Creep-Effected Dynamic Response of a Concrete-Filled Steel Tubular Member in Axial Compression and Impact Load

The finite element model of a tubular member under the combined action of axial compression, creep, and axial impact was constructed with the numerical analysis software, to evaluate the core concrete creep effect on the dynamic responses of a steel tubular member in axial compression. In the model, the creep effect of core concrete of different age is equivalent to the change of its elastic modulus. Then, the dynamic responses of a tubular member in axial compression and impact were simulated considering the creep effect, time-history curves of impact load, contact time, axial deformation, stress and strain were plotted, and the effect of creep on them was discussed. The impact load peak decreases with the development of the core concrete creep, and the most is about 51%; the contact time and axial deformation increase; the concrete stress decreases, but the concrete strain increases greatly. The minimum and maximum principal concrete strains after 30 years exceeded those after 28 days by 6.35 and 8.6 times, respectively. The core concrete creep has a less effects on the stress and strain of the steel tube. The fruits provide a scientific help for the impact resistance design of a concrete-filled steel tubular member in axial compression.