To lower the vibration level of a monumental staircase, one 500 lb tuned mass damper (TMD) was designed, fabricated, and appended to the structure. The natural frequency of the staircase was measured and used for tuning the TMD. Figure 1 shows the landing of the staircase with two of the measurement locations highlighted. Monumental aesthetically […]
Read MoreFollowing the evaluation of the dynamic attributes of a monumental staircase (in an upscale financial office building), one 500 lb tuned mass damper (TMD) was designed, fabricated, and shipped to the job site. Two views of the nearly completed staircase are shown in Figure 1. Monumental, aesthetically pleasing staircases are getting incorporated more and more […]
Read MoreHunter’s Point South Park is a breath-taking waterfront park located on the edge of the East River, in Western Queens, NY. The focal point of the park is Hunter’s Point South overlook, a beautiful cantilevered platform that offers unobstructed views of the New York skyline. The Overlook’s rather low fundamental frequency (3.5 Hz) combined with […]
Read MoreGrant 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 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 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 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 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 […]
Read MoreViscoelastic tuned mass dampers (TMDs) use viscoelastic (VE) material as the suspension element, in such a way that the material exhibits the functionality of both the energy dissipation device (viscous) and the restoring device (elastic). These tuned mass dampers are in general less costly than the more commonly used TMDs employing viscous dampers and springs […]
Read MoreThe focal point of the City of Vancouver, Washington’s new development along the Columbia River is a concrete cantilever pier with an iconic and attractive form. The pier’s triangular, post-tensioned concrete deck overhangs the water by 90 feet and provides an expansive view of the river. A cable system and 80-foot-tall mast support the deck. […]
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