Tuned Mass Dampers: A Smart Component in Sustainable Laboratory Design

Michael Wesolowsky, Ph.D., P.Eng., Swallow Acoustic Consultants Ltd.

In the pursuit of more sustainable construction practices, advanced materials and design techniques have led to lighter and more flexible structural systems in buildings. These lightweight systems are unfortunately more susceptible to structural vibration generated from both internal and external sources. Besides creating uncomfortable working conditions for the occupants of a building, sensitive laboratory equipment can be negatively impacted to the point that they lose their ability to function properly and reliably. In extreme cases, significant damage to the equipment can occur. This can often lead to conflict within the design team as vibration consultants recommend more robust construction around the area where sensitive equipment is to be located, while structural engineers, architects and sustainability consultants prefer to keep the structural elements at a minimum.

Tuned Mass Dampers (TMDs) are devices mounted in a structure that can oppose the motion of a floor which has been excited by occupant footfalls. They have been demonstrated to be effective either when considered during the design process, or in mitigation situations. If designed and implemented properly, they achieve three goals: (1) to maintain structural motion levels below commonly accepted criteria, (2) to optimize the size and configuration of the structural system in order to provide more usable space in a building, and (3) to minimize the environmental impact of the construction process through a saving in construction materials and their resulting CO2 emissions.

Traditionally, TMDs have only been used to control perceptible and excessive motions from wind loading and large crowd movement. This has been the result of the viscous dampers (analogous to automotive shock absorbers) normally used in the fabrication of TMDs which require large motions to engage. As such, they have not been used in laboratory applications due to equipment criteria which specify vibration levels far below perceptibility. With the advent of a new class of TMDs, it is now possible to use these smart devices to control imperceptible motions as required in a laboratory building.

If TMDs are used as part of the design strategy of a new laboratory, it will allow the structure to be built more sustainably through the reduction of unnecessary structural material. TMDs also allow for the retrofit of existing buildings that require a more stable flooring system, providing future flexibility for laboratory space programming.

Biography:

Dr. Wesolowsky brings 14 years of consulting and academic experience in the field of Acoustics, Noise and Vibration control to Swallow Acoustic Consultants Ltd. He completed his Doctorate and Masters in the field of Structural Dynamics, with emphasis on hysteretic modelling of seismic isolation and damping devices for buildings and cable-stayed bridges. He has published and presented several research papers in journals and international conferences. He is a Licensed Professional Engineer (P.Eng.) registered with the Association of Professional Engineers of Ontario. Dr. Wesolowsky is also a Sessional Faculty member in the Bachelor of Technology Program at McMaster University in Hamilton, Ontario.

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