The 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 housing sensitive medical imaging equipment was mitigated using tuned damping in conjunction with stiffening of the floor framing and load spreading between adjacent bays. {With the very stringent criterion on vibration levels associated with the medical imaging floor systems neither stiffening (even by a […]
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 […]
Read MoreThe airframes of some airplanes are equipped with a number of tuned vibration absorbers tuned the propeller blade passage frequency, to cancel out the noise and vibration and keep the cabin quiet and comfortable. A number of the DVAs in a private airplane were removed from the airframe, disassembled and their leaf springs refurbished. Following […]
Read MoreA small room is used to evaluate how DEICON’s patented, active acoustic damping technology, ‘electronic bass trap’, enhances low-frequency musical articulation in that room The rectangular room has a dominant coloration due to the 32 Hz standing wave that shapes up along its length. Electronic bass trap is used to add damping to the first […]
Read MoreProof mass actuators (PMAs) are used to add tuned damping and tuned dynamic absorption to test structure as well as the rear sub-frame of an all-wheel-drive vehicle. The choice of active vibration control strategy, with a PMAs as the actuator, depends on whether the PMA’s natural frequency is placed below or within the frequency(ies) of […]
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 More