Abstract：8 specimens of circular-in-square concrete filled doubleskin steel tubular (CFDST) with large hollow ratio were tested under the lateral impactThe impact process, failure modes of the specimens, time history of the impact force, lateral deformations and longitudinal strains were analyzed based on the experimental resultsThe effects of the impact height, boundary condition and axial load ratio on the dynamic response of circularinsquare CFDST composite components under lateral impact were consideredThe test results show that obvious local deformation at the impact location of the circularinsquare CFDST composite components with the hollow ratio of 069 can be observed and the global bending deformation is not significantWithin the experimental parameters scope, with the increase of impact height, local deformation at the impact location, residual lateral deformation at midspan and the impact duration time increase linearlyBoundary condition has a significant effect on the residual lateral deformation at the midspan, the plateau values of the impact force and the impact duration timeAxial load ratio is an important factor affecting the dynamic response of specimensWith the increase of the axial load ratio, the plateau values of the impact force gradually shorten and disappear, the deformation speed of lateral deformation at midspan becomes faster and the impact process also becomes more faster.
