Axial Impact Load of a Concrete-Filled Steel Tubular Member with Axial Compression Considering the Creep Effect

Abstract

The dynamic loads acting on concrete-filled steel tubular members under axial impacts by rigid bodies were studied herein by FEM. The whole impact process was simulated and the time history of the impact load was obtained. The effects of eight factors on the axial impact load were studied; these factors were the impact speed, mass ratio, axial pressure ratio, steel ratio, slenderness ratio, concrete strength, impact position, and boundary conditions. Besides this, the effects of concrete creep on the impact load were also considered by changing the material parameters of the concrete. The results show that axial impact load changes with time as a triangle. The peak value of impact load increases and the impact resistance improves with the growth of the axial pressure ratio, steel ratio, slenderness ratio, and concrete strength after creep occurs. As the eccentricity of the axial impact acting on a concrete-filled steel tubular member increases, the peak value of the impact load decreases. The enhancement of constraints at both ends of the member can improve the impact resistance. The creep reduction coefficients for the peak axial impact load of a concrete-filled steel tubular member under axial compression and considering the creep effect over 6 months and 30 years are 0.60 and 0.55, respectively. A calculation formula for the peak value of impact load was suggested based on the existing formula, and its accuracy was proved by finite element calculation in this study.

Optimal Design of Seismic Resistant RC Columns

“…Hysteric dissipation of energy converts the kinetic energy of motion into heat. Accordingly, each member selected to deform inelastically must be suitably designed and detailed, so as to guarantee the energy dissipation in the member by means of stable, wide, and compact hysteretic loops, over the range of displacement amplitudes expected in the seismic design situation [7][8][9].…”

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Special Issue: “Ceramics and Construction Materials”

“…Several published articles are focused on binders and concrete [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ], so showing the great scientific interest associated to these materials. Attention has been reserved to the low-carbon cements, i.e., cementing binders produced with low greenhouse emissions [ 1 , 2 ].…”

“…The improvement in the mechanical properties of mortars is related both to the size reduction of bubbles with increasing their concentration in water and the increased probability of cement particles to hydrate when impacting bubbles with reduced sizes. Papers [ 4 , 5 , 6 , 7 ] deal with reinforced or not-reinforced concrete mixes and investigate different aspects of their performances. A finite element model is used in [ 4 ] to simulate the dynamic responses of a concrete-filled tubular steel member under the combined action of axial compression, creep and axial impact.…”

“…Papers [ 4 , 5 , 6 , 7 ] deal with reinforced or not-reinforced concrete mixes and investigate different aspects of their performances. A finite element model is used in [ 4 ] to simulate the dynamic responses of a concrete-filled tubular steel member under the combined action of axial compression, creep and axial impact. A calculation formula for the peak impact load under axial compression considering creep is proposed, which can help in the design of the impact resistance of this kind of structure.…”