Abstract
A unified design model is proposed for various kinds of passive dynamic absorbers (PDAs) attached to buildings with different lateral resisting systems. A total of five different PDAs are considered in this study: (1) tuned mass damper (TMD), (2) circular tuned sloshing damper (C-TSD), (3) rectangular tuned sloshing damper (R-TSD), (4) two-way liquid damper (TWLD), and (5) pendulum tuned mass damper (PTMD). The unified model consists of a coupled shear-flexural (CSF) discrete model with equivalent tuned mass dampers (TMDs), which allows the consideration of intermediate modes of lateral deformation. By modifying the nondimensional lateral stiffness ratio, the CSF model can consider lateral deformations varying from those of a flexural cantilever beam to those of a shear cantilever beam. The unified model was applied to a 144-meter-tall building located in the Valley of Mexico, which was subjected to both seismic and along-wind loads. The building has similar fundamental periods of vibration and different nondimensional lateral stiffness ratios for both translational directions, which shows the importance of considering both bending and shear stiffness in the design of PDAs. The results show a great effectiveness of PDAs in controlling along-wind RMS accelerations of the building; on the contrary, PDAs were ineffective in controlling peak lateral displacements. For a single PDA attached at the rooftop level, the maximum possible value of the PDA mass efficiency index increases as the nondimensional lateral stiffness ratio decreases; therefore, there is an increase in the vibration control effectiveness of PDAs for lateral flexural-type deformations.
Highlights
Increasing urbanization in recent decades has led to the construction of high-rise buildings, which are usually susceptible to wind loads worldwide
CPDA 2ξPDAmPDAwPDA, where μ is the pendulum tuned mass damper (PTMD)/single degree of freedom (SDOF) nondimensional mass ratio that may be chosen in the range of 1/50 to 1/15 for a first design approach [38]; mSDOF is the structural mass of an equivalent SDOF system, which was defined in equation (2); g is the gravitational acceleration; lp is the pendulum length; ξPDA is the damping ratio of the PTMD; and wPDA is the angular frequency of the pendulum, which is given by the following equation:
The following conclusions were obtained: (a) For the first mode of vibration, the structural mass of an equivalent SDOF system at lower stories increases as the nondimensional lateral stiffness ratio decreases; on the contrary, for upper stories, it increases as the nondimensional lateral stiffness ratio increases. erefore, if a single passive dynamic absorbers (PDAs) attached at the rooftop level is tuned to the first mode of vibration, the maximum possible value of the mass efficiency index of the PDA increases as the nondimensional lateral stiffness ratio decreases
Summary
Increasing urbanization in recent decades has led to the construction of high-rise buildings, which are usually susceptible to wind loads worldwide. For high-rise buildings with large mass and low frequencies, a cable-supported pendulum system in which the natural frequency is tunable by changing the pendulum length is highly recommended [25] For both seismic and wind loads, Gerges and Vickery [26] proposed optimum design parameters for PTMDs by using equivalent TMDs. Shu et al [27] implemented the performance-based analysis and design methodology to assess the seismic vulnerability of a coal-fired power plant and to optimally design its equivalent pendulum-type tuned mass damper system such that the direct losses are minimized. CPDA 2ξPDAmPDAwPDA, where μ is the PTMD/SDOF nondimensional mass ratio that may be chosen in the range of 1/50 to 1/15 for a first design approach [38]; mSDOF is the structural mass of an equivalent SDOF system, which was defined in equation (2); g is the gravitational acceleration; lp is the pendulum length; ξPDA is the damping ratio of the PTMD; and wPDA is the angular frequency of the pendulum, which is given by the following equation:.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
