Dynamic Response Of Reinforced Concrete Columns Under Impact Loading And Analysis Of Bonded Steel Reinforcement

Reinforced concrete column is an important force component,and its performance under impact,explosion and other dynamic loads is worth in-depth study.In order to correctly understand the performance and performance of reinforced concrete columns under lateral impact loads,the effect of bonded steel reinforcement methods on the dynamic characteristics and impact resistance of reinforced concrete columns was studied,with a view to improving the impact resistance design and protection of reinforced concrete columns.For certain reference,this paper uses ANSYS/LS-DYNA software to simulate and analyze reinforced concrete columns and bonded steel columns.The main research content is as follows:(1)According to the “Code for Design of Concrete Structures”,a finite element analysis model of reinforced concrete columns was designed to study the impact position,column height,reinforcement ratio of longitudinal reinforcement,concrete strength,impact contact area,and axis under lateral impact loads.The influences of pressure ratio,impact velocity and impact mass on impact response and displacement response of reinforced concrete columns.The analysis results show that the impact force response and displacement response of reinforced concrete columns are mainly affected by the impact energy and the stiffness of the column itself.In addition,the impact contact area has a significant impact on the peak impact force;the column displacement response Lateral displacement and vertical displacement are more consistent when affected by the above factors.We can weaken the RC column by increasing the reinforcement ratio of the longitudinal reinforcement,increasing the axial pressure within a certain range,and reducing the impact energy received by the cylinder.Displacement response at lateral impact loads.(2)In the analysis of bonded steel reinforcement methods,two stick y steel reinforcement column models were designed on the basis of the aforementioned study of reinforced concrete columns(respectively,the overall stick steel reinforcement method on the side of the sticky steel plate.,only the height of the cross-section of the cylindrical section of the sticky steel plate reinforcement method).Firstly,the dynamic characteristics of the two types of reinforced columns were analyzed and compared with the unreinforced reinforced concrete columns.The comparison results show that: the stick steel reinforcement has different effects on the frequency and mode shape of reinforced concrete columns: two different reinforcements Compared with the method,the integrated steel-reinforced method has a great influence on the frequency of the column members,while the local steel-bonding method has a great influence on the vibration performance of the column members.(3)The parameter analysis of the dynamic characteristics of the reinforced columns reinforced by the integrated reinforcement method was analyzed.The influence of the thickness of the bonded steel,the height of the columns,the cross-sectional dimensions,and the supporting form on the natural vibration frequency of the reinforced columns was analyzed.The analysis results showed that: Among the several factors,the influence of column height is the most significant.With the increase of the column height,the natural frequency of the members of each order decreases and tends to be concentrated.Therefore,the higher o rder modes of the reinforced column should be considered when the column height is large.The support form of the component has an influence on the natural vibration frequency of the reinforced column.The influence of the cross-section size on the natural vibration frequency of the reinforced column is generally small.However,in the studied bond steel thickness range,the natural vibration frequency of the bond steel thickness to the reinforced column The effect is not obvious.(4)Analyze the influence of the two types of sticking steel reinforcement and sticking steel thickness on the impact resistance of reinforced concrete columns.The analysis results show that the integral reinforcement and partial reinforcement of two kinds of steel reinforcement methods involved in the dynamic characteristics analysis can effectively inhibit the local and global lateral deformation of the reinforced concrete columns when they are subjected to impact loads,and reduce the impact of the impact.The stress that the cylinder bears reduces the occurrence of concrete peeling and damage after the cylinder impact.Among them,for the improvement of cylinder damage degree,the use of integrated steel reinforcement can effectively reduce the overall degree of damage of the cylinder and reduce the damage range of the cylinder;while the local sticking steel reinforcement method is harmful to the cylinder.The improvement of the extent and extent of damage is not obvious;in the study of the effect of bond steel thickness on the impact resistance of reinforced concrete columns,it was found that when the impact load is constant,the local thickness and the overall lateral displacement of the bonded steel to the cylinder The inhibitory effect and column damage improvement showed a trend of increasing first and then decreasing.The analysis results show that the steel-bonded reinforcement is a reinforcement method that can effectively improve the damage of reinforced concrete columns and columns,suppress the lateral deformation of the columns,and thus improve the impact resistance of reinforced concrete columns.It should give priority to the use of overall reinforcement.