamic response of the RC column are analyzed.The initial kinetic energy of the ram and CFRP reinforcement layer are studied.The impact of the initial shape of the hammer on the impact resistance of the reinforced RC column.After the explicit dynamic analysis of the reinforced RC column,the residual bearing capacity of the damaged column was analyzed using ANSYS,and the initial kinetic energy of the hammer,the number of CFRP reinforcement layers and the initial shape of the hammer were studied.The impact of the remaining bearing capacity.The results of finite element calculations show that:(1)The larger the initial kinetic energy of the hammer,the greater the contact force of the RC column,the greater the degree of destruction of concrete and CFRP;(2)The contact of the RC column with the increase of the number of CFRP layers.The force extreme increases,the internal energy absorbed decreases,and the damage degree of concrete and CFRP also decreases;(3)When the initial kinetic energy of the hammer is the same,the impact of the ball hammer on the RC column More severe;(4)The residual bearing capacity of the damaged column is significantly lower than that of the unimpacted column,and the greater the initial kinetic energy of the hammer,the greater the reduction in the ultimate bearing capacity of the damaged column;(5)The more layers of CFRP reinforcement,The reduction of the residual bearing capacity of the damaged column is smaller;(6)Under the same initial kinetic energy,the residual bearing capacity of a damaged column impacted by a spherical hammer is lower than that of adamaged column impacted by a cylindrical hammer.