vibrationisolation

Vibration isolation refers to methods and apparatus used to prevent or greatly reduce the transmission of mechanical vibrations from a source to a receiver. The goal is to decouple components so that vibrations, noise, or disturbances do not propagate, improving performance, accuracy, or comfort. Isolation is achieved by introducing a mechanical impedance mismatch or controlled energy dissipation between the source and the sensitive element. Natural frequency, damping, and mass are key design factors.

Common approaches are passive, active, and semi-active. Passive isolation uses springs, mounts, or pads to create a low-pass effect; elastomeric mounts, coil or leaf springs, and air or hydraulic isolators store or dissipate energy. The system’s natural frequency is set well below the dominant excitation frequencies; increasing mass or stiffness and adding damping can widen the isolation band.

Active isolation uses sensors (accelerometers, velocity sensors) and actuators to counteract detected vibrations, often with a feedback or feedforward controller. Semi-active systems adjust stiffness or damping in real time (e.g., with magnetorheological fluids) without adding large actuation forces.

Applications include vibration-sensitive equipment such as precision microscopes and metrology instruments, laboratory benches, clean rooms, and machinery foundations. In buildings, seismic base isolation uses special bearings to reduce transmitted ground motion during earthquakes.

Performance is often described by transmissibility and the ratio of output to input vibration. The aim is to achieve low transmissibility over the frequency range of interest. Limitations include power requirements for active systems, nonlinear behavior at high displacement, and aging or temperature effects in elastomeric components.