Floor vibrations due to human excitation: damping perspective

High levels of vibrations can occur in floor systems due to excitation from human activities such as walking and aerobics. In building floors, excessive vibrations are generally not a safety concern for building floor systems but a cause of annoyance and discomfort. Excessive vibrations typically occur in: (a) light weight floors; (b) floor systems with low stiffness where the floor dominant natural frequency is close to the excitation frequency; and (c) floors with low damping. While the floor mass and stiffness are normally constant during the life of the structure and can be estimated with a high degree of accuracy, damping is more difficult to predict because it is mostly associated with non-structural components such as partitions, false floors, suspended ceilings and ducts as well as furniture such as filing cabinets and bookshelfs. Current trends in the building industry associated with using lightweight materials, long-span open-plan floors and adoption of the electronic office, give rise to the importance of understanding floor vibrations and specifically damping. This paper provides a summary of factors affecting floor vibrations and discusses available damping systems which can be used to reduce vibration levels in floor systems.