Dynamic Response Analysis Of Reinforced Concrete Column Under Lateral Impact

The destruction of some partial essential components in structures often causes the component failure, even the entire structure under impact loads such as explosive and impulsive loads. Studying the anti-impact property of component is the foundation of structural design for disaster prevention and resisting progressive collapse. RC columns are the important load-bearing components in frame construction. Once component occurred serious damage,it possibly results in the destruction of the entire building. Study of the anti-impact properties of the RC columns under impact loads has the practical significance and applied value. The performance of failure mode, bearing capacity and deformation characteristics of RC column are researched through experiment and finite element analysis under lateral impact, and the effects of reinforcement ratio, axial compression ratio, cross section dimension, concrete strength and stirrup spacing on the performance of the anti-impact property of RC column are analyzed.Experimental study: the MTS which is pseudo-dynamic servo-hydraulic loading system is used in impact loading, and the test platform is designed independently. The actual stress situation of frame column is simulated through the imposition of constraints moment. Eight RC column specimens (using 1/2 scale) are experimented considering the different ratio of reinforcement and axial compression ratio. The steel and concrete strains, deflection, axial force and support restraint situation are measured and analyzed. the dynamic response and the failure mode of RC columns is obtained under the impact load; with the same axial compression ratio, raising longitudinal reinforcement ratio can enhance ultimate bearing capacity and the deformation capacity of columns, the greater loading rate the greater the increase amplitude; with the same ratio of longitudinal reinforcement, raising axial compression ratio can enhance ultimate bearing capacity. The loading rate has a little effect on ultimate bearing capacity, but it will reduce the deformation ability of column.Finite element analysis: based on the finite element analysis software ANSYS, dynamic responses of RC columns under lateral impact are analyzed. Parametric studies are adopted to investigate the influence of cross section dimension, concrete strength, longitudinal and transverse reinforcement ratio on the dynamic responses of RC columns. The influence of longitudinal reinforcement ratio and cross section dimension could reduce the mid-span dynamic drift, but the influence of stirrup ratio does not have obvious effect on the dynamic response.