adminDAMPERS
Dampers are devices used to control the motion of a system by dissipating energy built up or generated by the system such as mechanical, vibration, seismic or airflow systems with the aim of reducing motion or energy built up or generated, usually in the form of noise, heat or otherwise.
There are several types of dampers and they are; viscous, viscoelastic, tuned mass (TMD), tuned liquid (TLD), magnetorheological (MR), metallic, HVAC (airflow), electromagnetic and piezoelectric dampers.
Viscous dampers use a viscous fluid to dissipate energy. They consist of a piston moving in a cylinder filled with a viscous fluid such as oil or silicone. The movement of the piston in the fluid filled cylinder dissipate built up energy in the form of noise and heat energy .Example of viscous dampers includes; automobile shock absorbers, Taylor devices, fluid dampers, seismic shock absorbers, viscous dampers in bridges etc.
Friction dampers work by generating friction between two surfaces. This rubbing action of the two surfaces generates energy that is dissipated as heat and noise. Example of friction dampers includes; brake pads in vehicles etc.
Viscoelastic dampers combine the properties of viscous and elastic materials to dissipate energy. Example of viscoelastic dampers includes; vibration isolators, 3M viscoelastic dampers etc.
Tuned mass dampers (TMDs) consist of a mass attached to a spring and a dash pot. They are designed to resonate at a specific frequency, absorbing energy from the system. Example of tuned mass dampers (TMDs) includes; tuned mass damper installed on top of Taipei 100 skyscraper in Taiwan, Citicorp center New York etc.
Tuned liquid dampers (TLDs) uses liquid such as water or oil to dissipate energy. They consist of a tank filled with liquid and a tuned mass. Example of tuned liquid dampers includes; tuned liquid dampers system installed to reduce wind induced oscillation on Tokyo tower in japan etc.
Magnetorheological (MR) dampers use a magnetorheological fluid, which changes its viscosity in response to a magnetic field. They consist of a piston moving in a cylinder filled with MR fluid. Example of magnetorheological (MR) dampers includes; some high performance vehicles such as Chevrolet corvette, Lord corporation MR dampers etc.
Metallic dampers use a metallic material such as steel or aluminum to dissipate energy through plastic deformation. Example of metallic dampers includes; seismic isolators used in buildings, buckling restrained braces (BREs), ADAS/TADAS dampers etc.
HVACs (heating, ventilation and air conditioning) dampers are used to control airflow in HVAC systems. They consist of a valve or a blade that adjusts to control airflow. Example of HVAC dampers includes; butterfly dampers, damper valves etc.
Electromagnetic dampers use electromagnetic forces to dissipate energy. They consist of a coil and magnet where the coil generates a magnetic field that interacts with the magnet, creating a damping force. Example of electromagnetic dampers includes; electromagnetic shock absorbers, electromagnetic vibration isolators etc.
Piezoelectric dampers use piezoelectric materials to dissipate energy. These materials generate an electric charge in response to mechanical stress. Example of piezoelectric dampers includes; piezoelectric vibration isolators, piezoelectric dampers etc.
The advantages of dampers are; dampers convert vibration energy into heat and noise reducing damage to structures and equipment. Dampers protect buildings, bridges and machinery from seismic, wind induced or other types of vibrations. Dampers extend the service life of machines, equipment and structures by reducing fatigue stress on structural and machine components. dampers enhance the ride quality of occupants in building and vehicles by minimizing sway, noise and vibration from the inducing vibration sources. Dampers can improve the stability of systems by reducing the amplitude of oscillations and preventing resonance.
The disadvantages of dampers are; dampers can be expensive to install, maintain and operate, especially advanced dampers such as MR and active damping systems. Dampers require periodic maintenance, which may involve servicing, fluid replacement or outright replacement. Many dampers have limited effective range such as TMDs, which are tuned to specific frequencies and lose effectiveness outside that range. Dampers further add complexity to a system such as sensors, controllers and power requirements, imposing or increasing the failure points and design complexity of the system. Dampers increase the weight and space required in structural and mechanical systems, making them unsuitable in applications where weight and space is a constraint. Dampers are sensitive to environment conditions such as temperature, which may make their use not suitable in application where temperature is a major constraint.
Dampers find applications in the following; civil and structural engineering where they are used for seismic protection, wind-sway control in skyscrapers and bridge stabilization; automotive and aerospace, where they are used as suspension systems, shock absorption and vibration isolation in vehicles and aircrafts; HVACs and building systems, where they are used for air flow control, fire and smoke containment; industrial machinery, where they are used for vibration isolation of rotating equipment and dynamic machines to reduce wear and noise; dampers are used in renewable energy systems such as wind turbines towers to reduce wind induced vibrations. Dampers are used in consumer products as door closers, soft close furniture mechanisms, appliances vibration control etc.
The future of dampers is based on the advances and development of the following technologies; development of new materials, such as advanced composites and smart materials to improve their performance and efficiency. There will be increased use of active dampers which can be adjusted in real time to cope with changing operational scenarios. Dampers will be increasingly integrated with sensors, control systems and AI algorithms to optimize their performance and efficiency. Dampers will be developed to recover dissipated energy and convert to usable electricity. Dampers will be designed to be sustainable such that they can be recyclable after prolong use. Dampers will be further miniaturized and 3D printed to produce custom light weight damping solutions for use in specialized applications like robotics, micro devices etc.
SOURCES:
- Theory of vibration with applications by William T. Thomson and Marie Dillion Dahleh.
- Fundamentals of vibration by Leonard Meirovitch.
- Vibration of structures induced by wind and earthquake by Yukio Tamura and Ahsan Kareem.
- Vibration damping by R.G Owens.
- Damping in mechanical systems by C.M Harris.
