نوع مقاله : پژوهشی
نویسندگان
1 دانشکده ی مهندسی عمران، دانشگاه فردوسی مشهد
2 دانشکده ی مهندسی عمران، د دانشگاه فردوسی مشهد
3 دانشکده ی فنی و مهندسی عمران، دانشگاه تهران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Post-tensioned coupled shear wall system is characterized by good seismic
specifications like a self-centering capability and an ability to sustain large
nonlinear lateral deformations with little damage and negligible residual
deformation. In this system, the coupling beam is not embedded into the walls,
and coupling of concrete walls is performed by posttensioning beam to the walls
using unbonded post-tensioning (PT) steel strands. In this paper, the seismic
behavior of hybrid coupled wall systems with post-tensioned steel coupling beam
was investigated experimentally. In order to dissipate seismic energy and
reduce displacements of system, two friction dampers were used in the
beam-to-wall connection region. To study the behavior of the system, a friction
damper was first tested at different frequencies; then, four 2/3-scale
posttensioned hybrid coupled wall sub-assemblages equipped with friction
dampers were tested subjected to reversed-cyclic lateral loading. Each
sub-assemblage included a half-length steel coupling beam and the adjacent
concrete wall region at a floor level. The test specimens consisted of one
control specimen without friction damper and three specimens equipped with
friction dampers with various damper normal forces and different initial beam post-tensioning (PT) steel stresses. The test results showed that the system had very good lateral stiffness, strength, and ductility with little damage up
to 8% lateral drift. The nonlinear deformation in this system occurs because of
the gap opening at the beam-to-wall interface. The friction damper uses these
gap opening displacements to provide supplemental energy dissipation. Friction
dampers provide considerable energy dissipation at the system, while the
self-centering capability of the system remains. The restoring effect of the
post-tensioning steel strands causes closing the gap upon unloading and
provides a self-centering behavior and flag-shaped hysteresis loops for
specimens equipped with friction dampers. Based on the test results, the
system, even after a severe earthquake, suffers limited damage and requires
little repair.
کلیدواژهها [English]
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