structureborne

Structureborne refers to vibrations and related noise that travel through solid materials such as beams, floors, walls, and foundations, rather than through the air. It originates when a vibrating source excites a structure, causing it to radiate sound to surrounding spaces or pass vibration to connected components and receivers.

Common sources include rotating machinery, impact events, traffic, and industrial equipment. Transmission paths depend on how the source is mounted and connected to the structure; energy can travel through bearings, bolted joints, and mounting pads, then reflect, resonate, or radiate as airborne sound at different points.

Measurement and analysis: Structureborne vibration is typically quantified with accelerometers or velocity sensors attached to surfaces, sometimes using laser vibrometry. Metrics include surface velocity or acceleration, transmitted power, or sound power radiated by a structure. Analysis methods include transfer path analysis, modal analysis, and vibro-acoustic coupling models to locate dominant paths and resonances.

Mitigation: Approaches include isolating the source from the structure with vibration isolators, decoupling mounts, or floating foundations; adding damping treatments; changing mass or stiffness to shift resonances; applying decoupling at critical joints; and using active vibration control in some cases.

Applications and context: Structureborne noise is a major concern in buildings, vehicles, and machinery where vibrations couple into floors, walls, or chassis, affecting comfort, operation, and compliance with noise criteria. It is often addressed together with airborne noise in a holistic vibro-acoustic design.