(1). The FEM model can be used to simulate the failure mode and
dynamic responses of tubular T-joints subjected to lateral
impact loading with good precision. The FE analysis indicates
that the tubular joint experiences the coupled local and
global deformations during the impact loading.
(2). In the FE model, the failure modes of chord cross-section at
different time points are captured to decipher the impact
force versus time history relation of the tubular T-joint.
Seven typical time points in the impact force versus time
history curve are identified to highlight the deformational
development of the tubular T-joint.
(3). The FE modeling is used to distinguish the local deformation
from the global deformation in order to discover the failure
mechanism of tubular T-joints under impact loading. The
failure mechanism of tubular T-joints is dominantly
controlled by the progressive local indentation of steel tube
close to the brace-chord connection zone. The failure
mechanism also can be verified by the time history of the
ratios of the local indentation dissipated and global bending
dissipated energy to the total plastic deformation energy.
Accordingly, the steel tubular T-joint under impact loading is
vulnerable to local indentation.
(4). Based on the simplified yield line pattern of the locallydented
top surface of chord and the reciprocal theorem of
work, an equivalent impact force estimation method is
developed in this paper to determine the anti-impact resistance
of steel tubular T-joint. It provides an effective method
for evaluating the impact resistance of steel tubular joint and
anti-impact design of steel tubular structures