Dynamic fracture behavior analysis of FRP-strengthened concrete based on
DIC and AE technology
Abstract
In order to analyze the fracture behavior of FRP-strengthened concrete
beams under dynamic loads, three-point bending dynamic tests of
FRP-strengthened concrete beam specimens with four different initial
crack-depth ratios (0.2, 0.3, 0.4 and 0.5) were carried out in this
paper. The crack propagation was quantitatively analyzed by acoustic
emission (AE) technique and digital image correlation (DIC) method, and
the toughening mechanism of FRP-strengthened concrete beam during crack
propagation was studied. The test results show that, there are three key
points in the failure process of FRP-strengthened concrete beams with
cracks, which are the crack initiation point, crack resistance point and
peak load point, respectively. The load values at the three key points
of FRP-strengthened concrete beams with cracks decrease with the
increase of initial crack-depth ratios. The location analysis of AE
shows that the number of AE events can be used to indicate the crack
width in the fracture process zone (FPZ) of FRP-strengthened concrete.
The crack width of concrete beam specimens can be quantitatively
determined by DIC and decrease with the increase of initial crack-depth
ratios, indicating that observation results of DIC and AE technology are
consistent, which is effective for characterizing the dynamic fracture
behavior of concrete materials.