Abstract:
In construction of modern buildings, the presence of openings became a necessary nowadays in
order to accommodate many pipes and ducts required for the different services. On the other hand,
the presence of these openings in RC T- beams affects their structural behavior. Because of the
change in the beam section the corners of the opening are subjected to large concentration of
stress, possibly producing cracks in the beam. The region nearby the openings is measured as the
weaker part of the beam.
In this study, a three-dimensional nonlinear finite element analysis using ABAQUS program had
been employed to simulate simply supported reinforced concrete T-beams with and without web
openings, which was subjected to concentrated load at mid span. Four study parameters were
considered, including effect of size of circular web opening, shape of web opening, location of web
opening and number of web opening (one and two) on the behavior of the RC T-beams. To verify
whether finite element simulation process is correct finite element result was compared with
experimental test and show good agreement. T-Beams were simulated to obtained the load
deflection relationship and ultimate load and compare them with solid reference one.
Result obtained from this study showed that reinforced concrete T- beam with small circular web
opening of dimeter 50mm or 21% of web depth has small effect (2.9% reduction) but, circular web
opening of dimeter 140mm or 60% of web depth has large effect (25.8% reduction) on load
carrying capacity of reinforced concrete T- beam. The presence of web opening at 300mm from
support of reinforced concrete T- beam reduce load carrying capacity up to 25% and at 750mm
from support reduce load carrying capacity up to14.2% in comparison with control beam. From
square, rectangular and circular shape of opening circular one has less effect and best shape of
opening and regarding location of opening, web opening at 750mm has less effect on reduction in
strength of T-beam. Placing two web opening in both sides of the supports was better than one
opening but effect of number of opening (one and two) is small at all when compare with shape,
size and location of web openings. Finally, circular web openings are highly recommended.
