Active Vibration Dampers of Buildings and Structures Operated under the Reactive Jet Principle

The article considers controlling vibratory motion dynamics using active dampers, making it possible to significantly reduce the level of mechanical vibrations of buildings and structures. A controlled reactive damper can be considered a highly efficient method of damping structural vibrations of structures under nonstationary (seismic) impacts. The reactive damper activation process is controlled by the “coordinate – damper electric drive” pair. Motion tracking is done via special sensors for determining linear and angular displacements. The operation principle of a reactive damper involves creating an alternating reactive force to prevent relative (bending) displacements (vibratory displacements) of a structure at target time instants. Several ways of creating a reactive jet (reactive forced action on a mechanical system) are shown: a reactive fluid jet ejected under high pressure; a reactive gas jet flowing under high pressure; a reactive jet from a burning fuel. The relations for calculating their influence are presented. The finite element method (FEM) motion equations for a construction node with an attached reactive damper are given for the central difference approximation of derivatives and using the Newmark method.