Open Access
ARTICLE
Re-centering variable friction device for seismic control of structures
O.E. Ozbulut1, S. Hurlebaus1
1 Texas A&M University, College Station, Texas, U.S.A
Structural Longevity 2012, 7(1), 29-36. https://doi.org/10.3970/sl.2012.007.029
Abstract
This paper investigates the seismic response control of a nonlinear
benchmark building with a new re-centering variable friction device (RVFD). The
RVFD consists of three parts: (i) a friction generation unit, (ii) a piezoelectric actuator, and (iii) shape memory alloy wires. The friction unit and piezoelectric actuator compose the first subcomponent of the hybrid device that is a variable friction
damper (VFD). The clamping force of the VFD can be adjusted according to the
current level of ground motion by adjusting the voltage level of piezoelectric actuators. The second subcomponent of this hybrid device consists of shape memory
alloy (SMA) wires that exhibit a unique hysteretic behavior and full recovery following post-yielding deformations. In general, installed SMA devices have the
ability to re-center structures upon end of the motion and VFDs can increase the
energy dissipation capacity of structures. The full realization of these devices into a
singular, hybrid form which complements the performance of each device is investigated. A neuro-fuzzy model is used to capture rate- and temperature-dependent
nonlinear behavior of the SMA components of the hybrid device. A fuzzy logic
controller is developed to adjust voltage level of VFDs for favorable performance
in a RVFD hybrid application. Numerical simulations of seismically excited nonlinear benchmark building are conducted to evaluate the performance of the hybrid
device. Results show that the RVFD modulated with a fuzzy logic control strategy
can effectively reduce interstory drifts without increasing acceleration response of
the benchmark building for most cases.
Keywords
Cite This Article
Ozbulut, O., Hurlebaus, S. (2012). Re-centering variable friction device for seismic control of structures.
Structural Longevity, 7(1), 29–36. https://doi.org/10.3970/sl.2012.007.029