Damper
How does a viscous damper reduce structural stress during seismic events?
It dissipates energy by generating a damping force out of phase with bending stresses, reducing stress and deflection by up to 50% in some frames.
What reliability factor is required for hysteretic dampers under EN 15129?
The standard mandates a reliability factor (γₓ) for base isolation devices when combined with dampers, ensuring design displacement capacity exceeds γₓ·γᵦ·d_bd.
Can dampers eliminate vibration entirely?
No; dampers attenuate motion but rarely eliminate it, primarily reducing amplitude, controlling settling time, and limiting overshoot.
A damper is a device that reduces the amplitude of motion, vibration, or flow by converting kinetic energy into heat, friction, or fluid resistance to attenuate unwanted dynamic behavior. In industrial contexts, dampers are energy dissipation attachments designed to improve system reliability and reduce failure risk from dynamic loads like seismic, wind, or mechanical vibration. Common types include viscous, hysteretic (yield), friction, and tuned mass dampers (TMDs).
On the shop floor, dampers are installed on rotating machinery such as motors, pumps, and fans to suppress resonance and limit vibration amplitudes that cause bearing wear or seal failure. In CMMS systems like ServiceGrid, dampers are tracked as critical reliability components with maintenance tasks for leak inspection (hydraulic/viscous types), seal integrity checks, and calibration (for TMDs). Maintenance strategies include time-variant reliability analysis to assess performance degradation due to wear, corrosion, or fluid leakage over time.
Fluid leakage in viscous/hydraulic dampers, leading to loss of damping force and uncontrolled oscillation.
Corrosion or wear of mechanical contact points, reducing friction damping efficiency and causing premature failure.
Incorrect tuning of TMDs (oscillation frequency mismatch with structure’s resonant frequency), resulting in ineffective vibration suppression and increased dynamic stress.