Posts Tagged with Vibration Control

Isolation System for an Industrial Process Equipment Subject to Random Vibration

  The support structure of a massive, 110,000 lb, industrial process equipment, subject to random perturbation, is isolated from the vibration of the equipment itself.  The isolators used in the random vibration isolation system are made up of low-stiffness springs paired with viscous dampers. Motion control schemes were incorporated into the isolation system to manage […]

Read More

Advanced Air Isolation System for Precision Devices

Precision devices such as coordinate measuring machines (CMMs), microscopes, MRI machines, and other test/scanning equipment are highly sensitive to vibration, caused by other nearby equipment or even human activities. The adverse effects of vibration on such devices should be mitigated by properly isolating them from the surrounding via elastically mounting them on their support concrete […]

Read More

Passive Electronic Damping

Passive electronic damping using piezoelectric ceramics is a less temperature-sensitive and more tunable alternative to viscoelastic damping treatments. In this damping technique, the mechanical energy of the structure is converted to electrical energy using piezoelectric material. High mechanical stiffness of piezoceramics enables efficient energy transfer to the piezo damper. The electrical energy, in turn, is […]

Read More

One-Order Tuned Vibration Absorption of a Diesel-Generator

In four stroke engines, including diesel engines driving generators, each cylinder fires every other revolution. This causes the engine vibration to occur at ½ the engine RPM, called the ½ order vibration, and its higher order harmonics namely 1 order, 1½ order, 2 order. In the case of a diesel generator, in addition to the […]

Read More

Active Tuned Mass Dampers

The extent of vibration energy that a passive TMD dissipates as well as its effective frequency range (bandwidth) increase with an increase in the mass ratio of the TMD. In addition, the amount of internal damping built into the make-up of a passive TMD increases with the size of that TMD. The TMDs used in […]

Read More

Self-Tuning of Tuned Dampers/Absorbers

The use of a tuned damper or a dynamic absorber in time-varying systems can only be effective if they are adjustable (semi-active) and continuously returned to the current resonant frequency of the system. Such dampers require a tuning algorithm that can automatically adjust the adjustable parameter of the tuned damper/absorber, e.g., the stiffness of the […]

Read More

Monumental Staircase Vibration Abatement Using a Tuned Mass Damper-2

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 More

Vibration Abatement of a Monumental Staircase Using a Tuned Mass Damper

Following 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 More

Vibration Control of an Overlook Using Tuned Mass Dampers

Hunter’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 More

Vibration Control of a Concrete, Cantilever Pier Using Tuned Mass Dampers

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 More