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8 Response of UHPCC-FST Subjected to Low-Velocity Impact
transverse impacts. It was shown that the concrete filled steel square beams demonstrate significant reduction in transverse failure deflection and much superior energy
absorption capacity compared to the hollow steel square beams. Remennikov et al.
(2011) experimentally and numerically (using the program LS-DYNA) investigated
the impact behavior of square hollow section tubes filled with the rigid polyurethane
foam (RPF) and the normal weight concrete (compressive strength of 41 MPa). It
was indicated that the square concrete-filled tube has the highest impact resistance
and energy absorption capacity, followed by the square RPF-filled tube and then
the square hollow tube. Deng et al. (2012) conducted drop hammer impact test on
simply supported circular CFST, circular post-tensioned concrete-filled steel tube
(PTCFST) and circular steel fiber reinforced concrete-filled steel tube (FRCFST)
specimens with the compressive strength of concrete less than 60 MPa. It was derived
that, the PTCFST and the FRCFST specimens demonstrate superior impact resistance than the regular CFST specimens, and using the pre-stressed strands and steel
fibers can effectively restrain the cracks in the tension area of the core concrete.
Yousuf et al. (2012) performed an experimental study to investigate the behavior
of hollow and concrete-filled mild steel tubular columns under static and impact
loading. The dynamic moment capacity of hollow and concrete filled columns under
impact loading indicated a significant increase, compared to the capacity associated with static loading. Han et al. (2014) experimentally and numerically (using the
program ABAQUS) investigated the response of high strength concrete (compressive
strength up to 75 MPa) filled steel tubular specimens subjected to transverse impact
by conducting the drop hammer test. The results showed that the CFST specimens
deform in a ductile manner and have good resistance under transverse impact load,
and the ductile damage model provided by ABAQUS/Explicit (Karlsson Sorensen
Inc 2005) package can accurately predict the impact behavior of CFST specimens.
Wang et al. (2013, 2015, 2016) performed an investigation into the impact behavior
of CFST members and FRP-concrete-steel double skin tubular members (compressive strength of concrete is 48.7 ~ 60.2 MPa). The influences of the axial load level,
confinement factor (related to the yield strength of steel tube and compressive strength
of core concrete, as well as the cross-sectional area of both) and hollow ratio of
section were systematically discussed. The results showed that the axial load level
has a significant effect on the lateral deflections and the impact force–time histories
of CFST members, and the failure mode of specimens changed from brittle manner to
ductile manner with increasing the confinement factor. The main influencing factor
of peak impact force was hollow ratio of section for the FRP-concrete-steel double
skin tubular members. Furthermore, a finite element (FE) analysis model was developed by using ABAQUS and verified. Du et al. (2018) experimentally and numerically studied on the behavior of concrete (compressive strength of 31.2 MPa) filled
circular steel tubular members under lateral impact loading. The results showed that,
with increasing the outer diameter or the thickness of steel tube, the flexural deformation and mid-span deflection of specimens became less obviously but the peak
impact force increased. Then a three-dimensional FE model was established by using
ABAQUS, and the accuracy of the proposed model was verified by comparing with
the test data.
8 Response of UHPCC-FST Subjected to Low-Velocity Impact
transverse impacts. It was shown that the concrete filled steel square beams demonstrate significant reduction in transverse failure deflection and much superior energy
absorption capacity compared to the hollow steel square beams. Remennikov et al.
(2011) experimentally and numerically (using the program LS-DYNA) investigated
the impact behavior of square hollow section tubes filled with the rigid polyurethane
foam (RPF) and the normal weight concrete (compressive strength of 41 MPa). It
was indicated that the square concrete-filled tube has the highest impact resistance
and energy absorption capacity, followed by the square RPF-filled tube and then
the square hollow tube. Deng et al. (2012) conducted drop hammer impact test on
simply supported circular CFST, circular post-tensioned concrete-filled steel tube
(PTCFST) and circular steel fiber reinforced concrete-filled steel tube (FRCFST)
specimens with the compressive strength of concrete less than 60 MPa. It was derived
that, the PTCFST and the FRCFST specimens demonstrate superior impact resistance than the regular CFST specimens, and using the pre-stressed strands and steel
fibers can effectively restrain the cracks in the tension area of the core concrete.
Yousuf et al. (2012) performed an experimental study to investigate the behavior
of hollow and concrete-filled mild steel tubular columns under static and impact
loading. The dynamic moment capacity of hollow and concrete filled columns under
impact loading indicated a significant increase, compared to the capacity associated with static loading. Han et al. (2014) experimentally and numerically (using the
program ABAQUS) investigated the response of high strength concrete (compressive
strength up to 75 MPa) filled steel tubular specimens subjected to transverse impact
by conducting the drop hammer test. The results showed that the CFST specimens
deform in a ductile manner and have good resistance under transverse impact load,
and the ductile damage model provided by ABAQUS/Explicit (Karlsson Sorensen
Inc 2005) package can accurately predict the impact behavior of CFST specimens.
Wang et al. (2013, 2015, 2016) performed an investigation into the impact behavior
of CFST members and FRP-concrete-steel double skin tubular members (compressive strength of concrete is 48.7 ~ 60.2 MPa). The influences of the axial load level,
confinement factor (related to the yield strength of steel tube and compressive strength
of core concrete, as well as the cross-sectional area of both) and hollow ratio of
section were systematically discussed. The results showed that the axial load level
has a significant effect on the lateral deflections and the impact force–time histories
of CFST members, and the failure mode of specimens changed from brittle manner to
ductile manner with increasing the confinement factor. The main influencing factor
of peak impact force was hollow ratio of section for the FRP-concrete-steel double
skin tubular members. Furthermore, a finite element (FE) analysis model was developed by using ABAQUS and verified. Du et al. (2018) experimentally and numerically studied on the behavior of concrete (compressive strength of 31.2 MPa) filled
circular steel tubular members under lateral impact loading. The results showed that,
with increasing the outer diameter or the thickness of steel tube, the flexural deformation and mid-span deflection of specimens became less obviously but the peak
impact force increased. Then a three-dimensional FE model was established by using
ABAQUS, and the accuracy of the proposed model was verified by comparing with
the test data.