Analysis On Dynamic Response And Crack Propagation Of Reinforced Concrete Beams With Cracks Under Impact Load

Concrete structures often cause serious damage after being subjected to impact loads.Especially after the "9.11 Event",the nonlinear dynamic behavior of structures under impact load has become the focus of scholars and engineers.At present,most researches on reinforced concrete beams under impact load are complete reinforced concrete beams,but in reality,concrete structures often work with cracks.Therefore,the study on the dynamic response and crack propagation of reinforced concrete beams with cracks under impact load is more in line with the actual situation.In this paper,the reinforced concrete beam with cracks is taken as the research object,and the finite element software ABAQUS is used to study the dynamic response and crack propagation of the reinforced concrete beam with cracks under the impact load.The main work and conclusions are as follows:(1)The finite element model of reinforced concrete beam with crack under impact load is established.The maximum principal stress criterion and failure energy criterion are used to describe the mechanical behavior of concrete under tension.The relationship of energy conversion and hourglass energy control are used to ensure the effectiveness of the finite element calculation results.(2)By changing the impact quality,impact speed,reinforcement ratio,initial crack length and crack offset position,the dynamic response of reinforced concrete beams with cracks under impact load is analyzed.The results of parameter analysis show that the impact quality,impact speed,reinforcement ratio,initial crack length and crack offset position are the main parameters affecting the dynamic response of reinforced concrete beams with cracks under impact load.(3)In view of the fact that ABAQUS can not directly extract crack propagation path,crack propagation rate and other relevant parameters,this paper has compiled crack information processing program based on Matlab.The program can calculate and draw the corresponding curve through the effective data derived from ABAQUS.The result of the program is compared with that of ABAQUS,which shows that the program can reduce the crack propagation process well.(4)By changing the impact quality,impact speed,reinforcement ratio,initial crack length and crack offset distance,the parameter analysis is conducted on the crack propagation of reinforced concrete beams with cracks under impact load.The results of parameter analysis show that the impact quality,impact speed,reinforcement ratio,initial crack length and crack offset distance are the main parameters that affect the crack propagation rule of reinforced concrete beams with cracks under impact load.