Grant Street Pier, the focal point for “The Waterfront” development in Vancouver, WA is an attractive, triangular, post-tensioned concrete deck overhanging the water by 90 feet providing an expansive view of Columbia River. A cable system and 80-foot-tall mast support the deck. Since the pier is intended for visitors walking on it as well as […]
Read MoreExcessive vibration of a long span balcony (mezzanine) in an upscale residence was addressed by using a tuned mass damper tuned to the natural frequency of the first structural mode of the balcony. The TMD was sized to have the nominal active mass of 450 Kg. The depth and height of the TMD were chosen […]
Read MoreThe irregular shape of three large, 1200 square feet, cantilevered balconies in a high-profile performing arts center resulted in areas at the balcony tip and edge susceptible to potentially annoying levels of vibration. To mitigate this effect, the building designers added tuned mass dampers (TMDs) to the underside of each of the three balconies. Following […]
Read MoreExtensive vibration measurements and numerical analysis of the 2nd floor of a pharmaceutical laboratory floor system conducted by the acoustics consultant of the project revealed that the vibration levels at various bays were well above the laboratory vibration criteria. In coordination with the structural design team, contractor, and client, a two-phase retrofit scheme was proposed […]
Read MoreThe composite floor system of a large multipurpose room on the third floor of the admission building at a state university exhibited noticeable vibration caused by walking. The composite floor system consists of three long and narrow bays. The vibratory attributes of the floor system established by numerical analyses and measurement revealed the presence of […]
Read MoreThe vibration of an elevated floor system with long-span trusses supporting sensitive medical imaging equipment was mitigated through a combination of tuned damping, increased stiffness in the floor framing, and load distribution between adjacent bays. Given the stringent vibration criteria for medical imaging floor systems, neither stiffening—even by a large margin—nor tuned damping of reasonable […]
Read MoreTuned mass dampers (TMDs) were used to abate resonant vibration of the floor system induced by the rhythmic (dancing) perturbation at an upscale intimate concert venue/night club. The composite floor system is made up of 2.5” lightweight concrete on 3” deep, 20 gauge steel deck supported by wide flange steel beams and girder framing. The […]
Read MoreTuned mass dampers (TMDs) are tuned damping devices commonly used for dampening the vibration of a structure at a particular resonant frequency. TMDs come in various configurations. The commonality between all of them is their make-up which includes an inertia element (mass) suspended by an energy dissipating (damping) device and a restoring (resilient) element. Foot […]
Read MoreFloor Vibration Control Using Tuned Mass Dampers Tuned mass dampers (TMDs) are tuned damping devices commonly used for dampening the vibration of a structure at a particular resonant frequency. TMDs come in various configurations. The commonality between all of them is their make-up which includes an inertia element (mass) suspended by an energy dissipating (damping) […]
Read MoreTuned mass dampers (TMD) are highly effective and tunable passive vibration damping treatments. These devices are damped 2nd order systems appended to a vibrating structure; see Figure 1. Proper selection of the parameters (mass, stiffness, and damping) of a tuned mass damper, tunes the TMD to one of the natural frequencies of the underdamped flexible […]
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